Flooring glued to concrete buckling

Q: We have recently had a solid oak floor laid in our living/dining area. The floor consists of oak planks (160mm x 20mm) glued directly onto concrete subfloor. Unfortunately the floor has buckled severely in couple of areas.

How do we rectify this matter without incurring huge costs? Will it go back naturally with the aid of a dehumidifier or would we have to replace the whole floor?

A: I am not sure why you elected to have solid 3/4 thick oak “glued” down, rather than having a sub floor constructed which could be nailed to, or else using an engineered product such as Mirage engineered that is designed for this sort of installation. Whatever the reasoning may be, the one element that will cause such buckling is moisture migrating into the hardwood floor. Either you have a leak or moisture is coming through the concrete. Did the installer check to see if the concrete was and remained dry, or was bleeding moisture?

You will have to correct the moisture issue first. You will also have to remove the damaged areas, remove the adhesive from the concrete as much as possible and proceed to install only when the concrete is dry and the moisture issue is solved.

Bostik’s Best or equivalent urethane adhesive is best for a project such as this. There are also products that can be applied to serve as a vapour lock. Using the proper size notches on the glue spreader is also important.

A dehumidifier won’t help you in this case because the adhesive is already cured.

Related Q: Approximately 4 months ago, we had engineered flooring installed in our home. Lately, we have noticed that in certain areas the flooring is releasing from the concrete sub floor. Would you know as to why our flooring is acting this way and if there is anything we can do to fix this problem?

A: Pretty tough to comment on that. I don’t know the adhesive used. I don’t’ know if moisture tests were done (though it doesn’t sound like it is a moisture problem). It could be something as simple as the wrong notches in the trowel to spread the adhesive. Did they roll the floor after installing?