Description
The STS NoMorePly full-size 2.4 m × 1.2 m × 12 mm fibre-cement render carrier board is the storey-height substrate for timber-frame, steel-frame, and SIP facades, covering 2.88 m² per sheet at 45 kg. Euroclass A1 non-combustible, 12.46 MPa dry bending strength, and 1,650 N mean pull-through, manufactured to BS EN 12467.
Where the STS Full-Size Carrier Board Performs Best — Storey-Height UK Elevations
The 2,400 × 1,200 × 12 mm carrier board is the standard render-substrate format on UK timber-frame, steel-frame, and SIP construction, sized to cover a full storey height in a single sheet across most domestic and mid-rise wall heights. Density holds at 1.28 g/cm³, bending strength is rated 12.46 MPa dry and 12.91 MPa after warm-water saturation, and pull-through averages 1,650 N at the screw. Supplied through the Renders World rendering cement boards range, it is the format that dominates continuous wall runs where joint count drives basecoat reinforcement labour.
Read the saturated bending value carefully: 12.91 MPa after warm-water testing confirms the board does not soften when wetted by basecoat or driving rain. The 2.88 m² coverage is the structural reason this format leads full-elevation work — on a 30 m² gable, moving from half-size to full-size sheets drops joint linear metres by more than half, and that saving carries straight through to reinforcement labour.
Why Trade Specifiers Choose the Full-Size Carrier Board
- Lowest joint count per square metre in the range: 2.88 m² coverage per sheet is the practical choice for continuous stud-bay runs, where every joint becomes a mesh-embedment task — full sheets drop reinforcement labour proportionally against half-size board count.
- Euroclass A1 non-combustible: tested under EN 13501-1, EN ISO 1182, and EN ISO 1716, supporting facade specifications where the project fire strategy specifies a non-combustible carrier, subject to design verification under current Approved Document B guidance.
- Heavy-duty fixing headroom: 1,650 N mean pull-through and 840 N pull-out give capacity for direct fixing of sills, oversill brackets, and lighter trim to the board face without a separate substrate-mounted bracket detail.
- Dimensionally stable across moisture cycles: 0.16% linear variation under moisture loading keeps joints tight after basecoat, reducing the reflective-cracking risk that drives most post-handover render remediation.
- Full BS EN 12467 compliance: Category A, Class 2 MOR classification with verified freeze-thaw, heat-rain, warm-water, and soak-dry durability — the test scope NHBC and BBA-certified system specifications expect on rendered facades.
Technical Specifications — STS Full-Size Carrier Board Data Sheet Highlights
| Property | Value |
|---|---|
| Dimensions | 2,400 × 1,200 × 12 mm |
| Coverage per board | 2.88 m² |
| Board weight | 45 kg (±2% tolerance) |
| Density | 1.28 g/cm³ |
| Bending strength (dry / saturated) | 12.46 MPa / 12.91 MPa |
| Compression strength | 14.42 MPa |
| Linear variation with moisture | 0.16% |
| Thermal conductivity (λ) | 0.241 W/mK |
| Reaction to fire | Euroclass A1 — non-combustible (EN 13501-1) |
| Pull-through / pull-out (mean) | 1,650 N / 840 N |
| Water impermeability (primed face) | No damp patch after 192 hours |
| Manufacturing standard | BS EN 12467:2016 + A1:2016 (Category A, Class 2 MOR) |
| Matched fixing | STS 38 mm Ruspert-coated screws (sold separately) |
| Typical screw count per board | 30–35 on stud framing at 600 mm centres |
How to Install the Full-Size Carrier Board — Fixing, Joints, Priming
The full-size board fixes directly to timber or light-gauge steel framing ahead of any render layers, using the matched STS 38 mm Ruspert-coated screws at 200 mm perimeter centres and 300 mm in the field — roughly 30–35 screws per sheet on studs at 600 mm centres. Drive flush with the board face, since the published 1,650 N pull-through depends on the head bearing against undamaged material rather than fractured board around an over-driven head.
Leave a 3–4 mm gap between boards, fill with flexible cementitious adhesive, and embed reinforcement mesh while the adhesive is wet, overlapped per the fibreglass mesh overlap guide across every joint. Stagger joints between rows so no four boards meet at a point, then prime the full surface to equalise suction before render. For the complete worked sequence with primer selection and thin-coat finish integration, the cement boards for rendering guide covers it end to end. Within an EWI build-up, mechanical anchors back to the structural wall may also be required, and the insulation fixing accessories range supplies the matched anchors.
Installation Notes — Two-Person Handling, Joint Stagger, Fixing Headroom
For the best result, treat the 45 kg weight as the planning constraint that drives lift logistics. Pre-cut boards at ground level wherever geometry permits — a cutting station beside the scaffold loading bay turns boards over faster than carrying full sheets up to measure at height. Two-person handling on scaffold is the realistic assumption above first-lift, with a third pair of hands at scaffold level speeding placement on storey-height runs.
The 1,650 N pull-through and 840 N pull-out values let ancillary trim — oversill brackets, downpipe clips, and lighter cabinet work — fix directly into the board face rather than needing a separate bracket detail behind. That headroom matters on facades with a dense trim schedule around openings. Heavier loads such as structural rails or cladding brackets should still fix back to the framing, since the pull-through figures cover the board itself rather than load transfer into the wall structure.
How the Full-Size Board Compares to the Half-Size Format
Both formats share the same fibre-cement composition, EN 12467 mechanical class, 12 mm thickness, and Euroclass A1 fire classification — the compliance narrative is identical. The choice between them is a handling, joint-count, and cut-yield decision driven by the geometry of each area on the elevation.
| Variant | Key Spec | When to Choose |
|---|---|---|
| Full-size 2.4 × 1.2 m (this product) | 2.88 m² · 45 kg | Storey-height runs, lowest joint count |
| Half-size 1.2 × 0.8 m | 0.96 m² · 15.8 kg | Reveals, dormers, single-person handling |
On most domestic and mid-rise facades a planned mix is the most efficient ordering pattern — full sheets carry the main wall areas, half-size handles reveals and detail work where small geometry rewards less cut-waste. The same STS 38 mm screw fixes both, so the fixing schedule consolidates onto a single SKU even when the board mix splits.
Pro Tips From UK Installers Using the Full-Size Board
- Grade off-cuts at the cutting station, not the skip: off-cuts above roughly 0.4 m² are usually useful for reveal panels and sill returns — a graded off-cut stack captures that material before it is wasted and reduces the half-size board count actually needed.
- Plan scaffold lifts around the 45 kg drop: a two-board buffer at scaffold level keeps the placement crew working without runs back to ground stock, and lift sequencing planned at scaffold-design stage avoids the midway pause when board count exceeds a single lift's capacity.
- Use the pull-through headroom for trim: the 1,650 N mean value carries oversill brackets and downpipe clips straight into the board face, simplifying the trim schedule and cutting fixing-pattern coordination around openings.
- Offset joints by a clear board-width step: a half-board stagger reads as near-alignment from the elevation view, so a clear board-width offset breaks the joint line cleanly — that is the geometry reflective-crack mitigation actually depends on.
- Prime the field first, then the joints: a uniform pass across the board face equalises the bulk of the suction differential, and a second pass on taped joints brings them up to match, avoiding differential cure across the panel from a single rushed application.
Is the Full-Size Render Carrier Board Right for Your Project?
- Storey-height timber-frame or steel-frame walls: the right format — full sheets cover continuous stud-bay runs with the lowest joint count per square metre in the range.
- Fire-strategy-driven facade specifications: the Euroclass A1 classification supports build-ups where the project fire strategy specifies a non-combustible carrier, subject to design verification under current Approved Document B guidance.
- Reveals, dormers, and soffit returns: consider the half-size 1.2 × 0.8 m board — lower cut-waste on detail areas and single-person handling where lifting a 45 kg sheet at height would be awkward.
- Render finish over the carrier: the primed board accepts thin-coat build-ups directly from the Renders World premium silicone render range once basecoat and mesh are in place.
- EWI on solid masonry walls: not applicable where render goes directly onto basecoated insulation over masonry — this range suits frame construction where the carrier is part of the build-up.
FAQ — Full-Size Carrier Board Coverage, Compatibility, Ordering
How many screws are needed per board?
The typical pattern is 200 mm perimeter centres and 300 mm in the field, giving roughly 30–35 screws per 2.88 m² sheet on studs at 600 mm centres. A 250-piece box of matched STS 38 mm Ruspert-coated screws covers approximately seven full-size boards on this schedule. Always cross-reference the system designer's spacing schedule for the specific build-up.
Is the 12 mm board genuinely Class A1 non-combustible?
Yes — tested to EN 13501-1 with supporting EN ISO 1182 and EN ISO 1716 results, the board is classified Euroclass A1. That suits build-ups where the project fire strategy specifies non-combustible materials behind render, subject to design verification under current Approved Document B guidance. The classification appears on the manufacturer's A1 certificate linked below.
Do I need to prime before rendering?
Yes. A quartz-loaded primer equalises suction between the board face and the basecoated joint lines, delivering a more uniform render finish across the panel. Primed water impermeability remains intact after 192 hours of contact testing, so the surface holds its working properties across the long programme typical of storey-height work.
What can be fixed directly into the board face?
The 1,650 N mean pull-through and 840 N pull-out values support direct fixing of lighter ancillary trim — oversill brackets, downpipe clips, and light cabinet work — without a separate substrate-mounted bracket. Heavier loads such as structural rails or cladding brackets should fix back to the framing behind, since the values cover the board itself rather than load transfer into the wall structure.
Can this format be used for internal applications?
Yes. The Class A1 rating and primed water impermeability suit internal wet rooms, shower enclosures, and tile-backer work, and the 2.88 m² coverage handles wet-room walls with fewer joints than the half-size format. Tanking and waterproofing membrane requirements should be confirmed against the manufacturer's current recommendations for the specific use case.
Is the board suitable for mid-rise commercial facades?
The BS EN 12467 Category A, Class 2 MOR classification with verified freeze-thaw, heat-rain, warm-water, and soak-dry durability suits the test scope NHBC and BBA-certified system specifications expect at mid-rise scale. Project suitability rests on the system designer's full specification — fire strategy, wind-load calculations, and the certified system the board sits within — so confirm against the project specification before commitment.
Technical Documentation — STS Full-Size Carrier Board TDS and Fire Classification