Using Pacific Filler To Seal Cracks In Maple Floors


We have oak and maple flooring. We have had a lot of moisture in our house and our floors are finally air dried, but we have huge cracks where they all meet. What can I do to seal all these cracks so moisture and air stops coming through. Marge


Dear Marge

There is almost nothing you can do permanently to solve this problem. Why was there a lot of moisture in the house? And what do you mean air dried, and how big are the gaps? What do you mean air coming through, I hope you have a subfloor? The filling methods I’m going to describe will work only if the wood is not loosened from the nails.

You see, if I tell you that you should fill the floor with some sort of trowelable filler, then resand the floor and refinish it, all the filler in time, will crack out anyway. The best and cheapest fillers are made from lacquer finish, or polyurethane and the fine edger machine dust from maple and red oak floors. They will need to be troweled into the floor and in the case of lacquer, need overnight to dry. But the poly filler will take several more days to a week, until it is quite hard.

Then, sand and finish the floor with at least 3-4 coats of oil modified polyurethane finish, and hope for the best. You will need to keep the humidity levels at 40-60% (or less depending on your climate) and from now on, avoid large (30% or more) humidity swings. The lacquer filler sticks well to the wood. But some, not all, of the polyurethane mix has been in my oak floor for 21 years now. The poly mix is very dark, may not look good on a light floor.

If you want to avoid the long dry times and fumes of these before mentioned fillers, you can try the water-based filler called Pacific Filler at More expensive, but better choice of colors, than mixing your own. Most of the cheap brands sold at flooring stores haven’t enough binder to stick to the wood, so stay away from those.