Thanks for all the discussion. This is indeed a small shed, 20X14. The
roof is just a simple slanted deck with no valleys or anything else.
I don't know the term for it, But if you took a flat piece of plywood
and then just tilted it up at the long end a bit, that's what we
have....a sloping piece of roof.
The original roof was shingles, but my husband at the time took them
off when they started to leak and replaced it all with felt and roll
roofing. I remember helping at the time and it was a pretty simple job.
However, it started to leak last spring. A few different roofers all
said it had been face-nailed and they were surprised it lasted the 10
years without a problem.
They all said it should be shingled and while one roofer said it should
be all torn off and started over, the other two said it would be easier
to just put shingles on top of the roll roof, which is in good shape,
except, I guess where the nails are allowing water to penetrate.