Reflective roofing foil, preserving siding and no-odor paints

BY DENNIS CREECH

Q:Our builder recommends that we construct the roof of our home using plywood covered with reflective foil to save on air-conditioning bills. Is it worth the cost, and will it hurt the shingles? 

A: The reflective foil your builder is referring to is known as a radiant heat barrier. Studies in the Southeast show that it can be effective in reducing air-conditioning costs, typically in the 5 percent to 10 percent range for a new home with standard attic insulation. The radiant heat barrier reduces the amount of heat that flows from the roof to the ceiling, which means the shingles are a few degrees hotter. However, this slight increase in shingle temperature does not significantly decrease longevity.

Q: The horizontal siding on my home is a wood composite and some of it is deteriorating after about eight years. I want to replace the soft spots and wondered if there is anything I can do to keep the problem from recurring. 

A: When rain strikes the siding, water wicks between pieces. If the back of the siding, and, especially, cut ends are not properly sealed, water can easily get inside, causing rapid deterioration. It is best to prime and paint all six sides of siding before it is installed. This often means keeping a can of paint or sealer and small brush handy to coat the ends as the siding is cut to size. For new construction, it is best to install siding over vertical nailing strips that create an air space between the wall and siding. The air space allows the siding to dry and minimizes the deterioration of paint and wood.

Q: We want to paint several rooms in our home and have heard about “healthy paints” that have no odor. Where are they available?

A: Many major paint manufacturers offer a line of low- or no-odor interior latex paints. The chemicals in paint that cause odors are known as volatile organic compounds (VOCs). Some of these chemicals can endanger health, including causing headaches, asthma, lung irritation and shortness of breath. VOCs can also contribute to the formation of smog in urban areas. VOC-free paints are available in a variety of colors and finishes and offer comparable coverage to standard products.

—Dennis Creech is the executive director and Abraham Kruger is a residential energy expert at Southface—Responsible Solutions for Environmental Living, www.southface.org.