Installing Assured Hollow Composite Joists

Installing Composite Joists To Support Composite Decking

Assured Hollow Composite Joists require a solid concrete foundation to fix to. We advice creating a decline of 1% – 1.5% running away from a property acting as a drainage slope. Drainage holes or gutters can be placed in the concrete foundations if required.​

When installing composite joists ensure the area is clear and free of any obstacles including any cables and pipes.​

Laying The Composite Joists

Measure and cut composite joists where required.

Lay the composite joists into position leaving 300mm max intervals between each composite joist centre to centre. Leave 10mm expansion gaps close to a property and at joist butt joins.

Fix composite joists into place by drilling holes through the middle groove of each composite joist and into the solid foundation. Start at 80mm approx and then at 500mm approx intervals.
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​Double joist where deck boards meet at butt joins allowing a 3mm gap between composite joists.