QUESTION: I live in an older mobile home. It is uncomfortably hot in the summer and chilly in the winter. What is the best method for adding insulation to the roof?
ANSWER: Typically, there are only 1 to 2 inches of roof insulation in older mobile homes, and it may have settled and deteriorated over the years. A properly insulated roof can cut your total utility bills significantly, especially air-conditioning costs, and increase your comfort year-round.
An excellent method to increase the insulation level of your roof is to add a roof-over. This is actually a second roof built over the existing one. Additional insulation is first laid over the old roof.
There are two basic types of roof-overs for mobile homes. One type uses a sheet-metal roof made of aluminum or steel. The other type uses a heavy, flexible "rubber-type" sheet. This is the same type of flexible material used to cover some football stadiums.
The flexible roof-over offers several advantages. Since it is a continuous membrane, it waterproofs your roof. Some are manufactured as a single sheet and others are pieced and glued together at the site. The flexible sheet is sealed around the top edge of your mobile home with caulk and fixed in place with an aluminum strip around all the edges.
Since it is nearly white, the new flexible roof also reflects away much of the sun's heat. This significantly reduces the amount of heat that radiates in through your ceiling. Roof rumble and noise from rain and hail are also reduced.
If you are handy with tools, you should be able to install a flexible roof-over yourself. You can purchase them in kit form with do-it-yourself instructions. It is often less expensive to locally purchase some of the items, like insulation.
You have a couple of choices for insulation. One option is a very high-density fiberglass batt insulation. It must be very dense so it doesn't permanently crush under the weight of the sheet material and rain or snow.
Another method uses rigid foam board insulation. This packs in more R-value per inch and produces a very flat and level look to the roof. It is slightly more expensive than the fiberglass batt insulation.
You can write to me for Utility Bills Update No. 380, showing a list of manufacturers of flexible and sheet-metal roof-overs, information and specifications of roof-overs, sample do-it-yourself installation instructions, and a small sample piece of the flexible sheet. Please include $1 and a self-addressed business-sized envelope. Send your requests to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.
Oversized Fuses Can Lead to Dangers
Q: My house still has fuses in the electrical panel. There are 20- and 30-amp fuses in it. Would it save any electricity to put 30-amp fuses in all the sockets to reduce the resistance through the fuses?
A: You should never increase the size of the fuses in a panel. The fuses are sized based on the gauge of the wire in the walls. If a small-gauge wire carries too much current, it can get too hot and cause a fire. A larger-capacity fuse will not reduce the overall resistance and losses.
Especially in an older house, fuses often blow. When the houses were built, they were not designed for many large electrical appliances. Although fuses sometimes are a hassle, they offer excellent protection.