Rendering (George Wimpey)Wimpey Bannerbrook

[DEAN1972COV]

I have a problem with cracks in the rendering on the side of my house which is only 11 months old.When i spoke to the builder(George Wimpey) he tried to blag me it was natural shrinkage.When i told him i was thinking of selling the property and that it would come up in a surveyors report he then told me he would monitor it.The 2 things i'd like to know are 1.Will the cracks cause moredamage to the property with water getting in etc? 2.Does this problem come under sructual problems?

[Tony]

Hi Dean,

It is unlikely that this is caused by structural problems, but it could be. You would need an expert opinion to establish this. However, you are still within the snagging period assuming that you have an NHBC warranty in place.

Could you describe the cracks in a bit more detail? Are the other properties on the estate suffering from the same problem?

Needless to say once water starts getting into these in the winter they are only going to get worse.

Tony

[DEAN1972COV]

The cracks in the rendering go from the edge of the two bottom floor windows to the ground.0ne is about 2mm wide and the other is about 4mm wide you can also see where it is about to crack directly under the window.I have looked at other houses on the estate and have seen no problem with the rendering on other properties but these have been built by other builders not George Wimpey.Thank you very much for your time Tony

[Tony]

Rendering
Rendering on walls should be reasonably
consistent in texture, fi nish and colour.
Commentary
• Rendering should, where possible,
be viewed in natural daylight from a
distance of 10m.
• Some minor cracking and crazing is
likely to occur but should not be such as
to affect its performance.
• Some patches and daywork joints may
be visible but should not be unduly
obtrusive.

2mm will affect performance in the winter the cracks they are taking about here are hairline ones. Don't be fobbed off by the builder

Tony

http://www.nhbc.co.uk/NHBCPublicatio...d,15912,en.pdf

[Caxton]

Originally Posted by DEAN1972COV

The cracks in the rendering go from the edge of the two bottom floor windows to the ground.0ne is about 2mm wide and the other is about 4mm wide you can also see where it is about to crack directly under the window.I have looked at other houses on the estate and have seen no problem with the rendering on other properties but these have been built by other builders not George Wimpey.Thank you very much for your time Tony

Without seeing it, it is difficult to be definitive but the cracking may be caused by shrinkage of the background. Today most often renders are applied to concrete blockwork. Blockwork shrinks (the amount depending on the type of block and its moisture content) and this sets up stresses which concentrate around openings and cause the kind of cracks you describe if suitable precautions, such as movement joints and/or bed joint reinforcement are not incorporated. Most renders, if traditional two-coat, are about 16 - 20mm thick. If you insert a thin tool into the crack, such as a nail, does it go all all the way in or only the depth of the render?