Attic Insulation options
I am evaluating the options on upgrading the insulation on my lake house. The house is in Zone 5 (hot and humid) and the main concern in improving the comfort and efficiency in the summer months. The ceiling has blown insulation about R 30. The air conditioner and ducting are in the attic on the west side of the building. To improve the heat in the attic I am looking at insulating at the roof line. The two options are blown foam in the roof or ridged foam board with foil wrap. I have been told that foam is problematic with older asphalt shingles due to increase heat at the roof line. The ridged foam can be attached under the roof rafters to form a solid air tight attic. The space below the roof deck and above he ridged foam would be vented from the soffits to the vents in the roof peak. This would allow some heat relief for the shingles.
I need to determine if the ridged foam is feasible or advisable.
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