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?

Plastering & Rendering

External rendering cracks - what to do?

Anonymous user 06/10/2025 - 8.23 AM

Our external wall (first floor side of an extension) was rendered five years ago using polymer type render. It is now cracked all along - it’s like 10 metres long. I think the cement boards are a bit bowed. The problem might be the cement board installation, or a number of potential factors. I know the best long term solution is to take off existing render, cement boards and have it done by an expert. However this is going to cost a fortune. I don’t believe water is getting in. The render is cracked but not falling off. It doesn’t look great but I could live with a time limited repair. Any suggestions?

Are you a tradesperson and able to answer this question?

2 Answers

PAUL CRYAN

Rating: 5 out of 5

Harrow

Re render over the existing render with a thin coat silicone render system done by a pro. It may work and would be much cheaper than stripping of the existing backing boards

Answered4 October 2025

CB Plastering

Rating: 5 out of 5

Liverpool

Were the cement boards staggered or just rail roaded straight across this could be why there is a crack could be following the joint of cement boards! Depends how far you want to go to get the repair done as you could go over with a thin coat system but if the problem is with cement boards then it really needs to be removed and problem solved before doing it again to prevent same thing happening again could be lucky and it might not crack for a couple of years could be unlucky and the old render could come loose and bring new with it!

Answered9 October 2025