February 1995 Edition

New Shingles Over Old?

Enjoyed reading the article about how to tell when your roof shingles need replacing. I am planning to re-roof my house next summer. Can I install new roof shingles over the  old ones?
The rule of thumb in the Atlanta area is no more than two layers of fiberglass or asphalt shingles on any roof. The problem is that the weight of more than two layers may be too great for the roof framing to handle. The shingle manufacturers typically recommend that their roofing shingles not be used over more than two layers of old roofing.
One problem with installing over the old roof shingles is whether the new roof will lay flat. If the old shingles have curled, then the new roof will not be smooth and will probably have problems with sealing on the row below. One way to eliminate this problem is to break off the curled ends of the old shingles.
With two layers of shingles, the under layer acts as insulation and keeps the outer layer from transferring heat to the roof deck. This could result in some premature deterioration and the life expectancy will probably be less than with only one layer. Excessive heat build up in the attic is another important cause of premature deterioration because of the same heat transfer. Be sure you have adequate attic ventilation.
Because of the expense involved in removing the old roof, many homeowners do elect to put the new layer over the old one.

Furnace Filters Pros And Cons?

My son has allergies and I need to reduce the level of dust and pollens in our house. What type of filter should I install in my furnace and air conditioner?
There are basically five different types of filters used in most of the forced air furnaces today.
The first type is the cardboard disposable filters which are only 3% to 5% efficient. This means 95% to 97% of the dust and pollen goes right through it. They are better than nothing, but not by much.
The second type is the self charging electrostatic filter. Their efficiency is between 15% to 20%.  These filters are charged at the factory and some have been know to reduce the efficiency of the furnace. The cost is approximately $50.00.
The third type is the extended media filter. Their efficiency is between 25% to 35%.  The cost is approximately $300.00 installed and the filter should be replaced yearly. The cost of the filter element is around $80.00.
The fourth type is the high-efficiency particulate arresting filter. They start out at about 40% efficiency but as they retain dirt and pollen, their efficiency can increase to over 99% which is the best on the market. The cost is approximately $400.00 installed and if you do not run the fan continuously it will last around two years before the canister will need replacing. The replacement cost of the filter canister is only about $30.00.
The fifth is the electronic precipitator. These provide efficiencies of up to 96% which is good enough to trap many viruses according to the American Society of Heating and Refrigeration Engineers. The cost is approximately $700.00 installed and the only drawback is that most units should be cleaned monthly. Just remove the filter and drop it in the dishwasher.

Window Condensation?

What causes the condensation on the inside of windows during the winter?
As we make our houses more airtight to conserve heat, moisture is often trapped indoors and sometimes condenses on the windows. Here are a few ways to control condensation:
Try running your furnace fan continuously, which keeps warn air circulating in the rooms and keeps the inner surface of the windows a bit warmer.
If you have a crawl space, be sure there is a good vapor barrier on the ground, and if your basement is damp, keep the door closed.
Use a dehumidifier in the basement if there is a moisture problem.
 Always use the exhaust fan in the bathroom when you shower. If your bath does not have one, install one that is vented through the roof.
Use the kitchen exhaust fan when cooking.
If  you have a humidifier connected to your furnace, be sure it is turned down or is off.
Install storm windows or insulated glass windows.
If  you still have condensation, consult a heating and ventilation contractor. For instance, you could install a recovery ventilator to bring in fresh, dry air without losing heat.
This is the best solution to eliminate condensation without heat loss.

Asbestos Flooring?

I plan to remove the vinyl sheet flooring in my kitchen. A friend told me that the flooring could contain asbestos.  What precautions should I take?     
Generally, sheet flooring does not contain asbestos. There can be asbestos present, however, in the backing and adhesive that's left behind after the flooring is removed.
If you are going to remove the flooring, you should first have it tested by a local certified testing laboratory. If asbestos is found, removing the residue is hazardous and not recom- mended, because any method you use is likely to release small particles of asbestos into the air.
The best and safest approach is to leave the flooring in place and put down 1/4" luan underlayment over the vinyl. Then install the new flooring.

Painting Vinyl Gutters?

I am planning on painting my house next summer and want to change the color scheme. Is it possible to paint vinyl gutters?
Here's how Genova, a leading manufacturer of vinyl gutters, recommends painting their gutters:
First wipe down the surface with denatured alcohol (be careful - the fumes are toxic). Next, apply a light coat of Raingo spray paint as a primer base, or any other vinyl siding paint primer. Then paint the gutters with an exterior latex
paint or vinyl siding paint. Genova does not recommend the use of oil-base paint on their product, nor do they recommend painting the interior of the gutter.
However, keep in mind that by painting them you loose the biggest advantage of vinyl gutters - no maintenance. Think twice before you paint, because once you do, you're committed to painting regularly in the future.

If you have a question, change of address, comment, home tip or would like to send Home Tips to your clients, send your letter to Home Tips, Christian Building Inspectors, Inc., 3697 Habersham Lane, Duluth, Georgia 30096. You can E-Mail your questions to us at rodharrison@christianbuildinginspectors.com. We reserve the right to edit questions for length.

Quote of the Month

“You will find as you look back upon your life that the moments that stand out, the moments when you have really lived, are the moments when you have done things in a spirit of love.”

- Henry Drummond

A Tip Of The Hat To:

Diana Coombs

Century 21/Richard Williams, Inc.

Lilburn, Georgia

**** Thank You****