Skip to main content

Ready to hire?

Post your job in minutes, browse real reviews and choose who to speak to.Post a job

Need some tips or advice?

Ask a question
Plastering & Rendering

Removing render from thermal blockwork

Anonymous user 07/03/2024 - 2.30 PM

We are having new windows and some re- rendering. The window installer surveyor has discovered that the walls are built with thermal blocks on the exterior walls, not breeze locks, and then rendered. He has advised that we have the walls re rendered prior to window installation as the plasterer may need to add mesh to the thermal blocks to ensure the render adheres properly. My concerns are how will the thermal blocks stand up to having the render removed?

Are you a tradesperson and able to answer this question?

Log in

4 Answers

Anonymous user

If the existing render isn't too thick and is in good condition and stable with minimal signs of damage then I’d advise having a thin coat silicone render system over the existing render. You can cause too much damage to the substrate by hacking off existing render. Even more so to thermalite blockwork.
Answered7 February 2024
8

South West Render Systems LTD

Rating: 5 out of 5
Bristol
If there was a problem with adhesion due to the thermalite blocks it will come of with ease. But as PlasRend previously said, if it’s solid and not too thick then rendering over it is absolutely fine. We do this all the time and a decent renderer will be able to make that decision and advise you on which products to use in either case.
Answered9 February 2024
1

ProEffectSprayForce Limited

Rating: 5 out of 5
Mitcham
Render removal from thermal blockwork is a characteristic and straightforward task with the right method. Yet, it can be a delicate operation. Render removal needs to be done carefully to prevent thermal blocks above from being affected. Depending on the type of render and how well it applies to the blocks, various techniques like scraping, pressure washing, or chemical-based treatments may be applied. Working intentionally and slowly is essential to reducing any harm that may occur.
Answered10 February 2024
0

London Finishing Services

Rating: 4.7 out of 5
Maida Hill, London
It would make more sense to install the windows first and then you would know what is need to be repaired after the the installation of windows otherwise you may be removing render unnecessary. And would may have to repairs ouround you newly installed windows creating additional cost ... you can then assess what is needed to be done with the breeze blocks / thermal blocks which are the same .
Answered25 February 2024
0