Do it yourself sanding or buff and coat?

Q: My fiance and I recently purchased a home with maple flooring (thick tongue and groove). The home is roughly 40 years old; not sure of the floor. It appears to have been previously refinished with a polyurethane.

My questions to you are: what should be used to fill the long gaps between boards(1/16″ to 1/8″) at most? And second, should we take the floor completely down by sanding, i.e. start over with the finish, or buff the floor with screen and buffing pads before re-coating?

We are looking to accomplish this task ourselves and would encourage any input you may have.

A: There are any number of wood fillers on the market for professional use, coming in tubs and tubes as the need might be. If you only have a few gaps to fill, you may want to take a look at Colr-Rite tub fillers that come in hundreds of colours. It can be a bit of a problem matching maple because the colour can be quite a bit different between boards, so the filler may be to dark or to light. You may have to get more than one shade. Or buy a small tub of Woodwise, Bona Kemi or Final Touch either online or from a local hardwood retailer. It comes in different species. If you don’t intend to sand the floor completely, fill the gap and wipe the excess residue from the boards surface with a damp cloth.

To completely sand or just buff and coat will depend on the condition of the existing finish. If there are areas where it has totally worn off, leaving the wood grey and discoloured, the only choice really is to do a complete sanding to expose fresh wood and start over. I must warn you, this work is really best left to the professional. It is technically and physically difficult work.

If a buff and coat are all that is required, to freshen up the top coat, you will have to make sure there are no contaminants on the floor surface that will impede adhesion. You will need to thoroughly abrade or rub down the existing finish with fine sand paper or suitable abrasive and may be wise to try a couple of sample areas off in a corner to see if you can get good adhesion. There are cleaners designed for use with polyurethane coatings that can help to remove contaminants. Talk to your local flooring supply store.