Avoiding flash and batt condensation problems.
Attic insulation problems in cold climates.
What is less well understood is that venting causes many problems in cold dry climates as well.
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.
Installing a perforated radiant barrier directly on top of attic insulation increases winter and summer efficiencies in mixed and cold climates.
Standard fiberglass batts and blankets are the best attic insulation because they effectively slow the spread of heat and cold.
For cold climates loose fill fiberglass insulation is the best as it has an r value of 60.
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 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.
Not venting the attic avoids this problem.
Insulation level are specified by r value.
In this case there were two problems.
The higher the r value the better the thermal performance of the insulation.
Also it will not lose its energy saving capabilities over time.
So what was the problem.
Find the fiberglass roll insulation with the best r value for your particular climate and attic.
In the winter it reduces heat loss from convective looping and wind washing.
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.
R value is a measure of insulation s ability to resist heat traveling through it.
Step 2 measuring.
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.
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.
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.
Throughout the balance of this digest the terms attic and roof will and can be used interchangeably.
The table below shows what levels of insulation are cost effective for different climates and locations in the home.
In typical construction and climates building code tables can be followed when using spf as an insulation and air seal.
The higher the r value the more effective the insulation will be.
