Energy Conservation-Shallow Energy Retrofit

This post originally appeared on the Green Building Advisor website.

Several years ago, I performed a roof replacement for a customer, the customer wanted to change their older and failing asphalt shingled roof to a steel roof.  We stripped the old shingles and existing underlayment off, installed new synthetic underlayment and new steel over the 10/12 pitched roof.  I felt confident that this new roof would last many years.

The following year, the same customer asked if we would replace several windows in the upper level of his story and a half home.  The old windows were due for replacement, the single paned wood units appeared to be from the mid-1900’s.  Woodpeckers had pecked a hole nearly completely through one of the windows.  Several others were painted shut.  Again, a straight-forward job we had done dozens of times before.

The home with the roofing and window replacement that resulted in “attic rain”.

The spring after the window replacement, I received a call from the customer saying his roof was leaking.  He had water dripping in several areas in the upper level of the home.  A visit to his house did indeed show water damage, though it was not the result of a bulk water leak from the roof, but instead, air leaks from the interior had formed frost on the attic side of the roof sheathing, the home had never had this issue before.  I surmised that replacing the five upper-level windows had changed how this home handled air and moisture just enough to cause frost to form in the attic.  My first building science lesson about the unintentional effects of a shallow energy retrofit. Continue reading “Energy Conservation-Shallow Energy Retrofit”