I'm in the middle of replacing a small roof above an entry-way. It is an area of about 100 square feet (9.3 square meters). The top layer of shingles were completely worn out and came off easily. The bottom layer is stuck as if with glue to the sheathing. It seems as though instead of tar paper, the original roofer just spread actual tar instead of using tar paper (or the tar paper degraded and fused with everything around it). I was able to pry up the parts of this bottom layer that overlapped other shingles and get most of the nails out, but the stuck parts are better fastened to the sheathing than they are to themselves. In other words, they aren't coming off. I would like advice for how to proceed among these four options:
Just put new shingles on top of what is left of the bottom layer of shingles
lay out tar paper or felt over what is left of the bottom layer of shingles and then shingles.
take the next several weeks to slowly scrape this tarry, shingle-shaped goop off my roof with, I don't know, a blow dryer and a cheese slicer?
I guess pulling up the sheathing itself is an option, though it is beyond my skills, I think
The entire roof had an ice and water shield that was sticking the shingles. This guy's write-up about his roof closely mirrors my situation in that it was south facing, low slope, and old.
After deciding to just lay shingles onto the remaining old shingles, I noticed that the sun warmed up the substance to the point where it was relatively easy to peel off the stuck shingles with the roofer's spade. So I got the old shingles off, put down felt and applied new roof. Thanks!
We just had this problem and was prepared to go over what ever wouldn't come off. Suddenly it became cloudy and the temp dropped about 15 to 20 degrees. What had been a sticky mess like trying to get flys off fly paper suddenly became brittle and wanted to chip off. It was still work but working around from diffrent sides using a shingle shovel with small teeth at about a 45 degree angle we got about 99% off. The ice and water will be on there till the house falls down. The sun is not your friend cold is better.