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Al Parker
New Floor cracks appearing in older house

About a year ago (last Spring) I bought 1994 colonial in Massachusetts. Several cracks (1/8" wide x 6 to 15 feet each) have just appeared in the concrete basement floor. The cracks are originating from one area. There are no cracks in the foundation. I know that cracking is normal, but thought that this usually happens soon after construction, not 17 years later. The basement doesn't and never had any water leakage problems. I'm also sure that large cracks were not there before; the basement is/was not finished and there is no covering/paint on the floor. Although, it's possible there may have been some hair-line cracks that weren't noticed. The cracks appears some time in the last month. We did/do have a dehumidifier running since June. I don't think the previous owner ever used a dehumidifier, but the dehumidifier really doesn't turn on too in the Winter (when the cracks appeared). It has been a cold/icy winter with the basement temperature now at 50 degrees. Also there had been extra weight on the roof recently do to a lot of snow.

Is it just random chance that the cracks just appeared now after 17 years?
Is the dehumidifier or snow on the roof a cause?
Is this a sign of something worse?

Timothy Miller
Re: New Floor cracks appearing in older house

Howdy cracking slab keep an eye on them to see if they get biger and wider. One can apply a self leveling concrete joint caulk to seal the cracks. Any expansion joints or cuts in the slab? any downspouts concentrating water next to the foundation?

Al Parker
Re: New Floor cracks appearing in older house

Thanks for the response. There are no expansion joints.
There are gutter downspouts that could possibly concentrate water next to the foundation especially with ice now blocking normal flow, but overall there hasn't been much water draining this winter (too cold).
Could water be seeping under the slab? No water has made inside the basement. Last Spring in my area we had a couple weeks of bad rain that flooded many homes (including neighbors) that never had a problem in 30 years but my basement was totally dry.
It seems there should be some acute reason why the cracks would appear now after 17 years so maybe water is the answer.

Timothy Miller
Re: New Floor cracks appearing in older house

Howdy when you say flooded your home... With out knowing more. the soils saturated by flooding may of compacted further the soils under the slab and some settling or heaving, less likely , may of occurred. At this point i would ensure the down spouts drain at least 6 to 8' away from foundation and the slope of the yard is 1/4" per foot for say 10' again for proper drainage and just keep an eye to see if the cracks become offset or wider... The caulking is to prevent radon infiltration and keep water out etc...

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