Hi - I'm a newbie here, so apologies if I'm asking daft questions or posting in the wrong place....

I've got a semi-detached house with a painted rendered wall facing south. The render is covering red brick, and the walls are cavity walls. We've been in the house for about 13 years, and the render was quite new at the time we moved in. Now there are cracks appearing in the render - mostly horizontal ones. I'm concerned that this may be the wall ties failing, and in addition, I'd like to insulate the wall as the house is very cold in winter. Obviously I don't want to put cavity wall insulation in before sorting out the cracking problem - especially if it is a problem with the wall ties.

Anyone got any advice? Or could recommend a trustworthy insulation/wall tie company to take a look. I'm worried that if I ask companies to take a look at a possible wall tie problem they will soon tell me there is one whether that's true or not.

We are in Farnham in Surrey.

Thanks in advance for any advice.
Chris

I have no idea about surrey but RSI seem to be pretty good and may well do that area,
most cavity wall insulation companies provide wall tie fixing as well as other remedial services.

http://www.rsinsulation.co.uk/index.shtml

_________________
- Dave
http://www.pamperhouse.net
http://www.invertedcircle.co.uk

Thanks Root

From their website, it looks like RSI do wall ties too. Definitely worth a call to them. You'd rate them as trustworthy would you? i.e. if my wall ties are ok they won't try to pull the wool over my eyes?!

Cheers
Chris

Hi,

Yes, horizontal cracking does sound like wall ties - but not always.

I am a wall tie specialist based in Yorkshire, so not any good for you. However, you could try the following trade association web sites who will have members near you:

http://bit.ly/jr4Z1P

or

http://bit.ly/jKRmKl

Whatever you do, do not have insulation installed until this is resolved - it is much more expensive to instal a wall tie system after insulation and the work would invalidate any guarantees the insulator gives you.

I always provide digital images of the ties as seen through a boroscope to help clients and give credability, but this may not be available near you. Get at least two opinions and ask them for a wall tie survey in accordance with BRE digest 401. This has a visual grading of corroding wall ties table in it and should make sure the findings are less subjective.

Hope this helps.

Look under wall ties on my blog for more info: http://bit.ly/mzTLLT

All useful information Dryrot Please read the rules regarding self promotion.
Mod 2

Is the horizontal cracking a uniform 450mm centres up the height of the wall ? where it is usual to lay in the ties when building a cavity ?

I agree do a boroscope survey of the cavity. To save costs and be certain you are not being hoodwinked you can hire these out and do it yourself initially to gauge an idea if it is the wall tie problem.

Have you also considered any timbers being embedded in the wall at these crack lines (ie: some differential movement) OR any steelwork, just thinking of the wider causes here....any photos ?