Do you have wood planks in your floor that appear raised at the edges more than in the middle? If so, then you are faced with the problem of a cupped floor. Cupped floors are a common problem when it comes to timber floors so you shouldn't fret if you are experiencing the issue for the first time.
What Causes Floor Cupping?
Cupping usually originates from an imbalance of moisture content in the woods; the woods are bound to cup and take on a concave shape if there is increased moisture content in the bottom of the woods compared to the top. This is the same thing that happens when a strip of paper is laid on a drop of water. The paper tends to curl up away from the absorbed drop of water.
But besides water, vapor from the air can also cause cupping of the floor. In fact, air that possesses relative humidity that is above zero contains water vapor that can cause cupping. Relative humidity, which is expressed in percentage, is the amount or volume of moisture in the air compared to what the air is capable of holding at a given temperature. For water vapor, however, cupping manifests itself slowly. That is why it sometimes takes weeks, months and even years to spot wood planks that have raised edges.
How Do You Repair Floor Cupping?
The first and the most important step during cupping repair is to prevent water from accessing the woods. Check if there are leaking appliances in your house such as your dish washer or your washing machine. Also check for leaking pipes or faults in your walls that might be allowing rainwater to percolate inside the house.
Once you have taken care of the water sources, correct the moisture levels by getting rid of excess moisture in the house using a dehumidifier. Then give the boards some time to dry out, and as you wait, take moisture readings bi-monthly or bi-weekly using a sling pyschrometer so that you can accurately determine the humidity levels. If the moisture readings between the back and face of the boards are not balanced for at least one month, do not commit to repairs. You should wait until the readings are balanced. Also note that boards that have a surface finish tend to dry out slower.
When the boards have completely dried out, they should be able to return to their normal shape. Hence, re-secure the loose boards to the subfloor. If the floor was installed using nails, check the floor carefully for loose nails. If you get squeaks from the floor, you definitely have loose nails. Face-nail the loose boards or refasten the boards with wood screws. And if you spot cracks after fastening the boards, cover the cracks using commercial wood putty.