The purpose of insulation, is to act as a barrier against heat gain and heat loss. It is particularly necessary in walls, floors, ceilings and roofs and is by far the most effective and cost-efficient method of ensuring a home’s energy efficiency. Preventing heat and cold loss helps keep your home cooler in the summer and warmer in the winter. This directly affects your utility bills. Well insulated homes also provide a barrier against road noise and air pollution.
Keeping your walls well insulated can make a drastic difference in your utility bills. The ability to do that depends on whether you have solid or cavity walls. Older homes tend to have solid walls, meaning insulation cannot be blown between the studs.
Cavity walls are much easier to insulate since insulation can be injected into the cavity, which will reduce heat and cooling loss. If you feel that your rooms don’t retain heat or cool air very well, then adding more insulation might be a good solution.
According to the Department of Energy, there are several places in your home that need good insulation:
Normally, most types of insulation have a very long lifespan, but there is a wide range of quality and efficiency when it comes to choosing proper insulation for your home. Look for insulation that has a high R-Value (the ability to resist heat flow).
Loose-fill is a less-expensive option, but doesn’t resist heat flow as well as higher grades. This can affect its ability to protect your home against moisture damage. R-Value for loose-fill ranges from 2.2 to 3.8 per inch. Fiberglass is lightweight, but is the lowest-rated loose-fill because of its lack of density,
Cellulose has a higher rating and performs well in cold weather, but is extremely heavy for unsupported attics. Loose-fill must be blown using a special machine, and can easily fill in extra negative spaces, however it can settle over time.
Batts & Blankets is the most prevalent insulation used in homes. It comes in large rolls of varying thicknesses and widths. R-Value ranges from 3.0 to 4.5 depending on which material you choose. Fiberglass is resistant to both fire and settling, but can leave gaps, allowing air and condensation to enter. It is fairly inexpensive and can be layered onto existing insulation.
Cotton (“Blue Jeans”) and Rockwool are higher rated options, but can be expensive compared to alternatives. Made of mostly recycled content, they are easy to install but can allow for mold growth if wet.
Insulated panels are the priciest of the insulation options, however, they have excellent energy savings for your home. If you are tearing down walls in an existing home, they can be used, because of their installation process. They are also excellent for insulating siding, or a new home addition.
Spray foam has excellent R-Values (3.5 to 6.5) because of the barrier it creates in walls and ceilings. It also fills most gaps and negative spaces.