Small Plastic Joist
Small Plastic Joist
SKU: NT-ACC-SF-PLJ-SNot sure which colour? Order free samples · Questions? Speak to an expert
Product benefits
Why choose Grainex® composite
Up to 25-Year Warranty
The most comprehensive warranty available on UK composite products. Residential and commercial cover included.
Zero Maintenance
Never sand, paint, stain or treat. A simple wash with soapy water is all that's ever needed.
Anti-Slip Both Sides
Embossed grip texture on both board faces provides safe footing in wet conditions year-round.
Fade & Stain Resistant
UV-stabilised composite won't fade, splinter or rot. Resists mould, algae, oil and wine stains.
Weatherproof
Handles British frost, rain and UV without warping, cracking or delaminating.
Eco-Responsible
Made from recycled wood fibres and reclaimed plastics. FSC-certified. A sustainable timber alternative.
About this product
Small Plastic Joists are a compact, versatile subframe solution for composite decking. These 50mm x 50mm recycled plastic joists are ideal for smaller decking projects and repairs where a lightweight, rot-proof joist is required. The small profile allows for flexible installation in tight spaces.
Exclusively handpicked excellence, manufactured and distributed by NeoTimber®
Technical Specifications
| Product name | Small Plastic Joist |
| SKU | NT-ACC-SF-PLJ-S |
| Material | Co-extruded composite (WPC) — recycled wood fibre & HDPE |
| Board length | 3.6m |
| Board width | 145mm |
| Board thickness | 25mm |
| Weight per board | approx. 6.2kg |
| Coverage per board | approx. 0.52m² |
| Core construction | Hollow twin-wall |
| Surface finish | Co-extruded cap both sides, anti-slip emboss |
| Minimum joist spacing | 400mm perpendicular / 300mm diagonal |
| Fire classification | Euroclass E |
| Residential warranty | Up to 25 years |
| Commercial warranty | 10 years |
Compare the Full Range
Find the right grade for your project and budget.
| Feature | Lite | Essential | Classic | Advanced | Deluxe |
|---|---|---|---|---|---|
| Price (from) | £19/board | £23/board | £28/board | £32/board | £38/board |
| Core | Single wall | Single wall | Hollow twin | Solid | Solid + cap |
| Co-extrusion | ✕ | ✕ | ✓ | ✓ | Premium |
| Colours available | 4 | 4 | 4 | 8 | 8 |
| Fade resistance | Good | Good | Very Good | Excellent | Superior |
| Residential warranty | 10 years | 15 years | 20 years | 25 years | 25 years |
| Best for | Budget builds | Standard decks | Mid-range | Quality finish | Premium projects |
Installation Guide
A professional-finish composite deck can be installed by a competent DIYer over a weekend.
Plan and measure your area
Mark out your deck area and calculate the total square meterage. Add 10–15% for cuts and wastage.
Prepare the sub-frame
Install pressure-treated C24 timber or aluminium joists on a firm, level base. Joist spacing must not exceed 400mm centre-to-centre for perpendicular boards, 300mm for diagonal laying.
Lay the first board
Start at the most visible edge or against the house wall. Allow a 5mm gap from any fixed structure. Use the supplied starter clips — slot into the board's groove and screw into each joist.
Continue laying boards
Press each board firmly into the previous clips, then add middle clips to the exposed groove. Check alignment every 3–4 boards. Stagger butt joints by at least 600mm across rows.
Cut and finish edges
Use a fine-tooth circular saw with the cut side face-up. Seal cut ends if the deck will be exposed to standing water at that edge.
Add trims and fascia
Finish exposed edges with matching fascia, corner trims, and skirting. Fit edge boards using stainless screws colour-matched to your boards.
