Do It Yourself: Engineered wood floor can be sanded

Q. I have an engineered wood floor with a layer of oak on top of the plywood layers. I have scraps that show the oak is only one-eighth inch thick. The finish on the floor, apparently polyurethane, is peeling and some of the boards are impregnated with dirt. Can this floor be restored and what is the best approach?

A. Most engineered wood floors can be sanded and refinished at least once, sometimes two or three times. Only about 1/32 inch of material usually needs to be removed from the top layer, called the wear layer. The wear layer is a premium wood such as oak or cherry, bonded to a plywood sandwich.

The best bet is to use a low-speed screen sander, which is easier to handle and much less aggressive than the belt sanders used to sand some solid-wood floors. If you want to do the work yourself, you should be able to rent the equipment from a tool-rental agency.

Most engineered wood is pre-finished by the manufacturer, so don’t take it for granted that this is conventional polyurethane. This is one reason it is best to remove the entire finish if it is badly deteriorated. You can then apply either water-based or oil-based polyurethane and get good results.

In most cases, it is best to have an experienced flooring contractor do the sanding and refinishing. You should show the contractor your scrap wood, so he or she knows exactly how much wood can be safely removed from the wear layer.

Among the advantages of engineered wood flooring is its ability to withstand conditions that would ruin most solid-wood floors. For example, engineered wood can be installed directly over concrete, while solid-wood needs an underlayment of plywood or similar material.

Engineered wood also expands and contracts less than solid wood, and is a good candidate for do-it-yourself installations.

Q. I recently saw an advertisement for pest-control insulation and wonder if this stuff would help my pest problems. I have a yearly inspection for termites – would the insulation help control termites? I think I could use more insulation in my attic. What is your opinion?

A. Many pest-control insulations are impregnated with borates such as boric acid. Boric acid is often used to control some household pests, such as roaches, ants, some beetles and, according to some sources, termites.

However, boric acid must be contacted by the pest. It is effective when the pest picks up the pesticide when it walks or crawls through it, then ingests it.

Boric acid is considered a relatively safe pesticide, although long-term exposure could have some adverse health effects.

I have not been able to find any independent tests of boric acid’s effectiveness when used in insulation. The Internet has a great deal of information on pest-control insulation, but most of the links are posted by dealers and manufacturers, so they might not be completely unbiased.

My main concern is that the insulation adds another chemical to the long list of chemicals already found in most homes. But if you are seriously interested in pest-control insulation, my suggestion is to start by reading some of the Internet reports on boric-acid safety when used as a pesticide.

You can find some in-depth information by using a search engine and the words Safety of Boric Acid Pesticide. If you remain interested, seek out a contractor who gives free estimates. Ask questions about the safety and effectiveness of the specific insulation in controlling pests, and get written documentation if possible.