We want to re-shingle our roof. However, we have been getting conflicting advice about the use of tarpaper underneath the shingles. Some contractors say that it's not necessary. Some say that two rows from the eaves trough is enough. One contractor told us the entire roof must be tarpapered. What is your opinion about the use of tarpaper?
Answer:
Along the bottom you apply ice and water shield high enough so that it is at least 9" past the exterior wall. Then you apply tarpaper all the way to the top. My experience has been that when I take shingles off a roof that has no tarpaper, I find all kinds of rotted decking. Where there is tarpaper, there is no rot.
