Polypipe Under Floor Heating Systems Technical document

TIG1 JULY 2009
EFFECTIVE: 1ST JULY 2009
Under Floor Heating Systems
Technical Installation Guide
July 2009
Technical Installation Guide
Under Floor Heating Systems
Polypipe Building Products
Broomhouse Lane
Edlington
Doncaster DN12 1ES
Tel: [phone]
Fax: [phone]
2410 London Road
Mount Vernon
Glasgow G32 8XZ
Tel: [phone]
Fax: [phone]
Dromore Road
Lurgan, Craigavon
Co. Armagh BT66 7HL
Tel: [phone]
Fax: [phone]
www.polypipe.com
Under oor heating systems trade website: www.ufch.com
Under oor heating systems consumer website: www.freeyourwalls.com

Polypipe oor heating products, excluding manifolds and control products, are covered by a 50 year guarantee*, which protects against
defects in materials or manufacture of the heating system from date of purchase. This guarantee only applies if the system is installed
in accordance with the manufacturer’s recommendations contained within the Technical Installation Guide (the latest version of which
can be found at www.ufch.com), and is used in a normal domestic operation. This document should be read in conjunction with all other
documentation supplied with Polypipe products.
If you have any queries please contact our Technical Department on 01709 770000.
*Full terms and conditions for Polypipe heating products 50 Year Guarantee are available at www.ufch.com
CONTENTS
How to use this guide ............................................................................................................03
INTRODUCTION
About Polypipe ......................................................................................................................04
An overview of under oor heating systems ...........................................................................06
Selecting the right Polypipe under oor heating system ..........................................................07
System selection ....................................................................................................................08
Design service ........................................................................................................................09
Guide to oor coverings for under oor heating systems ........................................................10
INSTALLING THE SYSTEM
Solid Floor ..............................................................................................................................12
Floating Floor .........................................................................................................................16
Suspended Floor ....................................................................................................................18
Modular Heating Panel ..........................................................................................................22
Overlay™ ...............................................................................................................................28
Overlay™ Lite ........................................................................................................................36
CONNECTING & CONTROLLING THE SYSTEM
Connecting to heat source .....................................................................................................38
Manifolds ..............................................................................................................................39
Water temperature controls ...................................................................................................40
Room temperature controls ...................................................................................................41
Single room applications ........................................................................................................44
System commissioning ...........................................................................................................46
TECHNICAL DATA
Heat output tables .................................................................................................................48
General system information ...................................................................................................49
FAULT FINDING CHARTS
Hydraulic fault nding chart ...................................................................................................50
Electrical fault nding chart (master connecting box) ..............................................................51
STANDARDS
Accreditations, standards and guarantees ..............................................................................52
FORMS
1-2-3 Product selection form ..................................................................................................53
Design enquiry form ..............................................................................................................54
LITERATURE
Other information and literature ............................................................................................55
02 03
HOW TO USE THIS GUIDE
Important notice:
This publication is provided as a comprehensive guide on how to install Polypipe
under floor heating systems. It is an important document as we cannot accept any
liability, or honour any guarantee, for products and systems that have not been
installed in accordance with our published instructions.
From time to time our installation advice may be updated
at which time previous printed copies will become out of date.
The latest version of our installation advice, including a downloadable
version of the current Technical Installation Guide, can be found
at our trade website, www.ufch.com
Selecting the right system
This guide is intended for competent trained plumbing and
heating installers and we assume that you will have already
specied your system of choice before consulting this publication
for installation advice. Basic information on selecting the right
system is provided in this guide. For more detailed guidance
refer to our Design & Specication Guide or visit our trade
website at www.ufch.com or consumer website at
www.freeyourwalls.com
Navigating the Technical
Installation Guide
Having read the general introductory sections at the front
of the guide, ensure that you have selected the correct system
for your oor type and project. Read the guide to oor coverings
to ensure that your system is compatible with your oor type.
Next, choose your selected under oor heating system type from
the section “Installing the system” and follow the step by step
instructions. Everything should be straightforward but remember
that the Polypipe Technical Support team is always ready to help
answer any questions you may have.
Whichever Polypipe under oor heating system you are installing
you will need to refer to the information provided in the section
“Connecting and controlling the system”. This section provides
all you need to know about manifolds and controls, connecting
your system to an appropriate heat source and commissioning
the system.
Technical data
Towards the back of this guide you will nd technical data such
as heat output tables, pipe data and general system information
as well as useful forms to use with our Product Selector
and System Design Service.
Additional information
Should you have any questions at any time, or require any
kind of technical support call our Technical Support team
on 01709 770000.
Online assistance is available at www.ufch.com, our comprehensive
website for installers, developers and merchants. As well as
information on technical advice and product benets, you can
nd useful case studies and details of Polypipe stockists.
Video instructions on under oor heating installation are also
available to view.

04 05
ABOUT POLYPIPE UNDER FLOOR HEATING Easy installation
Polypipe under oor heating systems have been designed with
ease of installation in mind. Innovative product designs ensure
minimal disruption to existing heating and electrical supplies
during installation. As our systems are compatible with standard
central heating boilers, connectivity is also streamlined. Polypipe
under oor heating systems can be installed up to 20% quicker
than radiators.
Polypipe under oor heating systems are installed in one stage,
eliminating the need for a time consuming second x. Under oor
heating components are much easier to manoeuvre on site than
large, bulky radiators; reducing handling issues and potential
damage. Unlike radiators, there is also very little theft value
during installation.
Details of each type of Polypipe under oor heating system can
be found on page 6.
Maintenance free
Once installed, a Polypipe under oor heating system is virtually
maintenance free. There are no joints in the pipe work within the
ooring, signicantly reducing the possibility of leaks. Polypipe
under oor heating products are subjected to rigorous testing
and meet a number of exacting standards, full details of which
can be found on page 52. All our manufacturing processes are
monitored and controlled in accordance with the international
quality standard BS EN ISO 9002.
Choosing under oor heating also eliminates a number of
general maintenance and decoration requirements, normally
associated with radiators, such as painting the radiator or
removing it to paint the wall.
Demonstrating the utmost condence in product performance,
and providing our customers with peace of mind, Polypipe under
oor heating systems are covered by the Polypipe 50 year
guarantee (full details can be found at www.ufch.com).
Easy to control
Polypipe manufactures a range of water and room temperature
control solutions, allowing you to source a complete, integrated
system from a single supplier. The range includes a number of
control products, with options to suit a variety of lifestyle
patterns, and the abilities to control different rooms independently.
Full details of Polypipe control products can be found on pages
40 to 43.
Flexible approach
Polypipe under oor heating systems use the exibility of polybutylene
pipe to provide a solution for all house and room types. We also
have a range of unique and innovative products, including the
Zonal Regulation Unit (ZRU) which is an excellent enabler allowing
under oor heating systems to be incorporated into single rooms
or refurbishment projects with minimal disruption to existing
heating and electrical supplies.
For more information on our single room applications see pages
44 and 45.
Excellent service
At Polypipe we understand that selecting the right solution for
each application involves detailed consideration. This is why we
offer extensive customer service support, including free system
design and full technical support if any problems arise. We want
to ensure that your installation runs smoothly from the beginning
and our technical support staff can assist you with any questions
you might have.
During installation we offer:
• Pre-project training at one of our training centres
• Pre-project training by distance learning
• On-site assistance
We also provide an extensive back up service:
• Technical representation available to discuss systems in general
and particular projects
• www.ufch.com
• Technical Installation CD
• Specialist Technical Hotline on 01709 770000
Energy efficient
Under oor heating systems can be more economical to run
than radiator based systems. As they demand a low temperature
rise output from the boiler, they are ideally suited to achieving
maximum economy from a condensing boiler or heat pump.
However, they are just as efcient with higher temperature heat
sources, for example solar and solid fuel, where the correct water
temperature can be set at the point of distribution.
Polypipe is one of Europe’s largest manufacturers of specialist plastic plumbing,
heating, waste and drainage products.
Our market leading under floor heating product range has been continuously
developed and improved with frequent innovative additions, the latest of which
are Modular Heating Panels (MHP) - a revolutionary solution for suspended floor
applications - and Overlay™ Lite, a lightweight floor panel to complement our
innovative over floor heating range.
Polypipe is a member of the Underfloor Heating Manufacturers’ Association (UHMA),
who set and enforce standards for materials, design and installation of under floor
heating systems - standards that we embrace within every aspect of our range.
Polypipe under oor heating systems have been designed with
speciers, installers and users in mind.
Our systems combine ease of installation with reliable long-term
performance, and we hold a range of stock ready for prompt
dispatch. Unique to the Polypipe service proposition is our
room and house packs concept. Recognising that under oor
heating systems are difcult to specify using individual components,
we created a range of over 300 pre-set combinations that can
be ordered as complete kits. By simply specifying key variables
such as oor type, room size, control and circuit data the right
pack can be specied in minutes. It’s as easy as .
We have even created a unique online product selection tool.
Following recent innovative product introductions, we have
categorised our range into 3 groups in order to make selecting
even more instinctive:
With a long established reputation for product quality and
value, backed by our strict trade-only distribution policy,
Polypipe has become the clear leader in the under oor
heating category. Recent innovations ensure the Polypipe
range is the widest available from a single manufacturer,
including traditional under oor heating systems for every
oor type as well as the innovative MHP and Overlay™ products.
Polypipe under oor heating systems are ideal for every
application, including new build, self build, renovation and
home improvement projects. Whole house, single oor and
single room projects are equally catered for in our extensive
product offering. Whatever job you are undertaking, Polypipe
has the product to suit.
Polypipe is a recognised and respected brand, and is well
established as the system of choice for domestic homes by
many installers. All Polypipe under oor heating systems are
supplied as a complete system, and require no additional
components for installation. Polypipe under oor heating
systems are rigorously tested, and comply with (or exceed) all
relevant UK standards. We use an integrated exible plumbing
system, incorporating polybutylene pipes and a range of push-
t ttings. The systems are also designed for use with copper
pipes, allowing the integration of rigid pipes when necessary.

OVERLAY™
LITE OVERLAY™
SOLID
FLOOR
FLOATING
FLOOR
06 07
AN OVERVIEW OF UNDER FLOOR
HEATING SYSTEMS
SELECTING THE RIGHT POLYPIPE
UNDER FLOOR HEATING SYSTEM
Polypipe has the widest available range of under floor heating systems, with a
product available for every conceivable floor type or residential heating project.
With Polypipe, under floor heating is not restricted to new build developments or
self build projects. Our unique Overlay™ product is particularly well suited to single
room projects such as kitchens, bathrooms, conservatories, extensions and loft
conversions. Polypipe Modular Heating Panels (MHP) were developed to provide an
innovative and practical solution to installing under floor heating into upper floors.
The notes below provide a brief overview of the methodologies
employed to install under oor heating systems for various oor
types. Refer to the overview on the page opposite. Full installation
instructions for each oor type can be found in the section titled
‘Installing the system’ on pages 12 to 36.
Solid Floor
Polypipe under oor heating can be permanently built into solid
concrete or screeded oors. As required by current Building
Regulations, insulation is built into the oor directly beneath the
unique Polypipe lightweight plastic oor panel. The heating pipe
is simply slotted into the panel and then permanently covered by
the screed. Suitable for all oor coverings, solid oor systems can
incorporate 15mm or 18mm pipe.
The oor panels form a simple grid for the quickest possible
pipe laying and provide a precise guide to achieve the minimum
bending radius. Panel castellations are set at exact centres and
hold the pipe against movement when screeding. The oor panel
holds the pipe above the insulation allowing full screed surround.
Optimum screed depth is 65mm from the panel base, i.e. 40mm
from the pipe top. Insulation below and at the edges of the oor
screed is required by Building Regulations. Edge insulation also
acts as an expansion joint.
Floating Floor
When installed in oating oors, Polyplumb pipe is simply pressed
in to the pre-formed heat spreader plate, which sits in grooves
within the oating oor insulation panel. The oating oor
system is then covered with 18mm chipboard sheeting. Suitable
for all oor covering, oating oor systems can incorporate
15mm or 18mm pipe.
Suspended Floor
For installations in suspended oors, Polypipe under oor heating
uses double heat spreader plates. Alternatively, pipes can be laid
on top of insulation between joists. Standard tongue and groove
oorboards are laid on top of the system. Suspended double heat
spreader plate systems use 15mm pipe.
MHP (Modular Heating Panels)
Modular Heating Panels offer a revolutionary new way to solve
the issue of installing under oor heating into upper oors. MHP
is available in two widths and two lengths to t all standard joist
spacings. All components and circuitry is pre-congured into
the panels which are simply installed between the joists, linked
together and connected to the manifold.
Overlay™
Overlay™ allows under oor heating to be installed into existing
spaces quickly, easily and practically. The unique system is
supplied with a choice of patented low prole panels to suit all
types of oor coverings. The Overlay™ system is laid over existing
solid or timber oors.
Under floor heating systems
Product selection: Typical applications and features
New build Existing floor
SUSPENDED
FLOOR
Under floor
All floor
coverings
High mass
system
Typical ground
floor or beam
and block
construction
All floor
covering
except natural
wood/thick
laminates
Lightweight
construction
No wet trades
required
Lightweight
floor coverings
Larger areas
Multiple rooms
Tiles or
natural wood
Wet areas
Over floor
MODULAR
HEATING
PANEL
All floor
covering
Fit from above
Traditional
joists
Traditional
heat source
All floor
coverings
Fit from
above/below
Traditional
or engineered
joists
Traditional or
renewable heat
sources
SUSPENDED
FLOOR

08 09
SYSTEM SELECTION
Our comprehensive system
design service includes:
• System design, including heat loss calculations
for residential applications
• Circuit lengths
• Circuit pressure losses and velocities
• Flow rate settings per circuit
• Full product material specication
Installation service
• Pre-project training at training centre
• Pre-project training by distance learning
• On-site assistance if required during project installation
Backup service
• Technical representation available to discuss systems
in general and particular projects
• Web-site and information on CD
• Specialist Technical Hotline on 01709 770000
Polypipe has removed the mystique from specifying the correct under floor
heating solution for a given project and the need to calculate all of the individual
components required. Our unique Product Selector, which is available
on page 53 or online at www.ufch.com, uses a simple 3 step process to calculate
your requirements using basic project data that you provide. The system includes
details of over 300 pre-configured system kits that contain all of the parts and
components you need. Once you have determined the correct pack for your
project it can be ordered under a single item code via your merchant.
DESIGN SERVICE
For projects that fall outside the scope of the room packs or house packs,
Polypipe offers a fully bespoke system design service. To utilise this facility, simply
complete the enquiry form on page 54, or at www.ufch.com, and submit your
drawings to Polypipe. You will then receive a complete design and component
list for the project.
To use the Polypipe Product Selector you rst decide whether
the project is a single room, a whole house solution, or requires
a bespoke design. You then simply input data for each room,
providing oor type, room size, and control zones to calculate
the required pack.
All packs have a single order code and include all the necessary
ooring materials, pipe, distribution (manifolds, ZRU, etc.),
water temperature and room temperature controls.
To select the appropriate solution, choose from the
following options:
Room Packs
Room packs are designed for single room applications: i.e. kitchens,
bathrooms, conservatories, loft conversions and extensions.
This range of under oor heating packs contain all the ooring
and control equipment required for a single project, in solid oor,
our traditional Overlay™ and our NEW Overlay™ Lite systems.
All room packs have a maximum heat output of 100W/m2.
House Packs
House packs provide you with a quick and easy way to select and
order from our range of under oor heating products, without the
need to submit a design. The packs are designed for solid, oating
or suspended (double heat spreader plate) projects.
Packs can be applied to all new build or renovation properties that
fall into the following criteria:
• Rooms requiring up to 70W/m2
• Properties built to current Building Regulations
• Projects where the manifold can be positioned within 6m
of the room entrance
Design services
For projects that fall outside the scope of the room packs
or house packs, Polypipe offers a fully bespoke system design
service. To utilise this facility, simply complete the enquiry form
on page 54, or at www.ufch.com, and submit your drawings
to Polypipe. You will then receive a complete design and
component list for the project.
Modular Heating Panels
Our revolutionary new MHP panels, designed to make under
oor heating easier to install between ceiling joists for upper
oor suspended oor applications, have their own product
selector, which is also available online at www.ufch.com

10 11
GUIDE TO FLOOR COVERINGS
FOR UNDER FLOOR HEATING SYSTEMS
Under floor heating systems will work efficiently with any floor covering, as long as it
is well insulated underneath. However, each covering has different thermal conduction
properties, and harder surfaces offer better conductivity and, therefore, better heat
output rates. The following notes provide some guidance on each type of covering.
Vinyl
Suitable for all Polypipe under oor heating systems:
Sheet vinyl is sensitive to long term exposure to heat. There are
two categories of vinyl; one is limited to constant temperatures
of around 26°C and the other to 30°C. Check the oor surface
temperature indicated by your vinyl supplier for compatibility
with under oor heating. If unsure contact the Polypipe hotline
or the vinyl oor manufacturer.
Laminate
Suitable for all Polypipe under oor heating systems:
Laminate ooring should be laid on roll type oor leveller,
rather than the rigid panel type. Movement that occurs must
be accommodated by an expansion gap around the oor deck.
Timber
Suitable for Polypipe solid oor and suspended oor systems:
Concerns regarding the effect of heat on a timber oor are
misplaced. The more important issue is the oor moisture
content. Timber oors should be laid at a moisture content
of 10-11%, which when heated will reduce to 8-9%, and cause
only a very small amount of shrinkage. The oor will re-absorb
some moisture when the heating is not operating and the
moisture content will increase to 12-13%. Further details
on installing timber oors over Polypipe under oor heating
systems can be found on page 15.
Carpet and underlay
Suitable for all Polypipe under oor heating systems:
The nature and thickness of the carpet underlay is fundamental
in determining good heat transfer. The most popular underlay
type is sponge with a wafe pattern moulded into the underside.
These allow good heat transfer. Felt and rubber crumb underlay
should be avoided. These products can seriously reduce the
effectiveness of an under oor heating system, as they insulate
the oor surface and prevent heat transfer.
The TOG value of carpet and underlay should be available from
the respective manufacturer. For optimal system performance
choose an underlay with a maximum TOG value of approximately
0.5. The maximum TOG value of carpet should be approximately
1.0 to 1.5.
Stone and ceramic tiles,
marble or flagstones
Suitable for all Polypipe under oor heating systems:
These types of oor nishes are usually cold underfoot.
However, with oor heating they are transformed into warm
comfortable surfaces. Each of these nishes is essentially
brittle and it is imperative that the design of the supporting
oor structure is stable and rigid to prevent cracking.
It is recommended that exible adhesives and grout be used.

Pre-installation requirements
The sub oor must be swept clean and be free from mortar residues.
Installation
Fitting Insulation
Step 1:
In accordance with Part ‘L’ of the current Building Regulations,
a suitable layer of insulation material should be included within
the oor construction. It is the responsibility of the Architect or
Builder to ensure compliance. However, in all instances insulation
must be installed beneath the under oor heating system in order
to ensure that any downward heat loss does not exceed 10W/m2,
in accordance with BS EN 1264.
Fitting the edge insulation strips
Step 2:
Using edge insulation strip allows the free expansion of the oor
screed. The insulation strip should be installed around all perimeter
walls and xed constructions such as columns, steps and access doors.
Edge insulation strip is bent at 90° near to the base to form
a double sided self-adhesive strip which bonds the oor plates
to the oor insulation. Edge insulation strip should be tted in
addition to perimeter insulation required by Building Regulations.
Fitting the floor panels
Step 3:
The oor panels are laid over the pre-installed insulation and
should be overlapped at the edges.
NOTE: The ½ castellation should overlap the ¾ castellation. The rst
panel should be laid with the ½ castellation edge against the wall.
Panels can be cut by simply using a saw or snips or it can
be overlapped to the nearest castellation t.
Floor panels should not be used at the base of the manifold
as pipes need to be closer together than the oor panels allow.
Pipes around this area should be secured using pipe clips which can
also be used intermittently to secure the clip plate to the insulation.
When a pumped (liquid) screed is to be used it is essential that all of
the panel joints are made correctly and that no panels are allowed to
simply ‘butt-up’ as this may allow the screed to penetrate below the
under oor heating system and cause the panels to rise up. Similarly
the panels should be rmly secured around the perimeter of the room
using staples so as to prevent possible risk of the panels lifting.
Preparing the pipe
Step 4:
You will need to remove the coil from the bag, leaving the shrink
wrap on, uncoiling from centre of the coil.
Laying the pipe
Step 5:
Once you have completed laying the solid oor panels the pipe
can be tted starting at the manifold position in line with the
pre-designed centres. 15mm and 18mm pipe can be laid
at 100mm or 200mm centres as required, 18mm pipe can also
be laid at 300mm centres.
The minimum bend radius is achieved by encircling two
castellations for a 90° bend or three castellations for a 180° bend
(see diagrams on next page).
12 13
SOLID FLOOR
Key design and installation information
Material requirements (approx)
Maximum heat output Approx. 100W/m2
Recommended design ow temp 50°C
Maximum circuit length 100m (15mm pipe)
120m (18mm pipe)
Maximum coverage per circuit 12m2 at 100mm centres
22m2 at 200mm centres
30m2 at 300mm centres*
*(18mm pipe only)
Pipe 8.2m/m2 at 100mm centres
4.5m/m2 at 200mm centres
3.3m/m2 at 300mm spacing*
*(18mm pipe only)
Floor plate usage 1 plate/m2 allowing
for cutting
(Actual 1·2m2/plate)
Edging insulation strip 1.1m/m2
Conduit pipe 2m/circuit
Polypipe under floor heating in solid or screeded floors incorporates the unique
Polypipe screeded floor panel. The lightweight plastic floor panels nest
for easy storage and carrying.
Polypipe has the perfect solution for installing under oor
heating into solid or screeded oors. Utilising our unique
lightweight plastic oor panels, which are quick and easy to
cut to size, it is possible to t Polypipe under oor heating into
any shaped room.
Polypipe solid oor panels form a simple grid to ensure the
fastest possible pipe laying and also provide a precise guide
for the pipe, ensuring that the minimum pipe bending
radius is achieved.
The panels are laid above pre-installed insulation and the
system includes edging insulation strip to ensure maximum
performance and efciency.
Polypipe under oor heating systems can be used with
the following solid oor constructions:
• Sand & cement screed (4:1 mix)
• Pumped screed systems (anhydrite, etc)
• Fine or heavy concrete
• Polymer modied screeds

Step 6:
Circuits being laid at 100mm or 200mm centres must be laid in a spiral
conguration. The rst loop of pipe should be laid around the perimeter
of the area to be covered by that circuit. The next loop of this circuit
should be laid either 200mm from the rst loop of pipe for 100mm
centres or 400mm from the rst loop of pipe for 200mm centres.
Step 7:
Continue to loop the pipe into the centre of the panels leaving
enough space to form a double return (‘S’ shape in the centre
of the loop).
Step 8:
Now work back out from the centre by lling the space between the
inwardly spiralling loop of the primary circuit ensuring the pipe is laid
at the correct spacing centres.
18mm pipe installation formation
Where 300mm centre spacing is require (18mm pipe systems only)
a meander pattern can be used. The pipe simply crosses the room
from one side to the other encapsulating 3 castellations at each
return bend.
Conduit pipe
A 400mm length of conduit pipe should be tted over the under oor
heating pipe in any situation where damage may be caused to the
pipe i.e. where the pipe passes through internal walls or doorways,
where the pipe emerges through the oor up to the manifold
or where the pipe passes through either an expansion or day joint.
Preformed long radius bends can also be used to provide a neater
solution if required.
A section of conduit pipe 400mm long should be tted around the
heating pipe where the pipe passes through the edge insulation strip,
e.g. room to room, or through expansion joints within the oor.
Conduit pipe should also be used where the pipe leaves the oor
adjacent to the manifold. This can be threaded down the pipe
after the pipework has been installed.
14 15
Expansion joint
BS EN 1264-4 recommends that an expansion joint is constructed
in stone and ceramic nished screeds for every 40m2 of oor area
at a maximum length of 8m and an aspect ratio of 2:1.
An expansion joint is also required in long narrow areas such
as corridors, etc.
The image below shows a typical arrangement where the pipes
pass through either an expansion or a day joint. A strip of edge
insulation is used to provide the expansion capacity.
For further information regarding oor screeding requirements
for under oor heating systems please refer to BS8204-1 or the
BISRIA Guide: Screeds with Under Floor Heating.
Testing
Step 9:
Once the pipes circuits have been installed and pressure tested the
screed cover can be applied. Care should be taken to ensure that
the screed is tightly compacted around the pipe to ensure that no
voids are present. The system should remain under pressure (6 bar)
in order to prevent the risk of any damage being caused to the
walls of the pipe whilst the screed is being applied.
Laying the screed
Step 10:
The overall quality and thickness of a sand and cement screed
should meet the requirements of BS8204-1 which stipulates that
in domestic or light commercial applications a minimum thickness
of 65mm should be used. The thickness of alternative coverings,
such as anhydrite or polymer modied screeds, may differ depending
on construction requirements. This information should therefore
be provided by the specialist screed manufacturer/supplier.
After the screed has been laid the oor should be covered with
a membrane to retard the drying out process, particularly in warm
weather. The oor should be allowed to cure and dry naturally until
full strength is reached in accordance with relevant British Standards
and manufacturers’ instructions (approx 30 days for sand and
cement and concrete oors). Under no circumstances should the
under oor heating system be used to articially dry/cure the screed
as this could cause the screed to crack and seriously undermine
the integrity of the oor construction. Once the screed has fully
cured the under oor heating system can be switched on and the
manifold ow temperature slowly increased up to the calculated
design temperature.
Finishing
Timber floors
Many people are concerned by the effect of heat on a timber
oor, but this concern is misplaced. The important factor is the
oor moisture content.
Timber oors can be laid directly over the screed at a moisture
content of 10-11% which during the heating season will reduce
to 8-9% and may cause a small amount shrinkage.
The oor will re-absorb some moisture when the heating is not
operating and the moisture content will increase to 12-13%.
Application of timber floors over solid floor systems
Where solid oak ooring is to be laid on a solid oor, joists can
be tted at 1m centres to provide a xing point for the boards.
Insulation, solid oor panels and pipe can be laid between
the joists and screed laid level with the top of the joists
(see diagram below).
Individual circuits of pipe are then laid between each set of joists
with care being taken to ensure the screed is completely dry prior
to tting the solid oak covering (see diagram).
90° 180°
Screed
Timber floor covering
Solid floor plate
Joist at 1m spacings
Pipe
Conduit
Insulation
Sub floor

Pre-installation requirements
The sub oor must be swept clean and be free from mortar residues.
Installation
Laying the floating floor panels
Step 1:
Lay the 1200 x 1200 x 50mm oating oor panels directly over
the entire oor area to be heated, ensuring the panel grooves are
aligned. The panels can be cut to t where necessary.
A void in the insulation is often retained around the edge of the
room to allow for distribution pipes to be laid from the room
to the manifold.
Laying the spreader plates
Step 2:
Single heat spreader plates that have pre-formed grooves at
300mm centres need to be laid on top of the oating oor panels.
These plates ensure an even spread of heat across the oor area
and hold the pipe rmly within place in the oating oor panel.
Laying the pipe
Step 3:
Once you have completed laying the oating oor panels and heat
spreader plates the pipe can be tted into the pre-formed grooves of
the heat spreader plate. Start at the manifold position and use the
grooves in the oating oor panel to loop round the entire room.
The maximum circuit length is 80m using 15mm pipe or 100m
using 18mm pipe. Pipe should be laid in the pattern shown below.
NOTE: Areas of potential high point loading, e.g. under heavy
furniture kitchen units and appliances, will require additional oor
support. Timber battens (50mm x 50mm) should be positioned
between the oating oor panels and notched to allow the passage
of pipes.
Testing
Step 4:
Once the pipe circuits have been installed and connected to the
manifold the system should be pressure tested to 6 bar for a
minimum of 1 hour before the timber oor covering is laid. It is
recommended that the system remains under pressure whilst the
ooring is laid.
Finishing
The room can then be nished by tting 18mm or 22mm tongue and
groove sheets of chipboard, glued on the edge, over the oating oor
system. Mark the position of the pipe where door thresholds or carpet
strip are to be installed.
When laying a ceramic or stone oor covering ensure that any
deection in the oor is minimised. It is recommended that a slip mat
or uncoupling membrane is used rather than a second layer of wood.
The Polypipe floating floor system is designed for use in applications where a solid
floor installation is not suitable due to structural weight limitations or where a
‘dry build’ floor option is required. Suitable for use in either new build or existing
properties, the floating floor panels can be installed directly on top of both solid
and timber floors.
The 50mm thick high density polystyrene panels have a
thermal value of 0.036W/mK and can be used to enhance
the thermal insulation requirement of the oor structure as
required under current Building Regulations. However, care
should be taken when installing oating oor panels on top
of a primary insulation layer to ensure that excessive deection
does not occur in the nal oor construction.
It is therefore recommended that any other insulation
materials used below the oating oor panels are of a high
density construction (100kN/m2 @ 10% compression min).
16 17
FLOATING FLOOR
Key design and installation information
Pipe 3.1m/m2 at 300mm centres
Floating oor panel 1 panel/1.4m2
Single spreader plate 3 plates/m2
Material requirements (approx)
Maximum heat output Approx. 70W/m2
Recommended design ow temp 60°C
Maximum circuit length 80m (15mm pipe)
100m (18mm pipe)
Maximum coverage per circuit 25.8m2 at 300mm centres
(15mm pipe)
30m2 at 300mm centres
(18mm pipe)
Polyplumb
barrier pipe
Single heat
spreader plate
Insulated floating
floor panel

18 19
SUSPENDED FLOOR Pre-installation requirements
Installation
Fitting nsulation
Step 1:
Before installing a suspended oor system it is necessary to insulate
between the joists. Polypipe recommend that a rigid polystyrene
or foam insulation material is used.
Fitting the spreader plates
Step 2:
The insulation layer should t tightly between the joists directly
below the spreader plate to ensure that the spreader plate is
supported and therefore remains in contact with the underside
of timber oor covering. This is necessary to eliminate any air
gaps or draughts between the under oor heating system and
the oor.
Any other services, such as drainage or electrical wiring, should be
installed below the insulation layer.
The oor joists then need to be notched or drilled in accordance
with Building Regulations. This facilitates the passage of the pipe
between the joist gap to allow the entry and exit of the pipe
to and from the room.
The spreader plates can then be xed evenly across the joists and
in accordance with your installation design.
Laying the pipe
Step 3:
Once the spreader plates have been xed in place the pipe can
be tted in to the grooves in a meander pattern. It is recommended
that the ow pipe from the manifold be taken to the furthest point
of the room when installing the circuit as this ensures that sufcient
heat is provided around the perimeters of the room.
Care should be taken when installing the pipe to ensure the
spreader plates are not pushed downwards and away from the
underside of the timber nished oor covering as this could lead to
potential underperformance of the system.
Testing
Step 4:
Once the pipe circuits have been installed and connected to
the manifold the system should be pressure tested to 6 bar for
a minimum of 1 hour before the timber oor covering is laid.
It is recommended that the system remains under pressure whilst
the ooring is laid.
Double heat
spreader plate
Pipe
Return
Flow
Joists notched to
accept pipe returns
Designed for use in timber suspended or battened floors the Polypipe suspended
floor system uses aluminium double heat spreader plates to transmit the heat
evenly across the finished floor surface.
Suitable for joist widths of 300mm to 450mm the spreader
plates are simply xed to the joist using small nails or staples.
The pipe is then run in to the preformed grooves of the
panels which are designed to hold the pipe securely at
225mm average centers.
A layer of insulation below the panels will ensure that almost
all of the heat generated passes up in to the room.
The Polypipe suspended oor system is also suitable for use
with ‘sprung’ ooring systems as used in sports halls, etc.
Key design and installation information
Material requirements (approx)
Maximum heat output Approx. 70W/m2
Recommended design ow temp 60°C
Maximum circuit length 80m (15mm pipe)
Maximum coverage per circuit 17m2 at 225mm average
double heat spreader plates (15mm) centres
Double heat
spreader plates
Pipe 4.5m/m2
Heat spreader plates 2 plates/m2
Ceiling
Polyplumb
barrier pipe
Polystyrene
or foam insulation
Supporting joists
Tongue & groove flooring
Double heat
spreader plate
450mm
1000mm
250mm

20 21
Pipe only systems
The use of heat spreader plates is recommended, as they assist the
response time and heat dispersion. However, in some circumstances,
simply laying pipe in an air void between foil faced reective
insulation and the underside of the oorboard will be adequate.
The space between the top of the insulation and the underside
of the oor deck should be kept to a minimum (20mm) and care
should be taken to ensure that the insulation is sealed at the
edges and ends.
Pipe only applications are suitable in areas where the heating response
is less important, e.g. bedrooms, and is not recommended in living
spaces or over unheated spaces, e.g. rooms above garages.
Enhancing pipe only systems
The effectiveness of pipe only systems can be enhanced by laying
a weak (1:6) dry mix screed approximately 25mm thick between
the joists.
In order to apply this, extra support may be required below the
insulation. Although pipe only systems are designed to operate
at 60°C ow temperature, the ow temperature may be reduced
in these circumstances.
Before this system is considered it is suggested you consult
a structural engineer to conrm its suitability.
Finishing
Laying a timber floor covering
Step 5:
It is strongly recommended that the timber oor covering is laid
immediately after the under oor heating pipes have been installed
and pressure tested to eliminate any risk of damage to the system
by other trades.
Either traditional tongue & groove oorboards or 18mm/22mm
chipboard can be tted directly on top of the spreader plates.
These can be xed directly through the spreader plate down in to
the joists below. It is important to indicate the position of pipework
in areas where the additional xing of items such as carpet grip rod
or door threshold strips may be tted at a future date.
Polypipe does not recommend the application of two layers of
timber oor covering as this will severely reduce the heat output of
the under oor heating system.
Correct application
Incorrect application
If a manufactured timber oor is to be used then it is recommended
that this be of a suitable load bearing quality. (Please request advice
from the specialist ooring supplier).
Battern systems
Used for spans greater than 450mm or less than 350mm.
Where it is not possible or desirable to drill or notch the oor joists,
and the oor height can be raised, spreader plates can be used.
Fitting insulation with a battern system
Step 1:
To prevent downward heat transmission, insulate between the
voids in the joists with appropriate foam insulation.
Fitting the batterns
Step 2:
Lay 75mm x 25mm battens across the existing joists at 450mm centres.
Trim the ends of the batten back to the last joist at alternative ends.
Fitting the spreader plates
Step 3:
Lay spreader plates between the battens and pin in position.
Laying the pipe
Step 4:
Lay pipe into the spreader plates in accordance with the installation
instructions on the previous page, ensuring you follow the
testing procedure.
Joists at spacing
greater than
450mm or less
than 350mm
Polyplumb
barrier pipe
Pipe clip
75mm x 25mm
battens at
450mm centres
Polyplumb
barrier pipe
Double heat
spreader plate
Joists at spacing
greater than 450mm
or less than 350mm
25mm thick dry
mix screed
Insulation
Tongue and
groove flooring
Joists

MODULAR HEATING PANEL
22 23
Maximising heat efficiency
Product options
A new concept
in under floor heating
Modular Heating Panels* are an exciting new product concept from Polypipe
that enable quick and simple installation of under floor heating into suspended
floors in both new build and renovation projects.
Installing under oor heating into upper oors can be
challenging, even in new build projects. Most conventional
under oor heating systems comprise a single section of pipe,
housed or placed within another part of the system structure,
such as oor panels, which are cut to size on site. This works
ne as there are no interruptions to the laying of the pipe.
In suspended oor installations however, the pipe, plates and
insulation have to t within an obvious obstruction:
the supporting oor joists. It is working around the joists,
and avoiding other services, that has often led to under oor
heating being avoided in upper oors.
As the name suggests, a Modular Heating Panel (MHP)
is a pre-congured solution, where all of the oor heating
system components are supplied tted within complete panels,
which are simply tted and connected together on site.
Thanks to MHP it is now possible to t panels quickly
into the existing joist voids and connect them to a standard
heat source.
MHP works with both traditional and engineered joists and
can be tted from above or below.
Due to their high output at relatively low ow temperatures, Modular Heating Panels are ideal for maximising heat efciency
and lowering energy consumption. In most installations it is not necessary to cover the entire oor area. MHP panels work like
“under oor radiators”, applying enough heat to only those areas of the oor that need to be heated and using just enough
of them to maintain a suitable room temperature.
For a room temperature of 20°C, for example, only 80% oor coverage is required to provide 70W/m2 or around 60% for 50W/m2.
This unique product benet also makes MHP an ideal solution when using heat pumps.
The exibility of panel placement provided by MHP means that oor areas to be covered by items such as built-in wardrobes
or baths and shower cubicles can be avoided without detriment to the overall heating provision.
MHP is available in 4 panel sizes comprising 2 lengths and 2 widths:
MHP available lengths: 1.3m and 2.0m
MHP available widths: 380mm and 490mm
Each MHP panel contains pre-installed pipe circuitry, 30mm
of insulation, and is covered in heat diffusing foil. Pipe circuitry
is based on 10mm diameter pipe. A 500mm length of pipe
extends from each panel allowing connection to the ow and
return pipe work from an under oor heating manifold.
MHP panels are easily installed from either above or below
and suit the joist widths of both composite ‘I’ beam joists and
traditional timber joists. Up to 3 MHP panels can be connected
together in series and the recommended maximum room area
per circuit is 20m2.
Heat diffusion foil
30mm insulation
10mm pipe circuit
*Patent pending.

Designing your layout
Designing the ideal room layout for an MHP installation and
selecting the required products couldn’t be simpler.
Follow the steps below or use the online product selector tool
at www.ufch.com/mhp
Select panel width
Step 1:
The spacing of joists and the available gap will determine which
MHP panel width will be most suitable for each project. Select the
MHP width nearest to the gap width, ensuring that this does not
encroach on the space for other services.
The 490mm width panel will normally be tted in the wider joist
spacing used by composite joists and ‘I’ beams.
Select panel length
Step 2:
The span of the joists in each room will determine which MHP panel
length should be selected. The span is dened as the free space
from wall to wall that needs to remain uninterrupted by trimmers
or other services. Ideally, install MHP panels prior to other services
whenever possible.
Use the table below as a quick guide to suitable arrangements
of MHP panels leaving a 200mm gap for pipe connections.
24 25
Planning your room arrangement
Step 3:
Calculating the amount of oor area to be covered by MHP will be
based on the required heat output (see our heat output tables on
page 27) and will take into account areas of the oor that do not
require heating, such as under built-in wardrobes, baths and
shower cubicles.
The diagram below illustrates a typical layout that
might be considered.
1 x 1.3m Panel
SpanArrangement
1 x 2.0m Panel
2 x 1.3m Panels
1 x 1.3m Panel +
1 x 2.0m Panel
2 x 2.0m Panels
1.4m to 2.2m
2.2m to 2.8m
2.8m to 3.5m
3.5m to 4.2m
4.2m to 5.0m

26 27
Panel layoutsPre-installation requirements
Planning
Before installing MHP panels ensure you have planned out the
positioning of the required panels avoiding all other services such
as electrics, gas and water supply.
You will not need to do any specic preparation for the
installation in a new build property as there will be no ceilings
or oors in place.
For existing room refurbishment, you will need to take up your
oor if tting from above or take down the ceiling if tting from
below. Ensure that the area where the MHP panels are to be
positioned is free from any debris before commencing installation.
Installation
Installation from above
To install MHP panels from above simply t support bearers to
each side of the joists. These support bearers should be positioned
30mm from the top of the joist and the MHP panel is then simply
laid on to these supports.
Installation from below
When installing MHP panels from below you will need to mark
out the positioning of the panels to ensure you have them
situated in the correct places for heating the room above.
Once you have checked the marked out positioning, the MHP
panels can be slotted into place and xed to the underside
of the oor using 1¾” x 8 woodscrews with M6 x 30 dia washers.
It is advisable to use 6 xings per panel ensuring you avoid the
moulded pipe marking on the underside of the panel and x
each panel securely.
IMPORTANT NOTE: Polystyrene can cause deterioration to cable
insulation when it comes into direct contact with it.
Always ensure that electrical cables are not in physical contact
with the MHP panels using tape or a polythene strip.
Finishing
Once you have connected your system up to the manifold and
tested it you can then nish the room by tting the oor or ceiling
in the normal way depending on whether you have installed MHP
from above or below.
Testing
Where possible installations should be tested at 20°C to
18 bar pressure. Any installations once connected to the manifold
have a maximum test pressure of 6 bar.
Product Information
Product Code No of panels
per pack
MHP 490mm (W) x 2.0m (L) MHP49020 5
MHP 490mm (W) x 1.3m (L) MHP49013 5
MHP 380mm (W) x 2.0m (L) MHP38020 5
MHP 380mm (W) x 1.3m (L) MHP38013 5
Heat Output
Maximum oor area for ow and return 20m2
Room at 20°C Heat output per panel
Flow Av. floor MHP49020 MHP49013 MHP38020 MHGP38013
temp (°C) temp (°C) (W) (W) (W) (W)
40 25.0 63 42 49 33
45 25.8 75 50 58 39
50 26.6 86 58 67 45
55 28.9 120 80 93 62
60 30.8 147 99 114 77
Approximate coverage required:
For 70W/m2 room = 80% coverage
For 50W/m2 room = 60% coverage
Connect up to 3 panels in series
Maximum coverage per circuit 20m2
1 panel layout
15mm Polypipe flow and return
connections to manifold
15mm Polypipe flow and return
connections to manifold
Part No: PB010
10mm
Straight Coupling
Part No: PB010
10mm
Straight Coupling
Part No: PB1115
15mm - 10mm
Reduced Branch Tee
Part No: PB015
15mm
Straight Coupling
+
Part No: PB1815
15mm - 10mm
Socket Reducer
Part No: PB1115
15mm - 10mm
Reduced Branch Tee
+
Part No: PB1815
15mm - 10mm
Socket Reducer
Part No: PB1115
15mm - 10mm
Reduced Branch Tee
+
Part No: PB1215
15mm - 10mm
Reduced Branch
Spigot Tee
2 panel layout
1
1 2 3
2
3
4
4
5
5
6
6

OVERLAYTM
28 29
OverlayTM is a unique low profile floor
heating system ideal for both renovation
and new build projects.
Installed over the existing oor and only 18mm in depth, Overlay™ allows
oor heating to be installed where traditional under oor systems would
either require expensive excavation or would require the oor to be raised
to an unacceptable level.
The Overlay™ system is available in 2 panel types to allow for installation
to all build types and oor coverings.
Overlay™ panel is a brous panel used for heavyweight oor coverings such
as ceramics, or where the oor covering needs to be secured directly to the
panel, e.g. solid wood.
Overlay™ Lite is a high compressive strength, lightweight insulated panel
used for lightweight oor coverings, e.g. laminate, engineered wood and carpet.
Due to its ease of handling and cutting it is also more suitable for larger areas
and multiple room installations.
Overlay™ systems use a 12mm pipe at 150mm pipe centres and provide
excellent response times and heat output compared with traditional built
in under oor heating solutions and are therefore ideal for both traditional
heating systems and low temperature renewable systems.
Under floor heating
that fits over
existing floors

Key design and installation information
Material requirements (approx)
Maximum heat output Approx. 100W/m2
Recommended design ow temp 45° to 50°C
Maximum circuit length 80m
Maximum coverage per circuit 12m2
Overlay™ oor panel Coverage 0.48m2
Overlay™ Lite oor panel Coverage 0.75m2
Pipe 7m length/m2
End returns 1 return bend per oor panel
12mm x 80m coil of pipe 1 coil per circuit
15mm x 12mm adaptors & stiffeners 1 pack per circuit
30 31
Choosing your Overlay™ panel
Overlay™ accommodates all types of project and oor coverings and the only choice is that of which panel will be most
appropriate for the installation. Both Overlay™ and Overlay™ Lite can be used for the majority of projects, however as
Overlay™ Lite is the quickest and easiest system to install, this should be the rst consideration for most projects.
The more structural nature of Overlay™ however makes it ideal for direct tiling or application of oor nishes which need
to be xed or screwed to the panel.
6mm plywood lining
600mm x 1244mm
Overlay™ Lite panel
Heat diffusion foil
End return Suitable for:
Laminate
Vinyl
Carpet
12mm pipe circuit
18mm floor panel
Fits over concrete
or floorboards
OverlayTM Lite
for lightweight floor coverings
OverlayTM
for heavyweight floor coverings
Suitable for:
Tile
Hard wood
600mm x 800mm
Overlay™ panel
End return
12mm pipe circuit
18mm floor panel
Fits over concrete
or floorboards
Project type
Overlay™ Overlay™ Lite
Single room / small areas Yes Yes
Multiple room / large area With careful Yes
planning
Overlay™ Overlay™ Lite
Tiles / slate / other ceramics Direct With plywood
overboard
Natural wood Direct & xed No
Laminate Yes Yes
& engineered laminate
Carpet & vinyl With plywood With plywood
overboard overboard
Floor covering

32 33
Pre-installation requirements
Planning
Planning the Overlay™ system beforehand will save time during
installation and minimise product waste.
The direction the pipe runs to and from the ZRU or manifold and
use of the return bends will be the main considerations.
The end returns have a at panel which forms a channel to allow
the routing of pipes to multiple circuits in the room. This can be
removed where necessary.
Floor areas which don’t require pipe circuitry, e.g. beneath kitchen
cupboards or sanitary ware, can be ‘blanked’ using 18mm plywood
or chipboard. This will make better use of the Overlay™ products.
This can also be used to ‘square off’ rooms with irregular walls.
Example of ‘blanking’ on kitchen plan
Example of ‘blanking’ in a bathroom
Example of ‘squaring off’ an irregular room plan
Room layouts
The following diagrams show some examples of room shapes,
pipe requirements and interruptions (pillars, hearths, etc.)
which need to be accommodated.
Room with 2 circuits
Room with pillars/hearth
Pipe layouts in multiple room installations
Multiple room installations require several circuits and careful
planning is required close to the manifold to allow for all pipes
to be accommodated.
Wherever possible pipes can simply go through, rather than
round, walls to eliminate the number of pipes requiring access
through the entrance of the manifold cupboard.
Alternatively leave voids at the edge of the panels.
Using return bends as routers or using supply pipes
to heat corridors are all ways of managing the installation
in this area.
2
4
3
2
3 4
1
1
End Return
with panel
removed
End Return
End Return
with panel
removed
End Return

Step 3:
When you get close to end of the rst row t two end returns
against the wall as in step 1 and if necessary cut an Overlay™ panel
to t and complete the rst row.
Cutting the panels
Panels can be cut using a hand saw or jigsaw set at a low speed.
(Cutting these panels will generate dust so should either be done
outside or in a ventilated room. Ensure you wear a particle mask.)
Step 4:
Once you have completed the rst row begin the process again,
gluing the ends and sides of each panel, staggering the panels
in the second row in a brickwork pattern and continue until the
room is complete.
Laying the pipe
Step 5:
Starting from your manifold position and allowing enough pipe for
connections lay the pipe into the grooves of the Overlay™ panel
in accordance with your plan.
Finishing
Using a oor ller/grout ll any gaps and voids, and ll around
any pipework.
Tiles can be laid directly on to the Overlay™ panels or a 6mm
plywood lining can be tted prior to tiling.
When tiling directly over Overlay™ panels, use a sealant with exible
adhesive and grout.
If tting solid wood oors they can be discretely screwed through the
tongue and groove directly into the Overlay™ panel, avoiding pipe
circuitry, to minimise movement in the oor covering.
If over-boarding with 6mm plywood, this can be glued, stapled or
screwed to the Overlay™ panel, avoiding the pipe circuitry.
Plywood cover where required
34 35
Overlay™
for heavyweight oor coverings
Installation
Laying end returns
Step 1:
Start by xing two end returns to the oor in a corner of the room.
(Remove the pipe panel if not required as per your oor plan).
This should be done by using suitable screws in the screw holes
of the end return panels when xing to a wood oor, or by using
Overlay™ adhesive (code PB777) to bond the end returns
to solid oors.
Laying the panels
Step 2:
Clean down the edges of the panel and apply a 3mm bead
of adhesive to the top edge. Then lay it, ensuring you line up
the grooves in the panel with those in the end returns.
Continue to lay the rst row of panels gluing each joint
to achieve a secure installation.
When gluing the ends, ensure there is no residual glue in the pipe
grooves and use short lengths of pipe to help with panel alignment.
First panel
Room wall
Return bends
with pipe plate
remaining
Return bends with pipe
plate removed
First row Subsequent row

Step 4:
Once you have completed the rst row begin the process again with
the second row, staggering the panels in a brickwork pattern.
Step 5:
Use the self adhesive foil tape along the long panel joints to securely
x the panels to the adjacent row.
Step 6:
Now continue this process, completing the whole room.
Laying the pipe
Step 7:
Starting from your manifold position and, allowing enough pipe for
connections, lay the pipe into the grooves of the Overlay™ Lite panel
in accordance with your plan.
Step 8:
Once you have nished laying the pipe use the self adhesive foil tape
to secure the panels and pipe, running across all the panel joints, and
do the same across the joints where the panels meet the end returns.
Finishing
Laminate and engineered wood can be laid directly over Overlay™
Lite panels. Where carpet or vinyl is being tted, rst x a 6mm layer
of plywood using a contact adhesive, then continue to lay the oor
covering as normal. It is advisable to mark out pipe positioning
to avoid stapling pipes when tting carpets.
36 37
Overlay™ Lite
for lightweight oor coverings
Installation
Laying end returns
Step 1:
Start by xing two end returns to the oor in a corner of the room.
(Remove the pipe panel if not required as per your oor plan).
This should be done by using suitable screws in the screw holes
of the end return panels when xing to a wood oor or by using
Overlay™ adhesive (code PB777) to bond the end returns to
solid oors.
Laying the panels
Step 2:
Lay the panel ensuring you line up the grooves in the panel with
those in the end returns then continue to lay the rst row of panels
using short lengths of pipe to help with panel alignment.
Step 3:
When you get close to end of the rst row t two end returns
against the wall as in step 1 and if necessary cut an Overlay™
Lite panel to t and complete the rst row.
Cutting the panels
Panels can be cut using a sharp knife and a metal rule.
First panel
Room wall
Return bends
with pipe plate
remaining
Return bends with pipe
plate removed
First row Subsequent row

38 39
MANIFOLDS
Manifolds are common to all systems above 30m2, independent of the under floor heating
system. Manifolds are supplied complete and fixed to the wall mounting bracket.
The manifold comes complete with a drain and air vent assembly,
which can be positioned on either end of the manifold. Isolation
valves are supplied separately for the supply end of each manifold.
The bottom manifold is the ow and the top manifold is the
return. Each manifold port comes complete with a Polyplumb
push t connection. Pipes are connected to manifolds by
inserting a pipe stiffener into the pipe and simply push tting
the pipe into the port.
The ow meter on each ow port of the manifold provides
a visual indication of the ow through each circuit.
Both manual and lockshield balancing can be undertaken
by either using the blue cap on the return manifold for manual
adjustment, or removing the blue cap and adjusting using the
key supplied with each manifold.
Preparing and installing
the manifold
Remove the manifold from the box and arrange the ow and
return manifolds to ensure that the inlets/outlets are pointing
downwards. Remove the air vent and drain valve from the
packaging and connect to the desired end of the manifold.
Ensure the seal is correctly in place before tightening the
compression nut by hand on to the manifold. To ensure
the valves are securely connected to the manifold, use a
38mm spanner or wrench to tighten by a further half turn.
Remove the isolating valves (supplied separately) from the packaging
and connect to the opposite end of the manifold. As with
the air vent and drain valve, ensure the seal is correctly in
place before tightening the compression nut by hand on to
the manifold. Then, complete the connection by using a 38mm
spanner or wrench to tighten by a further half turn.
Fix the manifold horizontally in the desired position utilising
both screw holes on each bracket.
The manifold is now in position and ready to be connected
to the mains from the boiler and the under oor heating pipe
circuits. A set of self adhesive stickers are included to help
identify each circuit on the manifold. The stickers also provide
the opportunity to record the number of turns required for the
correct ow rate through each circuit (for further information
on testing and commissioning see pages 46 and 47).
62 L
80 50
A
B
C
Outlets 2 3 4 5 6 7 8
L (mm) 190 245 300 355 410 465 520
Outlets 9 10 11 12 13 14
L (mm) 575 630 685 740 795 850
Dimension 1”
A (mm) 39
B (mm) 64
C (mm) 86
CONNECTING TO HEAT SOURCE
Polypipe under floor heating systems are designed to be connected to a variety
of heat source options.
Gas and oil boilers
When connecting to any heat source it is essential that the under
oor heating manifold(s) are fed directly from the heat source with
a dedicated set of ow and return primaries, to enable total
independent hydraulic control of the under oor heating system.
Under no circumstances should this primary feed be connected
into any other heating pipework, such as radiator or domestic
hot water primary circuits.
To provide independent hydraulic control of the entire system, it is
important that the installation is designed as an ‘S Plan’ or ‘S Plan Plus’
conguration which allows for a two port zone valve to be tted to all
primary circuits and at each under oor heating manifold (see diagram).
IMPORTANT NOTE: Under no circumstances should a Polypipe
under oor heating system be connected in to a ‘Y Plan’ (ow share)
system as this will result in serious system operating problems.
To ensure that the correct operating temperatures and system ow
rates are maintained for the under oor heating system, the manifold(s)
should be tted with a manual blending valve and circulating pump
(see section ‘Water temperature controls’). However, it is the
responsibility of the designer/installer to ensure that the boiler and
system pump are capable of providing sufcient outputs in order
to meet the requirements of the primary pipework, the under oor
heating system and any other equipment installed in the system.
Typical ‘S Plan Plus’ configuration
Typical ‘S Plan Plus’ configuration via thermal store
Heat pumps
Polypipe under oor heating systems are ideal for use with heat
pump systems due to the lower operating temperatures that
are produced by this type of heat source. However, to provide
temperature limitation protection and sufcient system ow
rate for the under oor heating installation, it is recommended
to t the manual blending valve and pump pack as supplied
by Polypipe Building Products Ltd.
It is the responsibility of the system design/installer to ensure that
the heating circulation pump supplied with the heat pump,
and any associated primary pipework, is capable of providing
sufcient duty to meet the demand up to the under oor heating
manifold assembly. This also applies if a ‘buffer tank’ has been
tted to the heat pump installation.
A buffer tank or thermal store is often tted between the heat
pump and the under oor heating system. This is to provide
a sufcient quantity of stored water to feed the under oor heating
system and to ensure that the heat pump ow rates are maintained,
thereby reducing the risk of cycling. By using a buffer tank
installation there is no need to use ‘open circuits’ at the under
oor heating manifold, therefore allowing individual room control.
The Underoor Heating Manufacturers
Association (UHMA) do not recommended
that the under oor heating system be used
as an ‘open circuit’, to provide the ow rate requirement for
the heat pump installation, as this could lead to problems
with system control at a later date. For further information
regarding the installation of the system please contact the
Polypipe Technical Hotline on 01709 770000.
Solid fuel and wood burners
Under no circumstances should a Polypipe under oor heating
system be connected directly to this type of heat source.
Instead, the burner should be used to provide indirect heat via
a thermal store or similar neutraliser. The low temperature feed
from this store can then be pumped to the under oor heating
manifold, as with a heat pump installation.
Please seek specialist advice from the heat source supplier
or manufacturer before commencing the installation.