Shop composite decking joists UK — 3m & 3.6m framework battens, recycled plastic posts and rot-proof subframe boards for a long-lasting deck base from yumiHome. Composite Decking Joists & Framework
Common questions about composite decking joists, framework and subframe boards from yumiHome.
Composite decking joists are the structural battens and rails that form your deck subframe — the base your boards fix to. Ours are made from durable recycled materials that resist rot, moisture and insect damage better than untreated timber, giving you a long-lasting composite deck framing system for UK gardens and patios.
For composite decking boards, joists are typically spaced at 400mm centres (centre to centre) along the deck. Closer spacing may be needed for heavy use areas or specific board types — always follow our installation guides and allow for a slight fall away from the house for drainage.
Yes — every deck needs a solid subframe. Composite joists for decking provide stable, level support for your boards and help prevent bounce or movement over time. Browse our composite decking boards once your framework is planned, and add fixing clips and screws for a complete system.
Yes. Composite framework joists are a popular alternative to pressure-treated softwood because they will not rot, warp or attract insects in the same way. They are lightweight, easy to cut and ideal for low-maintenance decks — especially in damp UK climates or raised installations where timber can deteriorate faster.
We stock 3m and 3.6m composite joist battens, recycled plastic rails/battens, 50×100mm recycled plastic joists, and square support posts in 80mm and 100mm profiles (3m length). Use the product grid above to compare sizes for your deck layout and post supports.
Recycled plastic rails/battens start from £15, 3m composite joist battens from £16.19 and 3.6m battens from £17.19. Larger 50×100mm joists and support posts are priced individually on this page — from £44.95 for joists and £56.99 for posts. Trade account customers can access installer pricing.
Ground-level decks on a concrete base may only need joists and battens. Raised decks and balustrade runs usually need support posts too — we stock 80mm and 100mm square recycled plastic posts in 3m lengths. For handrails, see our balustrade kits; for a finished edge, browse fascia boards.
Beyond joists and posts you will need composite decking boards, clips or screws, and optionally fascia, trim and balustrade. Order a free decking sample to compare board colours before you buy.
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