This week in the Examiner, Kieran McCarthy of KMC Homes provides advice for fixing cracks in the foundation.
Q. We’re looking to buy a home in a settled area near national schools in Cork City’s southside. Our choice is more confined to older houses. Lots that we have looked at have acknowledged issues with subsidence and leaking drains, some of it has been addressed, more not touched, often where the house owner had been elderly. We’d be prepared to buy if the purchase price is right (and the cracks not too worrying!), and tackle it later on when we extend, but may not get a mortgage for this. We’re not cash buyers. How big a deal is it in Cork, and why are remediation costs so high?
A. Subsidence is certainly a significant issue in the older housing stock and didn’t really taper off until the 1980s, causing many a homeowner sleepless nights and worryingly large bills, stress, and inconvenience.
So what causes subsidence, what can be done to alleviate it, and how does this apply to your future plans in terms of cost and timing?
Subsidence is caused by a deterioration in the bearing capacity (strength) of the ground under the foundations of a house. It may be that a house was built on weak or rebuilt ground or, more commonly, it may be that the drains or a water main may be leaking into the ground locally thus changing its composition and causing a local weakness in strength.
In new homes, subsidence is rare because uPVC drains are used. These are long pipes that have rubber gaskets (seals) at the ends. They offer a little flexibility and so are quite forgiving in terms of slight movement.
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