When is settlement subsidence?

Spit62500

Hi,

I have a new single storey extension which was built last October and plastered just before Christmas. The walls are constructed as two rows of solid block with insulation between sitting on a strip foundation.

A crack has appeared beneath a window over the last two months - a crack runs up from the floor and is about 6 inches long. A second crack runs down from the window sill and stops about an inch away from the first crack. A matching crack is visible on the outer wall also. Both cracks are just slightly bigger than hairline.

Is it too early to worry about this? Is it just settlement or is this something to worry about?

Any advice much appreciated....

muffler

These type of questions pop up every now and then and by and large you will find that it is generally a settlement issue. However it is just simply impossible to say what it is for sure without a first hand inspection and really and truly pics aren't that helpful.

Apart from that I have to emphasise that posts in response to the query are purely personal opinions only and are not to be taken as being in any way conclusive as to the reason for the problem or the solution thereto.

As usual the best advice that can be offered in these situations is to get a structural engineer.

Im not suggesting that the question shouldn't have been asked or indeed personal opinions offered but I am just taking the opportunity to remind people of the forum's policies.

Kashkai

Every house, no matter if its a total new build or an extension will throw up settlement cracks as the building compresses after construction.

However Muffler is right that you shouldn't just take any Joe Soap's 2 cents worth. An Engineer will carry out an inspection and will report to you on the likely cause of the crack. Most charge in the region of €350 - €500 for this service. Lot of money but worth it for the peace of mind. I'd give it another couple of months to see if it gets any worse. Take photos at regular intervals so you can document the progress of the cracks.

Spit62500

Thanks for the advice. I'll keep an eye on it and if it progresses, I'll get an engineer in a couple of months.

mad m

You can also buy sudsidence kits to check your problem..I think in kit you get a couple of sheet of small thin glass with holes on them. You nail glass onto wall either side of crack and over a time if the glass cracks its a sign of subsidence.

Think kits are around €40,and last time I heard you could probably get them from Brooksthomas.

muffler

Glass will probably crack when being nailed to wall

Spit62500

mad m wrote:

You can also buy sudsidence kits to check your problem..I think in kit you get a couple of sheet of small thin glass with holes on them. You nail glass onto wall either side of crack and over a time if the glass cracks its a sign of subsidence.

Think kits are around €40,and last time I heard you could probably get them from Brooksthomas.

Thanks - I'm picking up my wooden floor from Brooks next Saturday - I'll ask them when I'm in.

shakeydude

I think that they are called tell tales. Put them up, take a few pics and then come back in a few months

twenty8

Generally speaking the vertical cracks are normally ok - but keep an eye out for horizontal cracks!

muffler

twenty8 wrote:

Generally speaking the vertical cracks are normally ok - but keep an eye out for horizontal cracks!

Final answer?