I recently had an engineered hardwood floor professionally installed (glue down to concrete). I asked the installer about repairing a hollow sounding area in the same type of hardwood floor that had been installed a year ago. He had a small box of nails that looked like pins about 3/4" long but very slender. He hammered the pins through the hardwood and into the concrete. It cured the problem and the head of the pin was virtually invisible. I asked him where he got them and he said, "It's my little secret." I can't find them anywhere. What are they?

They are called sprig nails and dont put them in your floor. They are real bad about backing back out of the floor perfect for a bare foot, ouch! The proper way is with a injectable epoxy not a sprig nail.

Sprigs are a hacks way to collect his check, leaving you with a hazardous floor WHEN, not if, those sprigs back out. They will eventually back out.


Adhesive or epoxy injection, is the professional way of taking care of these hollow spot concerns.