When wood absorbs moisture from the surrounding environment, it expands. If you have a hardwood floor installed above ground, you'll notice that the gaps between the boards are smaller in the summer and wider in the winter. This is your floor responding to the moisture in the air. Basements are even worse when it comes to moisture in the surrounding enviornment. If exposed to an excessive amount of moisture, a hardwood floor will expand considerably. With nowhere to go, the floor will start to buckle as it push against the walls and other boards. This can ruin your floor.

So how do you know if your basement is dry enough to install a hardwood floor?
You could use a moisture meter or you could simply tape a square foot of clear plastic to the concrete slab using duct tape. If after 24 hours, you find condensation under the plastic, then you know that the basement is too moist for a hardwood floor.

 

If your basement passes the above tests and you’d like to replace the carpet in your basement, then you have a couple of options:

1. Choose a material that doesn't absorb moisture - like cork. Cork floors are made of the same materials in a wine stopper and resists moisture considerably.

2. Avoid a solid hardwood floor and install an engineered or longstrip hardwood floor instead. An engineered or lonstrip hardwood floor is made of several layers glued together with alternating directions of the grain. This creates greater stability because it counteracts the natural tendency of hardwoods to expand, contract, warp, or cup.

Engineered hardwood floors can either be glued down to the concrete itself or floated above the concrete. With a glue down installation, the adhesive will act as its own built-in vapor barrier that will keep moisture away from the wood itself.

If you go with a floating engineered or longstrip floor installation, you'll want to use both an underlayment as well as a vapor barrier. The combination of these should keep moisture away from your new hardwood floors. However, keep in mind that if your basement floods frequently, even these safeguards won't help.