Adding Insulation and Air Leak Sealing
Insulation and Air Leaks
I wanted to use these photos to show the difference between the two roofs.
2/3 of the upper roof was built in the year 1863 and are full dimension 2×8 rafters they were insulated with R-19 insulation.
The other 1/3 of the upper roof was built in 1992 with 2×10 rafters and is insulated with R-30 insulation.
The entire roof has a ridge vent and lower Hix vents, which is a continuous vent strip integrated on the roofing drip edge. The Hix vents are located above the gutter area – see photo below – this area is covered in ice. The problem with Hix-vents is that the snow and ice block the air flow.
In contrast, the lower roof, built in 2004, has 2×10 rafters and is insulated with R-30 high density insulation and all penetrations were sealed with expanding foam to seal all air leaks. The upper roof has a continuous ridge vent and the lower vents are located in the sofit and are not obstructed by snow or ice.
This issue is discussed in detail in my previous post: How to seal your attic air leaks and save money.
Solution: when the main building is ready for a new roof, rebuild the sofits and install continuous sofit venting.
Photo below – no issues. See earlier post on ice dams.
~ a concord carpenter