A variety of materials like glass, foam, cellulose, aluminum foil etc are used for Attic insulation purposes. But one of the more favored insulation materials is foam. Despite the fact that foam insulation products are costlier than other types of insulating materials, it is widely used.
Higher price may however be deemed justifiable as R-values of the foam insulations range from R-4 to R-8 per inch of thickness. This is roughly three times more than most other insulating materials of similar thickness. It is also seen that if properly installed, foam insulation is a lot more effective than the rest.
When it comes to foam insulation there can be three options - molded expanded Polystyrene (MEPS)/ extruded expanded Polystyrene (XEPS) or Polyurethane or Polyisocyanurate. Any of these should provide you with very effective insulation. Foam insulation can be done as a liquid or using factory made foam boards.
Liquid foam insulation is done either by applying from small spray containers as a liquid or by means of a pressure sprayed product for heavy duty applications. Both types expand and solidify as the chemical mixture cures. Both spray foam and foam boards are equally versatile and can be used to insulate roofs, walls, foundations, entry and overhead garage doors, pipes and tanks, under basement slabs, or over a slab-on-grade floor.
Be it any type of foam insulation, you must take care to protect it from direct sunlight as the sun's ultraviolet rays have the potential to damage them. For roofs, it’s preferable to apply a coating of tar/ acrylic/ silicone/ rubberized paint. Or else, you can also cover the foam with a rubber or plastic membrane or a layer of asphalt and roofing felt.
Foam board insulation is very effective in preventing the oppressive summer heat from penetrating into your home. It also would help you conserve energy and save on your utility bills. Foam board insulation is a rigid foam sheet, usually four by eight feet (1.2 by 2.4 m) in size, used in nearly all aspects of building construction to provide thermal resistance in floors, ceilings and walls.
Polyurethane and Polyisocyanurate foam board are very similar in content. Foam board insulation is usually placed between the exterior finish and the studs of exterior walls. To prevent air infiltration, it is necessary to place rigid insulation boards tightly together and seal the seams with tape or caulk. Polystyrene foam board insulation is done in much the same way as Polyurethane and Polyisocyanurate foam boards, except for the differences in expansion.
Please bear in mind that foam board insulation is susceptible to deterioration through exposure to sun. Though foam insulation offers no food value to insects, still insects can bore holes into it. Therefore it will be necessary for you to take appropriate precautionary measures to protect your insulation from sun and insect damage.
Foam insulation is not easily combustible but if ignited, it burns and emits dense, black, smoke containing pernicious toxic gases. Because of these inherent perils, foams used for construction will require a covering as a fire barrier.
A lot of precaution is necessary to install foam insulation. You may have to use a mask helmet and gloves. It is even advisable to cover your whole body as foam is hyper allergen and it could lead to dermatological problems. It is wiser that you hire an experienced professional to do the job as the health risk is quite high.