Forest Xtend 2.5 Manual

XTEND 2.5 GUIDE BOOK
(2.5x2.5M)
Missing something?
Call our aftersales team on
0333 777 7089
Need more information?
Call our technical team on
0333 321 3142
Visit our website for more
information
www.forestgarden.co.uk
Forest Garden, Oak Drive, Hartlebury Trading Estate, Hartlebury, Worcestershire, DY10 4JB
Thank you for purchasing your Xtend Garden Building from Forest Garden. Simply follow these step by step
instructions and our top tips for a straightforward assembly. If you have any questions or need advice, our
friendly team is here to help.
ISSUE: 0221
FIXING PACK CODE: XTENDFP

Please keep plastic bags and small parts away from children.
‘Fixtures & Fittings’ Box Contents
All of our Xtend garden buildings are constructed in the same way. They simply come with slightly different
components depending on the size you have purchased. Don’t worry if your ‘xtures and ttings’ box
contains many extra xings at the end of the build (you haven’t missed a bit!). We have sent you a generic
xtures and ttings box to suit the Xtend garden building collection.
6.7 x 150mm Screws
QTY: 40
6.7 x 125mm Screws
QTY: 90
7.5 x 112mm Screws
QTY: 35
5 x 80mm Screws
QTY: 280
4 x 50mm Screws
QTY: 220
4 x 35mm Screws
QTY: 430
10 x 10mm Staples
QTY: 1000
750ml B3 Fill & Fix
Expanding Foam
QTY: 3
‘Star’ Drill Bit
QTY: 1
310ml Translucent
Silicone
QTY: 1
1-6mm Glazing Packers
QTY: 10 of Each
1.6 x 30mm Panel Pins
QTY: 155
300ml Anthracite Grey
Silicone (7016)
QTY: 1
1
2
3
4
5
6
7
8
9
10
11
12
13
1
2
3
4
5
6
7
8
12mm Wood Plugs
QTY: 100 14
10
11
12
13
14
Drill & 2-6.5mm
Drill Bits
Tools Required
Assembly is relatively straightforward if you follow these step by step instructions. All screw holes should
be pre-drilled to avoid splitting the timber.
We recommend using the following tools (not supplied):
Rubber Mallet /
Hammer
Tape Measure Spirit Level Ladder
Foam Gun Sharp Knife
(Stanley Knife)
Hand Saw/Hand
Circular Saw
Heavy Duty
Staple Gun
Sander
REMINDER
Always pre-drill before
screwing.
IMPORTANT
Assembly requires 2+ adults
& 2+ person lifts at all times.
Please keep plastic bags and small parts away from children.
2

Health and Safety
We strongly recommend that PPE (Personal Protective Equipment) is used throughout your Xtend garden
building assembly to ensure you are protected from any potential health and safety risks. Do not exempt
yourself from wearing PPE even if the job ‘only takes a few minutes.’ Use any guidance stated on the
supplied xings and where you feel it is applicable to use PPE as part of your step by step assembly.
Chemical Information
Due to the high quantity of products we have supplied and recommended to use, we strongly
recommend checking all the chemical information, application, shelf-life, storage, cautions and health
and safety sections which will be listed on the back of each product. For further information, these
branded products can be found online where they will have PDF technical sheets to access. If you have any
further concerns or queries, you can contact the suppliers/manufacturers for extra information.
Do not leave empty containers where residue could be harmful to children, animals or the
environment. Replace lids and move any containers to a central disposal point in accordance with local
regulations. Do not pierce cans. In the event of a spillage, remove all sources of ignition, ventilate the
area, and remove people from conned areas. Spillages should be mopped up immediately with an inert
absorbent material such as sand.
B3 Fill & Fix Expanding Foam Extra Information
B3 Fill & Fix Expanding Foam is just like many other types of expanding foam. It is vital that you know how
to set up and use the expanding foam correctly for an easy application during your assembly. As this is a
generic xing pack and we do not supply any tools, the expanding foam does require a foam gun.
Preparation & Application
Before applying your expanding foam, you need to ensure that the surfaces to
be bonded are rm, clean, dry and free from dust, grease or contaminants that
may hinder effective adhesion. All of the construction components that will be
in contact with the expanding foam must be properly prepared as described
above. It is advisable to have a can of ‘Foam Cleaner’ to hand.
Ensure your foam gun is set up correctly and shake your expanding foam can
vigorously prior to use. Use the gun with the can uppermost and as close to
vertical as possible. Otherwise, you will have poor foam discharge during your
application. Also, take care not to overll joints when applying to your base kit
panels. Fresh foam spills can be removed straightaway or, if left to harden, they
can be removed with a scraper or knife.
Cleaning The Nozzle
As the expanding foam will be in use over the 2 days of the Xtend garden building assembly, it is best
to keep the nozzle of your foam gun clean enough to prevent any blocking of the product when next
coming to use it. Excess foam can be removed whilst still wet using ‘Bond It Foam Cleaner’ or ‘Bond It
Multi-wipes.’ Once the expanding foam has cured, it can only be removed by scraper. Store and transport
upright in cool, dry conditions between 5 and 25°C. 3

Before You Start
Assembly Guide
Do not attempt assembly of your building until you have checked the ‘component list’ at the back of this guide book
to ensure all parts are present. You must notify our Technical Helpline of any missing or damaged components within
14 days of receipt of the building.
In the unlikely event of any problems, issues or for any questions, please contact our Technical Helpline on
0333 777 7089. Before you call, please make a note of any parts that may be damaged or missing.
Please refer to your xtures and ttings box for supplied screws, expanding foam and nails. Tools for erecting and
preserving the building are not supplied as part of the purchase and are listed on page 6 for a guide.
Guarantees are limited to the replacement of incorrect or damaged materials. Your statutory rights
are unaffected.
Building your garden room is relatively straightforward for anyone with a good standard of DIY or building
experience. In general, it does not require any special skills, but it will require a logical approach and will sometimes
require some general carpentry. If you have any doubts as to your ability, you should contact Forest Garden and
arrange for a professional team to assemble the building for you.
Be aware of any raised ground surrounding the site of the garden room as this may cause water to drain onto the
slab base or under the Xtend building. Building the base correctly is very important – cutting corners on this part of
the project will potentially make assembly difcult, and jeopardise the longevity of your garden room.
For more information on building your base, please refer to the Base Preparation section mentioned in this guide
book.
It is strongly recommended that you build your garden room in dry conditions for the best building experience
and results.
In addition to this written guide, we also have a supplementary ‘how to’ video guide which can be viewed at
forestgarden.co.uk if you would like any extra guidance during your step by step build.
The step by step assembly instructions are partly generic. The oor plans provided are specic to your Xtend
garden building but most of the imagery is generic, as the build is relatively the same for all Xtend garden buildings.
The main difference is the quantity of components provided.
XTEND GARDEN BUILDING INFORMATION & ASSEMBLY GUIDE 4

BEARERS & FLOOR PANELS
Lay the bearers down and spread them out roughly
ready to position the oor panels on top.
Ensure the panel is ush to the edges of the rst
bearer. Ensure the oor panel on the bearers are
level using a spirit level as a guide.
33
55
1122
Pre-drill for every process before securing with
screws. Pre-drill 5 holes along the edge of the rst
oor panel. Do not screw in the other side at the
moment.
Using 125mm screws, screw through the oor
panel into the oor bearer beneath. Repeat the
process for the 4 other screws. Ensure each screw
is countersunk.
Place the second oor panel (A) onto the middle
and end bearers. Ensure the panel is positioned
half way on the middle bearer.
Place the rst oor panel (B) on ush to the edge
of the rst bearer and halfway onto the second
bearer. Place the black underside of the oor panel
on top of the bearers as shown above.
44
66
5

BEARERS & FLOOR PANELS
Using a rubber mallet, knock the second panel into
the rst for a tight t.
Using 4 x 35mm screws, pre-drill and screw where
the adjoining panels intersect. This will secure the
oor panels together.
99
1111
A
B
7788
This step does not apply for the Xtend2.5 build.
You only have 2 oors. Use the layout on step 11a
as a guide.
Once happy that all panels are in the correct
position, further secure with 5 x 125mm screws
along the outer edge of the second panel.
Screw positions are shown in the diagram above.
The larger screw heads are 125mm and the smaller
ones are 35mm. The fully constructed oor should
now be fully secured and ush to the edges of all
the oor bearers. Use a spirit level to ensure the
oor is level before continuing with the build.
Knock on the front and back of the second panel
to ensure it is ush on both edges to the rst panel
and oor bearers.
1010
11a11a
6

FLOOR PANEL CAPS & OSB SHEETS
The components provided will be labelled
according to the components list at the back of
this guide book.
11b11b
Pre-drill and use 4 x 125mm screws ensuring
each screw goes into the bearer beneath. Screw
35mm screws between the 125mm screws. Repeat
process for the other oor capping.
1313
This step does not apply for the Xtend2.5 build.
You only have two OSB sheets.
1717
Using 35mm screws, screw 3 across the top and 5
down the sides of each OSB sheet. Screw along
the sides rst.
1515
Insert and knock the oor capping (AL) into place
using a rubber mallet. Ensure it is ush to all
edges.
1212
Position OSB oor sheets (AG) on top of the oor
panels one at a time. Ensure they are ush to all
edges and screw into the corners to keep secure.
1414
Some pieces may be oversized. If this is the case,
saw off any excess once the sheets are screwed in
place to create a ush nish.
1818
Screw the central screws into place, resulting in 3
in a row. This will result in 15 x 35mm screws per
OSB sheet.
1616
7

APPLYING DPC TO YOUR BASE
Start to unwrap the DPC roll and choose a starting
point on the base’s outer face. Ensure it covers half
of the bearers and staple into place.
Once fully wrapped around the base, overlap the
starting point and staple into place.
2121
2323
1919 2020
Using a Stanley knife, cut the DPC at the corner to
create 2 pieces to easily fold onto the OSB sheets
and staple into place.
Continue folding the overhang and corners of DPC
onto the OSB sheets as you make your way around
and staple into place.
The nal result is shown above.
Continue to wrap around the base. We suggest
one person unwraps while the other follows
behind stapling the DPC into place.
a
2222
2424
8

FLOOR PLATES
As part of your assembly pack, you will have been
provided with an OSB offcut to use as an 11mm
guide when positioning the oor plates.
2525
Repeat the process with the front Floor Plate (AL).
Ensure the one end is ush to the side and 11mm
from the front edge.
2727
Your side Floor Plates (AK) will t between your
front and back plates. Ensure 11mm from the outer
edge and 11mm at each end. Once happy with the
position, pre-drill and screw into place using 4 x
125mm screws.
3131
Use the measurement to mark onto the front oor
plate, starting from the end of the timber. Repeat
the process at the opposite end.
2929
Starting with the back Floor Plate (AL), ensure it
is ush at each end and use the 11mm offcut to
ensure an 11mm space from the base’s back edge
all the way along. Pre-drill and screw 4 x 125mm
screws along the timber.
2626
Pre-drill and use 4 x 125mm screws for the front
Floor Plate (AL). Apply 2 x 125mm screws per end.
Measure the width of your Front Panel (O) from
side to side on the OSB sheet.
2828
The nal result is shown above.
3232
Cut and remove the central part of the front oor
plate. This will remove the excess timber from your
door opening. Your front panel will sit ush end to
end of the front oor plate.
3030
a
9

WALL PANELS
SIDE PANEL 2 (H) SIDE PANEL 2 (H)
SIDE PANEL 1 (G) SIDE PANEL 1 (G)
FRONT PANEL
(O)
SIDE PANEL 4 (J)
FRONT PANEL
(O)
LINTEL INSERT (R)
SPLINE (Q)
INBETWEEN
YOUR WALL
PANELS
WINDOW PANEL
(N)
WINDOW PANEL
(N1)
WINDOW INSERT
(AA)
Place onto the oor plate and the wall panel will sit
ush to the edge.
3535
Next, start to build your walls. Each wall panel is
labelled according to the layout shown above and
the components list at the back of this guide.
3333
In the left hand corner, the wall panel will be ush
to the edge and the oor plate as shown above.
3636
Begin the build at the left back corner, starting
with Side Panel 2 (H). Insert the expanding foam
provided into the bottom groove.
3434
WALL PANEL LAYOUT
10

WALL PANELS
Working in the back left corner, add the expanding
foam into the side groove of the Side Panel 1 (G)
and butt it up against Side Panel 2 (H). Have one
person holding onto the wall panel to prevent
movement.
3737
There will be smaller Spline Panels (Q) that will
be in between the grooves of some panels. Add
expanding foam into each groove of the spline
panel and apply them according to the wall panel
layout. Secure with 5 x 35mm screws.
3939
Pre-drill and screw through the Back Panel (H) Side
Panel (G) using 3 x 150mm screws (top, middle
and bottom).
4343
Add expanding foam into the inner side groove
and into the bottom groove of the second Back
Panel (H) and knock into place to complete the
back wall.
4141
Pre-drill and, using the star drill bit provided in
your xing box, screw through the back into the
side wall panel using 3 x 150mm screws (top,
middle and bottom).
3838
Slide the Spline (Q) into the First Panel (H). Please
note that Xtend2.5 only has 2 x back panels.
4040
Install the right hand side panels as shown above
(N), adding the expanding foam into the bottom
grooves. Place and knock into the other side panel.
4444
Repeat the same process for the right hand corner
(G). Add foam and knock into place. Ensure the
panel is ush to all edges as mentioned and shown
above.
4242
11

WALL PANELS
Install the Window Panel (N1) as shown above,
leaving the provided space for the window insert.
This is labelled on the layout.
4545
Position the screw roughly 45mm from the outer
edge. Pre-drill and screw through the front into
the side wall panel using 3 x 150mm screws (top,
middle and bottom).
4747
Slide and knock into place.
5151
Use 35mm screws to secure the window insert into
place by screwing from both outside and inside of
each wall panel into the window insert. This will
use a total of 8 x 35mm screws.
4949
Install the Front Panel (O) and butt up against the
front side wall panel installed in the previous step.
Ensure all edges are ush.
4646
Knock the Window Insert (AA) into the the space
between Window Panel (N) and Window Panel
(N1). Ensure the top is ush.
4848
Install the other Front Panel (O). Pre-drill and screw
through the front, into the side panel using 3 x
150mm screws (top, middle and bottom).
5252
Install the last Side Panel 4 (J). Apply expanding
foam into the bottom groove.
5050
12

WALL PANELS
Insert the Lintel (R) and knock into place. Ensure it
is ush to the top of the front panels.
Once all of the wall panels are up, begin to secure
each wall panel to the oor plate underneath. Use
3 x 35mm screws per panel externally.
5555
5757
5353 5454
Repeat the process from the inside, using 3 x
35mm screws per panel once again.
Where spline panels have been used to join side
panels, use 5 x 35mm screws to secure from top
to bottom along the connection. Do not screw
directly into the adjoining line. Repeat this process
for every adjoining panel.
Starting with the front panels, apply expanding
foam in the top groove, ready to add the wall
plates.
Use 35mm screws to secure the lintel in place by
screwing from both outside and inside of each
wall panel into the lintel. This will use a total of 8 x
35mm screws.
5656
5858
13

WALL PLATES & FIRRINGS
Insert the Front Wall Plate (AL), knocking into
place. Expect this to be tight tting. Ensure it is
ush to the top and ends.
5959
Further secure each of the wall plates with 3 x
35mm screws externally and 3 x 35mm internally,
through the side panels into the plate, between
the 125mm screws.
6363
Use 2 x 125mm screws to secure the thicker end of
the rring component.
6565
Insert the Side Wall Plate (AK). Pre-drill and secure
with 4 x 125mm screws. Repeat the process for the
other side wall plate and the back wall plate.
6262
Pre-drill and secure with 4 x 125mm screws.
Repeat the same process for the Back Wall Plate
(AL).
6060
Apply expanding foam to the groove of one of the
side panels.
6161
Use 2 x 35mm screws to secure the thinner end of
the rring component. Repeat this process for the
other rring.
6666
Position the Firring (AB) and butt up against the
front panel.
6464
14

ROOF PANELS
Lift up the rst Roof Panel (V). Ensure at least 3
adults help carefully lift up the roof panels as they
are heavy.
6767
Xtend2.5 only consists of two roof panels. This
step does not apply to your build.
7171
Xtend2.5 only consists of two roof panels. This
step does not apply to your build.
7373
Xtend2.5 only consists of two roof panels. This
step does not apply to your build.
7070
Use the spirit level to ensure the top OSB sheet of
the roof panel is ush with the back edge of the
wall panel. Top Tip - Use the Canopy T&G Panel
(BJ) as a reference for the correct overhang size
at the front.
6868
Use 4 x 150mm screws along the side edge.
6969
Lift up the second Roof Panel (U) and apply
expanding foam into the inner groove as shown
above.
7474
Xtend2.5 only consists of two roof panels. This
step does not apply to your build.
7272
15

ROOF PANELS & ROOF PANEL CAPS
Knock further into place to allow the roof panel to
be as ush as possible to the wall face.
7575
Use expanding foam in the groove of all roof
panels.
7979
Use expanding foam and knock the Front Roof
Panel Cap (AQ) into place. Ensure all faces are
ush to the front and side edges.
8181
If there is a 2-5mm overhang on the side, don’t
worry. This will not affect the rest of the build.
7878
Pre-drill and secure 5 x 35mm screws where the
adjoining panels intersect.
7676
Repeat the same process as the rst roof panel
using 4 x 150mm screws along the edge to fully
secure the roof. Then secure the second roof
panel’s other side edge with 2 x 150mm screws at
each corner.
7777
Use 4 x 80mm screws into the front roof panel cap.
Use 3 x 35mm screws between the 80mm screws
to fully secure.
8282
Insert the Back Roof Panel Cap (AQ). Use 4 x
125mm screws through the back roof panel cap
and into the wall panel’s. Use 3 x 35mm screws
between the 125mm screws to fully secure.
8080
16

BREATHABLE MEMBRANE
Begin to unwrap the breathable membrane.
Position the membrane 45mm from the ground.
8383
Once the starting point has been overlapped, cut
off the excess and staple the end of the material
into place.
8787
Add additional staples to keep the membrane in
place. Be careful not to staple into the door and
window gaps.
8989
Continue unwrapping the membrane, pulling
tightly and stapling into place.
8686
Starting with the bottom section, pull the
membrane tightly and staple into place.
8484
Then wrap the excess around the corner and
staple the starting point into place.
8585
There will be a slight gap at the front and on the
sides due to the angle of the roof.
9090
Repeat the same process for the top half of the
building. Ensure the starting point is ush to the
top of the back wall panels.
8888
17

BREATHABLE MEMBRANE
Using a Stanley knife, remove the excess from the
door section, using the walls as a guide to ensure
it is cut straight.
9191
Use the excess membrane to cover the angle on
the side panels.
9595
Remove the excess from each side of the roof
overhang.
9797
Staple into place and remove the excess from the
door section.
9494
Repeat the same process to remove the excess
from the window section.
9292
Using the excess membrane, cover the front ush
up to the roof.
9393
The nal result is shown above. You do not need to
add membrane to the canopy / the roof overhang.
9898
Fold onto the roof, stapling into place.
9696
18

EXTERNAL T&G CLADDING
T&G SIDE PANEL 1
(BM)
T&G SIDE PANEL 2
(BN)
T&G SIDE PANEL 3
(BA)
T&G SIDE PANEL 4
(BB)
T&G SIDE PANEL 4
(BB)
T&G WINDOW
PANEL
(BC)
T&G FRONT PANEL
(AU)
T&G FRONT PANEL
(AU)
T&G LINTEL (BL) & T&G KICK PLATE (BK)
Begin applying the T&G Back Panel (BN).
9999
Repeat the same process for the second Back
Panel (BM). Use a rubber mallet to softly knock the
second back panel into the rst, so the T&G Panels
interlock.
101101
Use 6 x 80mm screws to secure each cladded
panel (3 screws down each side). Screw through
the batten on the panel and into the wall behind.
Leave the screws slightly out in case of adjustment.
102102
At each side, there will be a slight overhang of
the T&G board. The batten’s edge underneath,
attached to the panel should be ush to the end.
Use the 45 x 28mm batten as a guide to prvide a
45mm space from the ground.
100100
T&G CLADDING LAYOUT
19

EXTERNAL T&G CLADDING
Continue onto the side panels (BB). Knock the rst
panel in place and ensure it is butted up against
the back panel overhang.
103103
Using 3 x 80mm screws, screw the rearmost side of
the T&G Panel (BA) into place into place.
107107
Repeat the same process on the opposite side
(BB). Start at the back and butt up against the back
panel’s T&G board. Screw into place.
109109
Use a rubber mallet to softly knock the second
Side Panel (BA) into the rst, so the T&G panels
interlock.
106106
Use 6 x 80mm screws per panel. Ensure you use
3 x 80mm screws down each side of the cladded
panel.
104104
Ensure the cladded panels are 45mm off the
ground. If you are using the batten as a guide,
slightly lift up the secured panel to ensure it is
carefully removed to prevent any damage.
105105
Install the Window Opening Panel (BC) ensuring it
is ush to all edges. If not aligned properly, this will
cause issues during the window installation.
110110
The batten and the T&G board will overhang at
the front, as indicated on the layout shown above.
Pre-drill ready for when you need to secure with 3
x 80mm screws into the front panel.
108108
20