STS Construction Board. One Board – Multiple Applications. 

Our STS Construction boards are available in 6mm, 9mm and 12mm depths. These boards are serious over achievers – Not only is it Impervious to moisture, it’s the preferred substrate to carry large, heavy wall tiles. Plus its impact resistant, providing a tough, long lasting walling material that gives you a solid feel to the touch. Securing fixings, such as towel rails, are no problem and it comes with an A1 fire rating so it’s ideal to line out fireplaces before tiling and installing log burners. It’s a versatile board that suits lots of applications, including for external use as a render board. Both the 9mm and 12mm STS Construction Boards are available in two sizes, full and half size.

6mm STS Construction Board

Suitable for internal and external use. Impervious to moisture and A1 Fire Rated. The 6mm STS Construction board has numerous applications including over boarding timber floors prior to tiling as well as cavity closure, eaves boards, under canopies, or as a ceiling board where fire rating is required. The A1 fire resistant board means that your structure will be safer in the event of a fire outbreak.

9mm STS Construction Board

Primarily designed to overboard floors and walls in place of plywood, helping to eliminate problems caused through warping and movement. It is completely unaffected by moisture and has a lateral strength equivalent to 18mm plywood. This means that 9mm boards are ideal for over-boarding solid walls prior to tiling and they are the first board to come with a lifetime guarantee.

12mm STS Construction Board

A first choice for wet areas. Impervious to moisture, it’s the preferred substrate to carry large, heavy wall tiles. The 12mm STS Construction board is impact resistant, providing a tough, long lasting walling material with a solid feel to touch. Securing fixings, such as towel rails, are no problem and it comes with an A1 fire rating, so it’s ideal to line out fireplaces before tiling and installing log burners. It’s a versatile board that suits lots of applications, including for external use as a render board. Available in two sizes, small and large size.

Water Resistant Board: Ideal in wet spaces
Suitable for External Render
Strong: Can support bathroom fixings
Internal render wall board
A1 fire rated board: ideal stove backer
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Specification
FAQs
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STS Construction Boards Technical Data

6mm STS Construction Board

Dimensions Measurement Test Standard
Length 2400mm BS EN 12467:2016 + A1:2016
Width 1200mm
Thickness 6mm (tolerence 6.66%)
Weight 28kg

9mm STS Construction Board

Dimensions Measurement Test Standard
Length 2400mm 1200mm BS EN 12467:2016 + A1:2016
Width 1200mm 900mm
Thickness 9mm (tolerence 6.66%)
Weight 15kg 42kg

12mm STS Construction Board

Dimensions Measurement Test Standard
Length 1200mm 1200mm
Width 2400mm 800mm
Thickness 12mm (tolerence 6.66%) BS EN 12467:2016 + A1:2016
Weight 47kg 15.86kg
Performance
Density 1.28g/cm3 BS EN 12467:2016 + A1:2016
Linear Variation (Change in moisture) 0.16%
Bending Strength (Dry) 12.46 MPa @ max force 1563 N BS EN 12467:2016 + A1:2016
Bending Strength (saturated in warm water) 12.91 MPa @ max force 1563 N BS EN 12467:2016 + A1:2016
Water impermeability (unprimed) No water formation after 24 hours Damp patch covers tested area BS EN 12467:2016 + A1:2016
Water impermeability (Primed) No water formation after 24 hours No damp patch in tested area after 192 hours
Reaction to fire A1/A1fl En ISO 1182 & EN ISO 1716
Testing
Pull through testing  Mean result: 1650 (Newtons)
 Pull out testing   Mean result: 840 (Newtons)

 

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FAQs

When wet, do STS Construction Boards lose any strength, plus, when they dry, do they recover all their original strength?

STS 12mm Construction Boards will lose some strength when wet. Multiple tests have been carried out which included a pull through test at control conditions when the boards were dry and a pull though test after the boards were immersed in 23°C water for 7 days. There was a slight loss in strength when the boards were tested after immersion, however, when they reverted to their dry state, almost all strength had been retained.

What is the maximum length of time an STS 12mm Construction Board can be fitted and then exposed to weather prior to rendering?

We recommend rendering the fitted STS 12mm Construction Board as soon as conditions allow, although these boards can be left fully exposed for up to 3 months prior to rendering. Pay particular attention to preparation of boards to receive render base coat when boards have been exposed for a prolonged period. You must ensure boards have fully dried and that the surface is cleaned of any debris, dust and magnesium salts that may have been attracted to the surface.

How does STS advise on render preparation?

Specific guidance for preparation of boards to receive render varies slightly from each render supplier, so STS recommends following your preferred render supplier’s guidance to ensure validity of warranty.

What side of STS Construction Boards do I render on to?

Use either side. Both accept render easily.

Can I put sand and cement onto STS Construction Boards?

Sand and cement renders have been used successfully numerous times with STS Construction Board, but due to the lack of dedicated testing and quality assurance STS cannot recommend this application for use. The decision of the compatibility is the sole responsibility of the render applicator.

Do STS Construction Boards need to be hard fixed or can they be dot and dabbed?

STS always recommends mechanical fixings in addition to dot and dab onto solid surfaces.

Can STS 12mm Construction Boards be used in place of plasterboard?

Yes, STS Construction Boards have far superior properties in comparison with plasterboard such as fire resistance, impact strength, breathability performance and durability to damp.

Can STS 12mm Construction Boards support wall fittings?

Yes, STS 12mm Construction Boards will support fittings such as toilet roll holders, shower curtain rails, vanity mirrors, shelves and pictures when appropriate fixings are used. Larger, heavier fittings such as grab rails and cabinets must always be fitted into supporting stud work.

Can STS Construction Boards be used behind a wood burning stove?

Yes, STS Construction Boards are A1 fire rated and an ideal board to use behind wood burning stoves. Please consult the stove manufacturer to confirm the appropriate distance required between the stove and board.

Can STS Construction Boards be painted and plastered?

Yes. Before applying paint or plaster, STS Construction Boards require priming on face and edges with SBR Primer.

Do STS Construction Boards require priming before applying tile adhesive?

Priming STS Construction Boards is always best practice before applying tile adhesive. Tests have proved the bond between tile adhesive and 12mm Construction Boards was significantly strengthened when primer was applied.

What mechanical fixings do I use?

Use STS TORX screws for timber or metal stud work. These should be readily available from all local merchants. Fix at 300mm centres.

How should STS Construction Boards be stored?

STS boards are delivered on clearly labelled pallets, wrapped and packaged to prevent weathering and edge damage. They should be stored flat on a pallet, in dry conditions indoors. Boards should not be lent upright for long periods of time and whilst stored, moisture should not be allowed to drip on to or infiltrate between stored sheets to prevent surface staining. Larger sized boards should be always lifted by 2 people and carried on their edge, so to avoid unnecessary damage.