Possible Purchase, Question 1

[Penners]

Mrs P and I have found a house that we're thinking of buying. But there are a couple of things about it that I would love to get some advice on, please, from you building experts.

I must first come clean and admit that it's not a period property. But it does have a very traditional, East Anglian cottagey look to it (OK, I'll come clean - it's a pastiche ). It was built 8 years ago, it's of block masonry cavity wall construction, with an external cement render.

My first question concerns some hairline cracks that are apparent in a few places - sample pictures below (I've enhanced the contrast to make the cracks show up). They mainly exist in places related to doors, windows and so on. There doesn't appear to be any displacement of the cracks, and they appear only on the outer wall. There are no matching cracks inside the building, and no apparent sign of such cracks inside being patched up.

Would these worry you, or do you think they're just a bit of settlement in a fairly recently constructed building?

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View attachment 1

 

[skier-hughes]

:evil: Be gone with you, heathen.................



The cracks wouldn't worry me as such, but they would still be a source of water ingress between the render and brick, which may long term cause damage and other problems, such as part of the render falling off maybe :?:

 

[Andrew Bodenham]

Cement rendering seems to be a finish used by builders to ensure lots of future work for builders. The idea of having a continuous sheet of hard mortar lying against a wall (alright, stuck on in a few places) is a very poor engineering solution in my opinion. How does the render accomodate thermal movement, i.e. when the sun gets on one bit and heats it up more than another bit, or on a cold night following a warm day when the outer skin cools and shrinks faster than the underlying blockwork? Seems to me that cracking is inevitable, and it will occur at stress points like the corners of apertures etc. See your pics for details.

The solution? Hack it off and start again, repeat every few years. Maybe a lime render would perform better - but there my experience runs dry.

Hopefully others will be along soon with more optimistic assessments.

 

[jocelyn plummer]

Oh crumbs, I hope our replies don't put you off completely------it's bad enough trying to buy something as it is.
Is there still a 10 year guarentee on it?

 

[Pford75]

Firstly, congratulations on finding something which you might want to buy!

In my limited experience as a builder (saturday job as a lad), I do recall the gentleman whose business it was insisting that an external render and driveway were both fitted with expansion joints. Basically the render is divided into sections with rubberised(?) dividers. At the time this was explained to me as "big sheets of conrete or cement will crack without expansion joints".

I can't vouch for the accuracy, but the existence of the products on the market seems to indicate that this is a recognised problem. Not sure i'd go to the hassle of hacking it off and starting again...may just be a case of ensuring the painted surface remains sound.

 

[Penners]

No, there's no guarantee on the house. It was built by a builder for his son, who is now selling it. For that reason, I'm hoping that he'll have made a special effort to do a decent job.

I do agree that any and all cracks need to be properly sorted out, to prevent moisture ingress, but I'm afraid I draw the line at hacking it all off and starting again with lime (you are, of course, right Andrew, but age and finances dictate otherwise!). However, it's reassuring to know that you feel the cracks aren't an indication of anything serious.

Many thanks for your thoughts.

 

[jocelyn plummer]

That sounds like a good build, I am sure it will be fine as it is a 'one off'.

There is a good article in the October '008 edition of Period Living, entitled 'Rain, rain go away' by Douglas kent,page 146. which might be of interest to you.
Good excuse to browse the shelves in WH Smith!

 

[Penners]

Thanks, Joss.