Cracks on Concrete Slab

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Q: I am buying a new home. There are several cracks on the concrete slab, and each crack is about six feet long. One of the cracks starts from the wall. I don't know whether or not those cracks will cause some problems later to my house.

I don't know what are the normal or the unacceptable cracks? What problems will those cracks cause to my house? Do I have the right to ask the builder to fix those cracks? If they don't fix them, do I have the right to cancel the contract to buy that house?

Do you know any inspectors that I can hire to inspect those cracks only? In two weeks they will start putting the cabinets in, and the house may be finished soon. I don't know what I should do now. Please give me your advice!

I asked the builder and they said the cracks are normal, and they don't fix them. Some of my friends tell me that they have had some cracks in their concrete slabs, and those cracks damage the tile floor and allow water to moisten the carpet.

A: It is true that concrete frequently cracks no matter how well the contractor has done his job. Some cracks are no problem, as your builder claims, but other cracks can be a problem and allow moisture to come up through the slab and damage the flooring and perhaps some furnishings.

I had that problem in my own new home 11 years ago, and we could see cracks under our vinyl floor. Our builder had to remove the vinyl, fill the cracks, seal the concrete and install new vinyl flooring. When we happened to replace some carpeting a few years later, we discovered similar cracks in the slab under the carpet. However, perhaps because we had installed excellent drainage around our yard to divert water away from our home, we have never experienced moisture or any other problems as a result of cracks in those areas of the slab at all. So it really does depend.

For your own peace of mind, I recommend you contact a reputable home inspector and pay for a report about the severity of the cracks. If he says the cracks are acceptable, then you can relax (but take some pictures and keep the report just in case they get worse because a builder must warranty a house for latent defects for 10 years).

However, if the inspector recommends they should be fixed, show the report to your builder. If he refuses to do anything, tell him you will be filing a complaint with the State License Board, with the report.

I would expect that most reputable builders would want to save the sale, eliminate any hassles with the SLB and determine it would be quicker, easier and cheaper to fix the cracks at this stage of construction. However, if he doesn't, you will have to decide if you want to wait for the SLB to get involved and determine if the cracks should be fixed, get out of the sale now, perhaps contact legal counsel, etc. I hope it doesn't come to that!

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by Kathy Maynard, reprinted courtesy of

Cracked Concrete

Install Your Own Concrete Flooring