Hardwood Floor Buckling

klappjack

My house is over 40 years old. We live in Upstate NY and have a full, unfinished basement. About 10 years ago, we remodeled our kitchen, and a couple of years later, our hardwood floor in our family room (off the kitchen) began to buckle in the summer. It returns to normal in the winter.

On inspection from below, I have determined that the sub floor is lifting up along with the hardwood floor above it. I have looked all over for a leak and have found none. Two years ago, we placed a dehumidifier in the basement below the affected area, but this had no effect.

Right after the kitchen remodel, we put our old refrigerator in the basement directly under where the floor is now buckling. After the floor started buckling, we moved the fridge to a new location, but the buckling continued.

I realize I will have to replace the floor and sub floor, but does anybody know what caused this to begin with. I do not want to have the new floor buckle again.

Thank you

Daniel Holzman

Diagnosis for floor buckling requires some photographs. Also requires a description of the exact method of floor installation, i.e. nails, staples, glue. Also what type of hardwood, was it traditional 3/4 inch thick boards, engineered lumber, or glue down squares. What type of subfloor, plywood, particle board, OSB, pine planks?

Floor buckling is usually moisture related, since wood expands perpendicular to the grain as relative humidity increases. Since relative humidity is higher in the summer, at least where you live, wood expands in the summer, and shrinks in the winter. The subfloor may expand at a different rate, depends on the type of subfloor, and method of installation.

The usual method to minimize buckling is to provide an expansion gap around the perimeter of the room. The American Hardwood Flooring Association has specific recommendations for the required gap, which varies by species. If you have too small a gap, the hardwood is likely to buckle in the center of the floor in the summer as moisture in the house increases.

I have an oak floor in MA, which buckles at the center of the house usually starting in late June, then goes back to normal in the winter. Probably too small a gap around the outside of the house. A dehumidifier would help, but I don't care to pay the electric bill for such a device, so I live with it.

klappjack

Daniel,

Thanks for your reply.

My floor is oak on a plywood sub floor. It is the tradition 3/4 inch oak flooring. I don't know if the sub floor is 1/2 or 3/4 inch. I hope it is 3/4. The floor is nailed down. My son, who is a carpenter, thinks the sub floor is being pulled up by the nails in the oak floor.

My real question is why this did not happen until the floor was down for 30 years.

You are right about the dehumidifier bills. The appliance has not helped the situation one iota.

Jack K