Do hairline cracks in the concrete slab under the carpeting mean that I need foundation repair? Good question. Edward Robinson runs an engineering inspection company in Houston and here is his take:
“Hairline cracks in a concrete slab, even those found below carpeting are not necessarily a measure of foundation performance. If there are floor cracks and abnormal cracks and separations in the superstructure of a building, then there is cause for concern that should be further evaluated by a qualified professional. Cracks typical of those often found when carpeting is removed can be found in the concrete floor of most garages.”
Use the link above to visit Mr. Robinson’s website. I think you’ll find it informative. Keep in mind it addresses foundation issues in the Houston, Texas area. Having said that, any of us with houses sitting on expansive clay soils are sailing in very similar waters.