My floors were coated with oil-based polyurethane three years ago. Should I apply a low-VOC water-based coat over it or is offgassing done?

Asked by Kim Stern
Greenwich, CT

First, is offgassing still occurring three years after the sealant was applied? Second, I have a baby who will be crawling soon. In addition to the offgassing, I am concerned about his exposure to the floors and the oil-based polyurethane sealant used. Should I apply a less toxic water-based coat to cover the old one? Or would I be introducing more unnecessary chemicals? What is safest for my baby?


Bill Bradbury

Answered by Bill Bradbury

Smithfield, UT

Envirocon Home Restoration

March 15, 2010

I see quite a lot of polyurethane on wood, and I nearly always perform the same procedure on it. Outgassing at this point would be minimal, but polyurethane looks like what it is -- plastic -- and it can be scratched and ingested by little ones.

We sand the floor with a fine screen and a trailer-mounted HEPA vacuum extracts the dust. This removes most of the polyurethane from the surface, but not out of the wood. Then we polish the surface with a good hard-paste wax and a floor buffer. This brings back the luster and shine of the wood, and it gives you that nice old-fashioned look that you probably were going for in the first place. Wax does require maintenance. Bioshield has a nice product called Floor Milk that will clean and polish but not build up. They also carry a nice floor wax for the initial application.

Tagged In: home air quality, floor refinishing

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