CHECKLIST

Blowing hot and cold

Because Guam does not experience four seasons throughout the year, insulation serves one primary purpose for a home: keeping the hot air out and the cool air in.

Concrete homes are not as sensitive to temperatures as wooden homes that are typically seen in the continental United States. This means that concrete homes are better at retaining hot and cold air, but that may not always be a good thing. For instance, long periods of sunny weather can heat up a concrete home, making it more expensive for energy appliances to cool the interior.

The first approach to insulation is to have heat “bounce” off the home’s exterior. White or reflective paint on the roof or the side of a home where direct sunlight hits can help reduce the amount of heat absorbed. The Guam Power Authority recommends checking if the roof has a vapor barrier — in the form of tar paper, fiberglass batts, or a plastic sheet — that can prevent moisture from entering the home.

“Moisture can reduce the effectiveness of insulation and promote structural damage. Make sure that the roof vents are not blocked by insulation. Seal any electrical boxes in the ceiling with flexible caulk and then cover them with the recommended insulation,” GPA said.

A good structural foundation can also prevent cold air from leaving the interior. Tevita Tuituu, a certified home inspector with Home Solutions Guam, said a visual inspection every now and then can help in figuring out where air is leaking in or out.

“Homeowners should call a professional once they notice any slight changes to the structure and foundation. Excessive cracks throughout the home are one sign. Cracks on the floors and walls that start out as a hairline cracks and continue to get larger mean it is time to call a professional,” Tuituu said.

It is also important to consider the method by which a concrete house was built, either through concrete blocks or insulated concrete forms. The latter is a more modern approach that uses polystyrene foam — a good insulator — to guide the pouring of concrete to form a wall. Older Guam homes likely used concrete blocks, but this can be verified with a home inspector. p