Calcium silicate brick construction - is this a problem?

Better_Days

My surveyor has told me that the property we are in the process of purchasing is constructed of calcium silicate bricks which are brittle and can cause cracking. Some repairs have been made. I haven't got his report yet but I wanted some background info as I've not come across these bricks before. When viewing the house I thought they were just light coloured ordinary bricks.:o

Haven't been able to find much online other than this sort of brickwork is more prone to cracking. Has anyone come across these bricks and do they affect the value of the property? Would rendering help?

My surveyor is good and will chat with me after I get the report tomorrow, but didn't want to wait until Tuesday to find out more.

Jonbvn

I'm a civil/structural engineer. IMHO, this is not a problem at all. Such bricks are not used much in the UK but are common elsewhere in Europe.

Apparently, Battersea Power station was built using these bricks.

Better_Days

Thanks Jonbvn, that's very helpful.

Well Battersea Power Station has been around for a while!

There isn't really a lot to be found other than the basics about this type of brick. One website states use of this sort of brick is common in Sweden, presumably for its thermal properties. For anyone who is interested this page gives brief descriptions of the different sort of bricks
http://www.greenspec.co.uk/bricks.php
and notes that along with BPS, the RIBA building in Portland Place is also built of calcium silicate bricks.

My surveyor has noted some repairs have been done, I think we will have to consider the extent of those repairs and the likelyhood further cracks developing.

teneighty

Calcium Silicate and all similar bricks are well known for shrinkage. That is what causes the cracking and not because they are brittle. There is nothing to be done to prevent it, rendering will just crack with the bricks. Cutting in flexible movement joints can tidy up the cracked brickwork but this is quite expensive if done properly.

Better_Days

Thanks teneighty.

Is the cracking an ongoing process throughout the life of the brick, or is it more of a problem initially and then settles down? The house we are buying was built in the early 1980's.

heathmt

Hi,

We have just had a lender refuse our mortgage based on the calcium silicate bricks. we are not aware of any cracking and the property was built in the 70s. Would appreciate advice on whether this should be a deal breaker on us buying the property or if other lenders will turn us down on this basis.

Thanks