Cracked Rendering

6 Aug 2009
Reaction score
United Kingdom
Hi There

First time poster - wonder if anyone can give advice on this.

I live in an 8 year-old house, still covered by NHBC's 10 year warranty. Ours is a timber-framed, brick house, covered by white rendering (sorry - not sure of material).

We're currently embarking on what I suspect will be a long-haul fight with our builder - our rendering is cracking badly, and some areas are 'bossed', across the whole house. The builder is suggesting patching the bossed areas, and filling the cracks with a rendering mastic.

My concern is that the mastic will be a temporary fix, and will need done again in the near future (once the NHBC warranty has expired), and that the patched areas will always stand out as a different colour - giving the house a patchy, spotty appearance. And finally - that with 33 cracks, and 7 separate bossed areas, chances are that more cracks will appear.

Can anyone confirm if my impression is right on this - and, if they do go ahead and patch the bossed areas, if it would make a difference if they paint the house, to give it a uniform colour (or, if indeed, the patches will weather to become the same colour).

Many thanks
Sponsored Links
Aw c'mon, let's have a photo!

So why is the rendering cracking? Is the house moving, or is the rendering not stuck? Or was the mix all wrong? Your builder will be able to tell you I'm sure.
I would try to find out what the original render system was. Then ask a technical rep from the supplier to report on the render and the reason for the cracking. If the reason is incorrect original specification or faulty application then that puts you in a much stronger position because statute of limitations is delayed where the the original defect was not visible.

Thanks for your reply. I think I've attached an image here - this is one of the 33 cracks - not sure if you can make it out - this is an area to the side of the front window - the crack runs from the corner, for about 6 inches into the top centre of the damp patch. The photo is taken just after a rain shower.

The bossed areas are literally falling off the wall, but I don't have any images at the minute - I can get some.

As for the material of the render - the builder is proving pretty uncommunicative and uncooperative - his original suggestion was to do nothing, till the NHBC surveyor said action would need to be taken.

Thanks again - hope this illuminates.
Sponsored Links
Thanks John, that's a good tip, and I'll try to pursue this (3 of my neighbours has to have the rendering completely removed and re-applied 2 years ago - one of them might have this info).

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local