|
Edited on Fri Jan-23-09 12:58 PM by DCKit
1) Other types of insulation allow moisture to migrate. In the winter, it is likely that interior humidity would condense on the inside of your siding causing rot, and, in the summer, that it would condense on the plaster and cause mold. Properly installed foam prevents this migration.
2) Foam fills crevices that no other form of insulation can reach.
You'll need a qualified contractor with a track record and, though the price is high compared to the others, it should provide a higher R-value and, even better, stop nearly all the leaks, further decreasing your heating bills.
Cellulose is no slouch for attic insulation, though the attic has got to be well ventilated to prevent condensation. Further, with the addition of boric acid, it is nearly fire and completely vermin-proof. Since it's comprised of little more than shredded newspaper and boric acid, the price should be the least of any "store-bought" insulation, though I don't know how much pressure our recent energy crisis put on the demand and price of any kind of insulation.
There are also insulating and/or reflective panels that fit between the roof rafters which can channel hot air as well as both insulate and reflect heat (in or out, depending on the season). Hot always moves toward cold and always faster as the temperature difference increases. If you can keep the attic warmer in the winter, you'll lose heat from the house more slowly - Cooler in the summer and the AC won't be working as hard (and you won't need to run it nearly as many days).
If you want to start cheap (compared to whole-house foam and blown cellulose), get busy plugging your leaks, weather-stripping the doors and windows and making some insulating shades/curtains. The return-on-investment of plugging acutal holes, gaps and cracks where the wind moves freely will be much faster than even whole-house insulation and way too much heat is lost through uninsulated glass. A thermal shade can easily have an R-value 2-4x better than a double pane window. You just have to remember to close them at night.
Good Luck!
|