Hitting the Roof

Hal Muller recently wrote (“Letters,” Nov. 14) that roofing felt is not just a backup waterproof membrane, but the primary moisture barrier. If it is either of these, then I may be in for big trouble.

I recently had my house re-roofed by a reputable local roofer, and discovered that the workers were making long horizontal knife cuts in the heavy tar paper.

When I asked, a worker told me this was standard practice, done to level out roofing paper that had buckled a bit in the hot sun. Otherwise the shingles wouldn’t lay flat and the job would look bad, he said.

Not convinced, I called some other roofing companies and even the local Department of Building and Safety. They all admitted this was a common practice. I was told by one that the real job of roofing felt is to create a flexible interface between the composition shingles and the wooden roof sheeting. Who should I believe?

KENT STRUMPELL

Los Angeles

Editor’s note: Can any of our roofer readers help out here?