Forest Xtend 4.0 Manual

XTEND 4.0 GUIDE BOOK
(4.0x3.0M)
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: 0121
FIXING PACK CODE: XTENDFP

‘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  xings 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 your follow these step by step instructions. We recommend
getting everything aligned properly before screwing together and that 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+ man lifts at all times.
Please keep plastic bags and small parts away from children.
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 build 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 your
xings supplied 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 of 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 specic branded products can be found online and they will have PDF technical sheets ready at
hand to access. If you have any further concerns or queries, you can contact the suppliers/manufacturer’s
for extra information.
Do not leave empty containers where residue could be harmful to children, animals or the
environment. Replace lids and remove any containers to a central disposal point in accordance with local
regulations. Do not pierce can. In the event of spillage remove all sources of ignition, ventilate the area,
remove people from conned areas. Material 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 must be rm, clean, dry and free from dust, grease or contaminants
to prevent any hinderance for the adhesive to work effectively. All of the
construction components that will be in contact with the expanding foam must
be properly prepared prior to foam application. It is advisable to have a ‘Foam
Clear’ at 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 as a result, you will have poor foam discharge
during your application. Also, take care on 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 mechanically 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 on 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 mechanically. 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 xings 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 a professional team to assemble the building for you.
You should also pay special attention to the possibility of surrounding raised ground draining onto the slab or under
your garden room. 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 a lot of the imagery is generic, as the build is relatively the same for all Xtend garden buildings.
The only main differences are the quantities 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 around the edges to the
rst bearer. Ensure the oor panels 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 (E) onto the middle
bearers. Ensure the panel is positioned half way on
both bearers.
Place the rst oor panel (D) on top of the two
bearers and position it half way onto the second
bearer. The black side covered in tar will be 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. Repeat the same process for
the third panel (E).
99
1111
DE
EF
7788
Place the forth  oor panel (F), knock into the
second panel and ensure it sits  ush on the  nal
 oor bearer. Repeat the process using 35mm
screws in between the second and third panels.
Once happy that all panels are in the correct
positions, further secure with 5 x 125mm screws
along the third panel edges and the  rst panels
outer edge into the bearers beneath.
Screw positions are shown in the diagram above.
The larger screw heads are 125mm and the smaller
ones are 35mm. The  nal  oor result should now
be fully secured and  ush around all faces of the
bearers beneath. Use 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
accordingly to the components list, at the back of
this guide book.
Pre-drill and use 4 x 125mm screws and ensure
each screw goes into the bearer beneath. Screw
35mm screws in between the 125mm screws.
Repeat process for the other oor capping.
1313
Ensure that all OSB sheets t proportionally onto
your oor.
1717
Using 35mm screws, screw 3 across the top and 5
down the sides of each OSB sheet. Screw along
the edges rst.
1515
Insert and knock the oor capping (AN) into place
using a rubber mallet. Ensure it is ush to all
edges.
1212
Apply OSB oor sheets (AD & AE) on top of the
SIPS 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 the excess off after the piece is screwed into
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
11b11b
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 in place.
The nal result is shown above.
Continue to wrap around the base. We suggest
one person unwraps and the other will follow
behind, stapling in place.
a
2222
2424
8

FLOOR PLATES
As part of your assembly pack, you will have been
provided with an off cut of OSB to use as an 11mm
guide when positioning the oor plates.
2525
Repeat the process with the front oor plate (AP).
Ensure the one end is ush to the side and 11mm
from the front edge.
2727
Repeat the process on the other side oor plate
(AN) and screw into place.
3131
Mark and cut off the excess timber from the front
oor plate. This will remove any timber from your
door opening.
2929
Starting with the back oor plate (AP), ensure
it’s ush end to end and provide 11mm spacing
from the bases’ back edge. Pre-drill and screw 4 x
125mm screws along the timber.
2626
Pre-drill and use 4 x 125mm screws for the front
oor plate (AP) Apply 2 x 125mm screws per end.
Measure out your front panel (P) and ensure your
front panel is placed ush to the edge.
2828
The nal result is shown above.
3232
Your side oor plates (AN) will t in 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.
3030
a
9

WALL PANELS
SIDE PANEL 4 (J) SIDE PANEL 2 (K) SIDE PANEL 2 (K) SIDE
PANEL 3 (L)
SIDE PANEL 4
(M)
SIDE PANEL 4
(M)
SIDE PANEL 2
(K)
SIDE PANEL 2
(K)
SIDE PANEL 4
(J)
WINDOW PANEL
(N)
WINDOW PANEL
(N1)
WINDOW INSERT
(AA)
FRONT PANEL
(P)
FRONT PANEL
(P)
LINTEL INSERT (T)
SPLINE (Q)
INBETWEEN
YOUR WALL
PANELS
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 accordingly 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 4 (J). Insert the expanding foam
provided into the bottom groove.
3434
WALL PANEL LAYOUT
10

WALL PANELS
Add the expanding foam into the side groove of
the Side Panel 4 (M) in the left back corner and
butt it up against the rst wall panel. 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 accordingly to the wall panel
layout. Secure with 5 x 35mm screws.
3939
Pre-drill and screw through the back panel (L) into
the side wall panel (M) using 3 x 150mm screws
(top, middle and bottom). Continue on each side
with side panel 2 (k).
4343
Repeat the same process on the last back panel (L)
and knock into place.
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
Add expanding foam into the inner side groove
and into the bottom groove of the second back
panel (K). Slide on the oor plate and knock into
place. Repeat the process for the third back panel
(K).
4040
Apply to 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 (K).
4444
Repeat the same process for the right hand corner
(M). Add foam and knock into place. Ensure the
panel is ush to all edges as mentioned and shown
above.
4242
11

WALL PANELS
Apply the side wall 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
Position the screws on the wall panels OSB and
screw into the window insert batten behind.
Secure into place using 4 x 35mm screws internally
and externally, 2 x 35mm screws each side of the
window insert.
4949
Apply the front wall panel (P) and butt up against
the front side wall panel just secured. Ensure all
edges are ush.
4646
Knock the window insert (AA) into the section
provided. Ensure the top is ush.
4848
Apply the other front wall panel (P). Pre-drill and
screw through the front into the side wall panel
using 3 x 150mm screws (top, middle and bottom).
5252
Apply the last left hand side panel (J). Apply
expanding foam into the bottom groove.
5050
12

WALL PANELS
Insert the lintel piece (T) and knock into place.
Ensure it is ush on the top.
Once all of the wall panels are up, begin to secure
each wall panel to the oor plate underneath. Use
3 x 35mm per panel externally.
5555
5757
5353 5454
Repeat the process, using 3 x 35mm per panel
internally.
Internally position the screws each side of the
adjoining split line. Use 5 x 35mm screws for each
side of adjoining panels with the spline panel
inside from top to bottom. Repeat this process for
every adjoining panel.
Use the expanding foam into the top groove,
ready for the wall plates. Start at the front.
Position the screws on the Lintels OSB and screw
into the wall batten behind. Secure into place
using 4 x 35mm screws internally and externally, 2
x 35mm screws each side of the lintel insert.
5656
5858
13

WALL PLATES & FIRRINGS
Insert the front wall plate (AP), knocking into place.
Expect this to be tight tting. Ensure it is ush to
the top and ends.
5959
Further secure each all of the wall plates with 3 x
35mm screws externally and internally, through the
OSB into the plate, in between the 125mm screws.
6363
Use 2 x 125mm screws to secure the component
within the thicker section.
6565
Insert the side wall plate (AN). Pre-drill and secure
with 4 x 125mm screws. Repeat the process for
the other side wall plate and back wall plate with
expanding foam and 125mm screws.
6262
Pre-drill and secure with 4 x 125mm screws.
Repeat the same process for the back wall plate
(AP).
6060
Apply expanding foam to the side panels groove.
6161
Use 2 x 35mm screws to secure the component
within the thinner section. Repeat this process on
the opposite side.
6666
Position the rring (AC) and butt up against the
front wall panel.
6464
14

ROOF PANELS
Lift up the rst roof panel (X). Ensure at least
3 adults can lift up the roof panels carefully as
they are heavy. Measure the overall width for the
roof and allow 2mm each side in case of a slight
oversize in roof panels.
6767
Use expanding foam in the groove of the roof
panel and knock into place. Ensure the roof is ush
to the front and back of the rst roof panel.
7171
Secure the second roof panel to the front and back
panels. Use 2 x 150mm screws at the back and 2 x
150mm screws at the front. Repeat this process for
the third roof panel (Y).
7373
Lift and position the second roof panel (Y).
7070
Position the back of the roof panel. Using the spirit
level as a guide, the top OSB sheet on the roof
panel needs to be ush to the back edge. Use 4 x
150mm screws along the edge.
6868
Use the spirit guide as a reference to screw
through the roof panel into the side wall beneath.
Top Tip - Use the canopy T&G panel (BD) as a
reference for the correct overhang size.
6969
Lift up the nal roof panel (Z) and apply expanding
foam into the inner groove as shown above.
7474
Pre-drill and screw 5 x 35mm screws, where the
adjoining panels intersect. This will secure the roof
panels together. Then secure the rst roof panels
corners with 2 x 150mm screws.
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 roof panels groove
across all 3 panels.
7979
Use expanding foam and knock the roof panel cap
(AS) into place. Repeat the same process. Ensure
they are ush to all edges.
8181
If there is a 2-5mm overhang, don’t worry this
won’t affect the rest of the build.
7878
Pre-drill and screw 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 third roof panels
opposite corners with 2 x 150mm screws.
7777
Use 4 x 80mm screws into the panel cap. Use 3
x 35mm screws, in between the 80mm screws to
fully secure.
8282
Insert the roof panel cap (AS). Use 4 x 125mm
screws through the panel cap and into the wall
panel. Use 3 x 35mm screws, in 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 warp 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 roof overhang excess.
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
(AX)
T&G SIDE PANEL 2
(AZ)
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
(BE)
T&G FRONT PANEL
(BE)
T&G LINTEL & T&G KICK PLATE
(BG) & (BF)
T&G SIDE PANEL 6
(BI)
T&G SIDE PANEL 5
(BH)
T&G SIDE PANEL 5
(BH)
Begin applying the T&G cladding at the back (AZ).
9999
Repeat the same process for the second back
panel (BI). Softly knock the second back panel into
the  rst, so the T&G interlocks the panels together.
Use a rubber mallet for a softer application.
Repeat the same process for the (AX) T&G panel.
101101
Use 6 x 80mm screws on each panel, 3 x 80mm
down each side of the cladded panel, through the
batten and into the wall panel 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 battens edge underneath should
be  ush to the end. Use the 45 x 28mm batten as
a guide to leave 45mm 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 one side into
place.
107107
Repeat the same process on the opposite side (BB
& BH). Start at the back and butt up against the
back panels T&G board. Screw into place.
109109
Apply the next side panels (BH & BA). Softly knock
the second side panel (BH) into the rst, so the
T&G interlocks the panels together. Use a rubber
mallet for a softer application. Repeat the same
process for the (BA) T&G panel.
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
Ensure the opening of the cladding is ush around
all edges to the window opening provided (BC). 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, as these 3 x 80mm screws will go
into the front panel.
108108
20