How to Refinish a Top-Nailed Antique Oak Floor

An antique oak floor needs special care when you refinish it, whether it's top-nailed or not. The older the floor is, the more likely that it has been oversanded, and if it has, you can destroy it by sanding again. The safest approach is to set the nails and do a screen and recoat.

When Sanding Is Safe

Before you sand an antique oak floor, press a flathead screwdriver into the joints between boards in several places on the floor. If you feel any give, the part of the groove that covers the tongue has been sanded thin, and it will probably break if you sand again. If the wood feels, solid, on the other hand, you can probably sand the floor safely, although you shouldn't sand with paper coarser than 80 grit. Just be sure to set all the nails with a nail set and cover the holes with filler before you sand.

Screen and Recoat

If your test reveals weakening of the boards, you can still improve the finish by doing a screen and recoat. In this process, you use a floor buffer to scuff up the finish -- which you've cleaned with wax-cutting detergent -- and you spread one or two new finish coats. Screening with a 120- or 150-grit sanding screen doesn't touch the wood, and while it won't solve problems like warping or fading, it won't wear through either.