Composite Decking Installation Guide
Subframe
Composite Decking needs joist support every 300 mm and must be raised above the ground at least 30 mm but ideally 100 mm to allow for airflow under the decking
When building your subframe and installing your decking ensure you allow for-
Board size – check the length & width of your boards
Spacing in between your boards ( T-clips 6 mm SS Clips 3 mm)
Spacing at the end of every board and your end to ends (This is extremely important as composite decking expands in heat and contracts in cold.)
Ensure your noggins are in place for joining boards
If using bullnosed boards to create a boarder add extra joists / noggins on the left and right and also allow for the lip of the bullnosed edge to protrude over the fascia boards.
Use weed block on the ground to help prevent weeds growing up through your decking
If using a timber subframe use decking joist tape on the top to stop rot and moisture-because the tape is black it also means the spaces are hardly seen.
Installing Boards
There are many types of composite decking and for most of them the shade of colour will vary to create a natural look. Shuffle in the variants as you install so they will look fabulous from installation , through the weathering process and lifetime.
Starter Clips
Use starter clips when you do not have another board at the other side to join to -ie -if starting from a wall and for bullnosed boards on your left and right sides
Place the starter clip flat side down and screw to secure to joist minimum every 300 mm on the frame and each end of board (minimum 20 mm from the end) When all the necessary starter clips are in place push the board into position making sure the hook on the clip goes into the channel profile on the side of the board. Position the deck board tight against the starter clips.
Installing boards with T Clips.
Loosely screw your T clips against the bottom lip on the front side of the deck board into every joist, push enough to ensure the board is straight and just tight enough to keep the board in place. Push another deck board tightly against the front T clips and attach T clips against the bottom lip on the front side of the new deck board, then fully tighten the previous row. Add another deck board and repeat the process, until the end of the deck. Make sure you have clips at every joist and all board ends have gaps and 2 x clips.
Installing boards with SS Clips (Stainless Steel Clips)
Slip the 2 x pronged side of the clip under and into the bottom lip of the channel of the front side of the deck board and secure by using a minimum 20 mm screw. Repeat on every joist pushing the board forward enough to ensure the board is straight and firm enough to keep the board in place. Push your next deck board into the clips you have just secured so the new board channel slots into the clip. Add another row of clips and keep repeating the process until complete.
Make sure you have clips at every joist and all board ends have expansion extension gaps and 2 x clips.
Bullnosed Boards
Position your board onto the border of your subframe. Ensure you are allowing for expansion and contraction and for a lip over the edge of your frame. If you are also installing fascia boards you will need to allow for a lip that will protrude over the fascia board.
Ensure these are positioned exactly as you want them fitted.
For left and right sides : Mark out your line along the channelled side of the bullnosed boards so you know where to secure your starter clips. Remove board then secure your starter clips along that line ,at least every 500 mm and every board end.
Position board again and then draw a line on the underside of the bullnose edge so that you know where to position your L Braces. Remove board, flip over and screw the L braces onto the line at least every 500 mm and at each board end. For the mitred ends ensure your end brace is as close to the end as possible to ensure it wont lift over time.
Position your board and secure with screws through the hole of the L Brace on the face of the subframe.
Front face : You don’t need starter clips for the front bullnose because you will already have a row of T clips or SS clips for the board to be pushed on so you will just need to position the board and then draw a line on the underside of the bullnose edge so that you know where to position your L Braces. Remove board, flip over and screw the L braces onto the line at least every 400 mm and at each board end. For the mitred ends ensure your end brace is as close to the end as possible to ensure it won’t lift over time.
Position your board and secure with screws through the hole of the L Brace on the face of the subframe.If you need more than one bullnosed board along the front we advise that you install a long length in the middle and have shorter lengths towards the sides.
Fascia Board
Drill pilot holes then create oval shape holes ( to allow for expansion and contraction ) every metre and 10 to 20 mm from each end. Position board and use coloured pan head screws through these holes to secure onto the face of the subframe.
If you are using deck boards as fascia boards you can either slot caps into the ends of the boards or mitre the ends.
Edge Covers
Edge Covers can be used to cover any external 90 degree profile Cut to size with square ends or mitred ends Check sizes are correct by laying in position, if good then remove trim. Run a small bead of exterior grade adhesive down the centre of the backside of the trim but not too much that it squeezes out, then carefully position the trim. We do also advise that you first drill pilot holes then create oval shape holes ( to allow for expansion and contraction ) every metre and 30 mm from each end. Position and use coloured pan head screws through these holes to secure onto the face of the subframe as an added measure.