Composite Decking Installation Tips

Thursday, June 25, 2015

While it is not too difficult to install a wood composite deck, installing it correctly will ensure that it not only looks great it will last many years without giving you any hassles.

Having been involved with building and construction for over 30 years we have certainly picked up a few tips regarding decking installations.

Not using enough clips.

We recommend using 21 of our standard plastic clips with screws for each square metre. Where two boards but up against each other we suggest that each board has their own clip at the join and do not share the clip.

Adequate Joist spacing.

The joist spacing (the beams the decking shall sit on) we recommend that your joist spacing be no more than a maximum of 350mm apart centre to centre.

Water Drainage.

When installing a composite deck you should make sure that you have a very slight slope in the overall deck so that the water can drain otherwise you will have large puddles on your deck that won’t evaporate.

Allowing for expansion.

 You must allow a minimum of 1 mm per linear metre for expansion and contraction over the length of the board – in other words if you had two 5.8metre long boards butting up against each other, you would allow 3mm on either end of each board, so this would give you a gap of 12mm where the two boards join. Another tip is to run a breaker board perpendicular to the rest every 5.8m.

When installing your L-shaped skirting that covers the edge of your deck the hole you drill for the screw should be 1mm bigger than the screw to allow for expansion and contraction.

Raising the fascia off the ground.

One of the most common problems is the fascia board running directly into the ground. This almost guarantees future problems as the fascia board will be damaged by weed eaters or water damage. To correct this we suggest you raise the fascia slightly off the ground and alternatively also install a small concrete curb just below it. 

Staggering your boards. 

Even though 4Everdeck synthetic decking boards are supplied in 5.8m lengths on a large deck you can still have a row of joins, we prefer to see the boards staggered, so that the joins are not all in the same line. This is purely from an aesthetic perspective and has nothing to do with the quality of the installation. 

Incorrect joist size.

It is very easy for an installer to save money and time by not using a large enough joist in the substructure. To ensure that your deck has an adequate substructure and will not move or sag once your composite decking is installed we recommend that you use a large enough joist that will be relatively stiff and not be springy when you walk on it.

Contact us today to discuss your decking project. -

 Find Us on