fixing guidelines

FIXING
GUIDELINES
FOR TIMBER AND
COMPOSITE DECKING
FIXING GUIDELINES FOR
TIMBER AND COMPOSITE DECKING
This guide will help you when choosing the type of fixings to use, where to place the fixings and other
practical recommendations – depending on the type of deck board you are using.
For further information on all aspects of decking, visit: www.tda.org.uk
01. SPACING BETWEEN JOISTS
02. MINIMUM GAP AROUND PERIMETER
When spacing your joist structure,
the maximum gap between joists
(from centre to centre) should be
no more than 400mm.
For timber decking:
When decking up to buildings or door
sills, install the joist structure and deck
boards so they are clear of the building
by at least 10mm and always below the
damp course.
For Composite decking:
Leave at least 30mm.
NOTE: SPACING RECOMMENDED IS FOR DOMESTIC OR LIGHT COMMERCIAL USE, IF IN ANY
DOUBT SEEK FURTHER PROFESSIONAL HELP. ALTERNATIVELY VISIT WWW.TDA.ORG.UK
This will allow for any expansion.
03. AVOID WATER POOLING
This is down to your planning and preparation
of the joist perimeter structure. Using a simple spacer
acts as an effective guide and a 2mm fall in gradient of
the joist in every metre is sufficient to ensure the rain
water runs away and prevents any pooling, reducing
maintenance too.
FOR EXAMPLE
4(m) x 2 = 8(mm) FALL
NOTE: THE FALL SHOULD RUN IN LINE WITH THE GROOVES ON
THE DECK BOARDS TO AID RUN OFF.
04. DECK BOARD FIXINGS
05. PILOT HOLES - TIMBER DECKING
For timber decking:
4.5 x 63mm
Stainless steel or coated
deck screws.
For timber decking:
Drilling a pilot hole before screwing
down is recommended, alternatively
use a self-countersinking screw.
For Composite
decking:
Use secret fix clips
(screws included).
NOTE:
THIS DOES NOT APPLY TO COMPOSITE.
SEE POINT 07.
06. FIXING DOWN TIMBER DECK BOARDS
Fix the boards down securely with two fixings per joist.
Screws will provide a more secure fixing than nails.
To avoid the potential for the timber to split:
A. Position the fixing at least15mm
from end of deck board.
B. Position the fixing at least 20mm
from the edge of the deck board.
NOTE: THIS DOES NOT APPLY TO COMPOSITE.
02
DECK BOARD FIXING GUIDELINES –
FOR TIMBER AND COMPOSITE DECKING
A
B
07. FIXING DOWN COMPOSITE DECK BOARDS
Fix the boards down securely with one secret fixing
clip per joist.
Position the clip in the groove of deck board.
Position the board together with the clip in the centre
of the joist and screw down.
Add the next deck board – sliding the fixing clip into
the groove of the board.
08 SPACING BETWEEN DECK BOARDS
For timber decking:
Ensure there is a minimum gap of 5-6mm between each deck board.
For Composite decking:
Ensure there is a minimum gap of 10mm between each deck board.
This will be largely governed by the secret fixing clip.
09. JOINING TWO BOARDS IN A RUN
For timber decking:
When joining two cut deck boards together in a
run, fix with screws 15mm from the end of each
board, at an angle to ensure secure fixing into the
joists below.
NOTE: WHERE MORE THAN TWO BOARDS ARE FIXED IN A RUN, A
MINIMUM 6mm GAP IS REQUIRED FOR ALL OUR TIMBER BOARDS.
NOTE: COMPOSITE REQUIRES A MINIMUM 10mm GAP.
10. PROTECTING YOUR TIMBER DECK
Ensure any cut timber or drilled holes are treated with a suitable,
high-quality timber preservative. A thorough coat of treatment
only takes a moment and will prolong the life of the deck.
This procedure is often a condition reflected in the product’s
guarantee, so is worth following.
FOR TIMBER AND COMPOSITE DECKING
–
DECK BOARD FIXING GUIDELINES
03
A CHOICE OF 6 DECK BOARD OPTIONS - 5 TIMBER AND 1 COMPOSITE
DECK BOARD INSTALLATION SUMMARY
MAX JOIST
CENTRES
SPACING
BETWEEN BOARDS
GAP AROUND
PERIMETER
FALL
FIXING TYPE
PILOT HOLES
FIXING POINTS
Classic Softwood
400
5-6mm
10mm
2 in 1000mm
4.5 x 63mm Stainless Steel
or coated deck screws
Recommended
2 per joist
through face
of board
ThermoWood®
400
5-6mm
10mm
2 in 1000mm
4.5 x 63mm Stainless Steel
or coated deck screws
Yes
2 per joist
through face
of board
Hardwood
400
5-6mm
10mm
2 in 1000mm
4.5 x 63mm Stainless Steel
or coated deck screws
Yes
2 per joist
through face
of board
Min 15mm
from end and
Min 20mm
from edge
FIXING DETAIL
GrasseDeck PRO®/ 400
GrasseDeck®
5-6mm
10mm
2 in 1000mm
4.5 x 63mm Stainless Steel
or coated deck screws
Recommended
2 per joist
through face
of board
WalkSure™
400
5-6mm
10mm
2 in 1000mm
4.5 x 63mm Stainless Steel
or coated deck screws
Recommended
2 per joist
through face
of board
Composite
400
10mm
30mm
2 in 1000mm
Fixing clip with
screws supplied
Not applicable
1 secret fixing
clip per joist
1 per joist
Using secret
fixing clip
NOTE: WHERE MORE THAN TWO BOARDS ARE FIXED IN A RUN, A MIN 6mm GAP IS REQUIRED FOR ALL OUR TIMBER BOARDS. NOTE: COMPOSITE REQUIRES A 10mm GAP.
FURTHER INFORMATION
For further information on all aspects of decking including:
• Painting your deck
• Deck maintenance
• Other recommendations
Visit: www.tda.org.uk
FOR FURTHER DETAILS ON HOW TO BUILD A DECK
VIEW OUR LATEST BROCHURE
Telephone: +44 (0)800 00 44 44
MW0097 SEP 12
Email: [email protected]
www.metsawood.co.uk
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