Over the years I've used Roll Roofing, which is an asphalt shingl with
grit similar to asphalt shingles, but comes in a 3 foot wide roll. This
stuff has a short lifespan. It tends to buckle up in spots and crack
open and eventually becomes worthless and must be replaced avery five
years or so. I swore I'd never use it again, but I have a cabin/shed
that came with my property that has roll roofing on it. It's been
needing replacement for several years, and I have continued to apply
roofing cement to the bad spots to prolong it, mostly just because both
time and money are short.

At one point, I decided to just replace it with more roll roofing, even
though I knew that was a stupid idea. Thats when I found that the cost
of that stuff has gotten really high. The roof only slopes 2 feet in 14
feet so it's not steep enough for tabbed asphalt shingles. I've pretty
much decided to go with steel roofing, which will only cost about $100
more than roll roofing, (materials) but because of the humps and buckled
spots in the old roll roofing, I'll likely have to strip it all off or
the steel sheets wont screw down evenly. (Or add furring strips under
the steel). Currently money is tight and it's too late in the season to
do this job and risk a snow storm, while I have removed the existing
roofing. But it's begun leaking again, and even after applying a gallon
of roofing cement, it still leaks a little.

I'm wondering if there is another material that can be used that is not
real costly and can be applied right over the existing roof?