More insulation does not always result in better insulation

Dear Jim: My utility bills are high and I am adding a room to my house. I want to insulate the room properly and have the contractor add some insulation in the rest of the house. What type of insulation is best? – Gary M.

Dear Gary: Having proper insulation is imperative for reasonable utility bills. It not only reduces the energy loss (gain during summer), but it also can make you more comfortable by keeping the indoor wall surface warmer during winter or cooler during summer. There is nothing more uncomfortable than sitting near a cold, uninsulated outside wall during winter.

When installing insulation, the amount of the insulation is generally more important than the type you select. This is particularly true in the attic, where the amount installed is not limited by the width of the opening as it is inside of a wall. Your local insulation contractor or building inspector can tell you the recommended amounts for your climate.

Although you often hear the amount of insulation quoted in inches, the true measure of insulation is its installed R-value. The insulation value of different insulation materials varies significantly. Some foam insulation materials can provide almost twice as much insulation R-value per inch thickness as do standard batts.

When you talk with insulation contractors, make sure they quote the R-value of the insulation you are getting. Particularly with blown-in, loose-fill insulation, the density can be too low. This means you get a lot of inches of depth, but the resultant insulation R-value is not as high as you expected.

For your attic, blown-in insulation is always a good choice. This can be fiberglass, rock wool or cellulose. When installed properly, the R-values per inch thickness are similar for these three materials. Check for baffles by attic soffit vent inlets so the insulation does not blow over and block them.

For the walls in your new room, consider batt insulation if you are doing the insulating yourself. Batts with the vapor barrier already attached are simple to install. If you are an environmentalist, as am I, use batt insulation made from recycled cotton denim waste. The cotton is treated for fire safety.

Sprayed-on urethane foam insulation offers the highest insulation levels for limited space inside a framed wall. Closed-cell foams are best.

For both the new and existing walls, adding rigid foam board insulation to the exterior is best. Any type of exterior finish can be applied over it. By having the insulation on the exterior, the entire wall structure is within the insulation envelope.

The following companies offer insulation materials: Bonded Logic, 480-812-9114, www.bonded

logic.com; Certainteed, 800-782-8777, www.certainteed.com; Corbond, 888-949-9089, www.

corbond.com; Johns Manville, 800-654-3103, www.jm.com; and Thermafiber, 888-834-2371, www.

thermafiber.com.

Dear Jim: Even though it wastes water, I rinse my dishes first because my dishwasher does not clean as well as it used to. What are the possible causes of this problem and how can I fix the dishwasher? – Angie I.

Dear Angie: There are two likely causes of poor cleaning: clogged spray holes or a cracked spray arm. Over time, small food particles and hard-water deposits build up and block water flow. Inspect the spray holes and, using fine wire, clean them out. If the spray arm is cracked, the water does not forcefully spray on the dishes. First, try filling in the crack with waterproof epoxy glue. If this does not work, you will have to replace the spray arm.

Send inquiries to James Dulley, Bangor Daily News, 6906 Royalgreen Drive, Cincinnati, OH 45244, or visit www.dulley.com.