A basement floor made of concrete is porous and can allow water to seep in. Even so, many people lay rubber-backed carpeting on cellar floors in an attempt to make them softer and cozier. Unfortunately, too many times all they end up with is damp, musty carpets that harbor mold, mildew, and odors. In fact, when carpets get too wet, they have to pull them up altogether and start over. These are reasons why experts don’t recommend basement carpeting. That is, however, unless you invest in some type of basement floor system underlayment and have it put down first before laying carpet over top of it.
There are several kinds of basement subflooring and matting options available that are designed to keep your carpet up off the concrete where it can stay dry. Constructed to allow air gaps between damp concrete floors below and the carpeting above, it gives water somewhere to go and allows it to run down a channel to the drain where it can be safely carried away from your basement. These barrier materials are made with waterproof backings to repel the water downward and won’t allow any moisture to seep through the carpet above. The underlayments are ergonomically-designed to make for comfort in walking on them.
If you don’t want to go to the expense of putting down underlayment just so that you can have carpeting, you might consider painting the floors with some type of sealant. These paints will fill minute pores and crevices in the concrete and keep them from getting larger over time. Of course, you will still have a hard cement floor, but at least you’ll be providing a moisture barrier. Even with the sealant underneath, it isn’t recommended that carpeting be used in a damp lower level unless other precautions are taken. You might want to try throw rugs, because they can be easily thrown in the washer if they get damp and musty.
Basement carpeting isn’t the best idea unless you take precautionary measures before installing it. Even then, if you don’t keep the air dry by using a dehumidifier, they will absorb dampness, and if you should have a major storm sewer back-up problem which pumps several inches of rainwater into your basement, carpeting may not be salvageable at all.