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We bought a new house about a year ago. It came with a one year guarantee from the builder. Immediately after we moved in, we noticed that anything we set on the garage floor became wet underneath, and left a dark, wet spot where the object had been. The floor looks dry otherwise. The garage floor also produces a chalky, white powder (I believe this is called “efflourescence”) that I sweep off about once a month. Clearly, we have water wicking up through the concrete. None of our neighbors has this problem, and all the houses were built by the same company. The builder has been reasonably attentive to our wet floor, and did dig a trench to the depth of the stub wall around two sides of the garage and installed a drain. This has had no effect at all, even five months later.
Suspecting insufficient gravel under the floor, I asked the builder to drill two, 4-inch core holes in the concrete in the wettest spots so we could inspect the gravel underneath. I found plenty of gravel underneath – it was a tad silty and a little damp, but certainly not soaked with water. There has been no change in these holes since they were drilled a month ago.
The builder is unwilling to spend any more money on our garage floor, mainly because it is hard to pinpoint the source of the water. They believe the garage was built to code, and have thus fulfilled their obligations. Their opinion is that the soil under the garage (heavy western Oregon clay) was wet when the house was built, and that over time all of that water will evaporate through the concrete. Our position is that the garage floor is defective – we should be able to set objects on the floor without them getting wet on the bottom. In addition, the efflourscence suggests the concrete is deteriorating.
I am at loss as to how to proceed. Why would our house have this problem when our neighbors’ houses do not? What is the builder’s obligation in this situation? Should I hire an engineering firm for an evaluation? Should I hire a lawyer??
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In addition, the efflourscence suggests the concrete is deteriorating.
Why?
*Actually, the idea of the efflourescence being an indicator of deteriorating concrete is a presumption on my part. Am I wrong?
*i we should be able to set objects on the floor without them getting wet on the bottomMaybe on an older concrete floor.
*Dan, it is either built on silty gravel or clay. If it is built on clay you need to understand that the small particle size of the material makes the clay very reluctant to release moisture, and will do nothing to help dry out your slab.You might try to run a de-humidifier and see if that helps by keeping track of the humidity level. If the building is properly drained, both above and below ground, you may find that this will solve your problem.
*DanThe water wicking through the slab contains dissolved mineral salts. These are deposited in the form of a white powder on the surface of the concrete when the water dries out.
*Providing the top of the garage slab is not below ground level, a simple cure would be to coat the slab with epoxy paint -- like swimming-pool paint.The fact that the slab is wet won't harm it.
*Guys - This is why you want an 8-mil to 10-mil vapor barrier under every slab, period. Dan - did you note any plastic?Jeff
*No, there was no vapor barrier under the concrete. Allegedly the code says that since the garage is not an inhabited space, a vapor barrier under the slab is not required.
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We bought a new house about a year ago. It came with a one year guarantee from the builder. Immediately after we moved in, we noticed that anything we set on the garage floor became wet underneath, and left a dark, wet spot where the object had been. The floor looks dry otherwise. The garage floor also produces a chalky, white powder (I believe this is called "efflourescence") that I sweep off about once a month. Clearly, we have water wicking up through the concrete. None of our neighbors has this problem, and all the houses were built by the same company. The builder has been reasonably attentive to our wet floor, and did dig a trench to the depth of the stub wall around two sides of the garage and installed a drain. This has had no effect at all, even five months later.
Suspecting insufficient gravel under the floor, I asked the builder to drill two, 4-inch core holes in the concrete in the wettest spots so we could inspect the gravel underneath. I found plenty of gravel underneath - it was a tad silty and a little damp, but certainly not soaked with water. There has been no change in these holes since they were drilled a month ago.
The builder is unwilling to spend any more money on our garage floor, mainly because it is hard to pinpoint the source of the water. They believe the garage was built to code, and have thus fulfilled their obligations. Their opinion is that the soil under the garage (heavy western Oregon clay) was wet when the house was built, and that over time all of that water will evaporate through the concrete. Our position is that the garage floor is defective - we should be able to set objects on the floor without them getting wet on the bottom. In addition, the efflourscence suggests the concrete is deteriorating.
I am at loss as to how to proceed. Why would our house have this problem when our neighbors' houses do not? What is the builder's obligation in this situation? Should I hire an engineering firm for an evaluation? Should I hire a lawyer??