Last week we had our panel discuss STS Construction Boards and how they could be used as a superior alternative to plasterboard. This we were specifically asked about render application and STS Construction boards.

Our team, Joel, Vince, Gavin and Charlie sat down to talk about some of the typical questions we get asked [about the performance of our 12mm STS Construction Board as an external Render Carrier Board] .regarding rendering or, more specifically rending onto our 12mm STS Construction Boards.

Can I apply sand and cement render to STS Construction Boards?

Whilst our STS Construction boards gives a great bonding surface, if we asked for render its usually for timber frame buildings which are susceptible to movement (even if it’s only slight movement) which in turn can cause the render to crack. We’d recommend that a thin coat silicon based render is to be used with our boards. 

If you are looking to do a “patch-up job” our boards are fine just remember to use a render mesh around the edges.

What would be a typical build-up of a thin coat silicon render onto STS Construction board thicknesses?

You should always refer to the manufacturers guidelines. An example of the suggested build up as suggested by K-Rend can be seen below.


In the light of recent guideline changes from NHBC and LABC regarding MgO boards, can STS Construction Boards still be used for render?

Yes – STS Construction boards are a fibre cement board not and Magnesium Oxide Board. Fibre cement is made up of sand, cement, water, and organic fibres and therefore is not affected by the recent updates but is actually highly recommended for this application.

Which render manufacturers have approved and tested the STS Construction boards?

One Board. Multiple Applications.


FIRE PROTECTION: Our 12mm board has a 112 minute burn time on a single skinned wall with an A1 fire rating. Plasterboard does not hold the same 

IMPACT RESISTANT: STS Construction board is high impact to meaning it is a great solution for high traffic areas.

RECYCLABLE: STS construction board is also 100% recyclable, plasterboard isn’t.

WATER RESISTANT: Ideal partition walling in damp or wet areas. It’s also weather resistant, so can be exposed to poor weather on site during the construction phase without concern. A weather protective coating is required for permanent exposure.

We’d be happy to answer question in our Q & A session so if there is a specific topic you’d like us to discuss please reach out.