The table below shows what levels of insulation are cost effective for different climates and locations in the home.
Attic insulation problems in cold climates.
The higher the r value the better the thermal performance of the insulation.
The first problem was that one inch of closed cell spray foam insulation wasn t enough to keep the temperature on the surface of the foam above the dew point due to the temperature or conditions the house was experiencing.
To repeat the laws of physics tell us that condensation can not occur if the water vapor is prevented from coming in contact with a surface that is cold enough for the water to condense.
Installing a perforated radiant barrier directly on top of attic insulation increases winter and summer efficiencies in mixed and cold climates.
So what was the problem.
Though the loose fill version does lose some effectiveness at very cold temperatures this not a problem for much of california.
What is less well understood is that venting causes many problems in cold dry climates as well.
Not venting the attic avoids this problem.
Avoiding flash and batt condensation problems.
Step 2 measuring.
As home energy readers know venting attics in hot humid climates brings a great deal of moisture into the structure see conditioned attics save energy in hot climates he may june 97 p.
In the summer it reduces heat gain by reducing attic insulation top surface temperature.
However in cases where a vapor drive is consistently moving in one direction such as cold storage applications or swimming pools it is prudent to conduct hygrothermal modeling or calculations to determine if the proposed design is right for the application.
In typical construction and climates building code tables can be followed when using spf as an insulation and air seal.
Standard fiberglass batts and blankets are the best attic insulation because they effectively slow the spread of heat and cold.
Also in very cold climates it is better to allow soffit to ridge venting between the insulation and roof deck in order to reduce the chance of ice dams.
Insulation level are specified by r value.
It will put less stress on your attic floor does not require any additional fire retardant material it will not rot or decay it s eco friendly and will not support mold insects or.
Throughout the balance of this digest the terms attic and roof will and can be used interchangeably.
Find the fiberglass roll insulation with the best r value for your particular climate and attic.
Loose fill fiberglass is also a great solution because it s lightweight.
If your roof beams are less than 16 inches wide you ll need to cut your insulation to make it fit because the rolls are usually 16 inches wide.
The higher the r value the more effective the insulation will be.
In cold climates the primary purpose of attic or roof ventilation is to maintain a cold roof temperature to control ice dams created by melting snow and to vent moisture that moves from the conditioned space to the attic ventilation acts to bypass the vapour barrier created by most roof.
In this case there were two problems.
Also it will not lose its energy saving capabilities over time.
