Insulation can help around crawl space

Q. Part of my home sits over a crawl space and the floors in that area get extremely cold in winter. Would adding insulation in the crawl space help? Would there be moisture problems if insulation is added?

A. Insulation in the crawl space will help improve the comfort of the rooms above it. You use the word “add” so I suspect there is already some insulation between the floor joists over the crawl space.

More can be added there, but it should not have a vapor barrier attached. (If there is no insulation between the joists, a vapor barrier can be used in cold-climate regions and should be on top, facing the heated part of the house.)

In most cold-climate regions of the nation, insulation rated at least R-25 is recommended, the equivalent of about eight inches of fiberglass. If winters are very cold, even more insulation is recommended.

You can check the recommended level for your area by visiting www1.eere.energy.gov/ consumer/tips/ insulation.html. A zone map gives the recommended levels for new construction. You will note that some floor insulation is recommended even in regions with very warm climates.

Unfortunately, it isn’t always possible to achieve recommended insulation levels in existing construction. For example, the floor joists over your crawl space might not be deep enough to hold eight inches or more of insulation. If not, add as much as you can.

The insulation blankets or batts are often supported by stiff wires jammed between the joists under the insulation.

You can also help avoid moisture problems in a crawl space by covering the floor with a layer of thick plastic sheeting. Overlap joints and hold the plastic in place with bricks or lengths of 2-by-4.

Crawl spaces that have water pipes, heating ducts or similar equipment in them are best insulated by installing the insulation on the inside walls of the space rather than in the ceiling. If in doubt, consult building-code officials in your area.

Q. We suspect there is mold in some parts of our house. Can we use a do-it-yourself mold test kit to track it down?

A. Mold test kits, unlike test kits for some other problems such as lead paint, are not considered reliable for home use. The best way to find if there is mold in your home is by visual inspection.

Mold generally requires moisture to grow, so check places that are wet or have been wet. Likely spots are around plumbing fixtures that might be leaking, under carpets, and even inside walls.

You can recognize mold by its color, which might range from white to black. It usually has a powdery or dirty appearance, and often has a musty odor.

Small areas of indoor mold can generally be cleaned up with a solution of chlorine bleach (one cup to a gallon of water) or with a detergent solution. Severe mold infestations usually require help from an expert.

Q. Can WD-40 be used to degrease my kitchen wall tiles and stove top? Is it flammable?

A. WD-40, the spray lubricant and all-around solvent, has many uses, and degreasing is one of them.

However, it is normally used to degrease tools and machinery rather than kitchen surfaces. It is also flammable, and you will find a warning to that effect on the container.

Frankly, I don’t think it is a good choice for the uses you have in mind. You can buy good, nonflammable degreasers at most supermarkets and home centers.

You can learn more about WD-40 at www.wd40.com.