Bob the secret material you are looking for is called dewitts remove it it is a citrus based cleaner in a pump spray bottle and works great on vinyl and aluminum siding i am a roofing contractor in akron ohio and over the years i have tried wd 40 choke and carb cleaner kerosene acetone tsp mineral spirits paint thinner and any other cleaner or solvent you could name all were unsatisfatory.
Removing asphalt shingle siding.
The hard brittle shingle siding and roofing that was used on many homes before 1980 often contained asbestos and should be tested before being disturbed or removed.
If asbestos is found to be present the following safety precautions should be taken if the siding or roofing is disturbed or removed.
It is not uncommon for roof shingles to turn black over time.
How to remove old asphalt shingles before putting on a new roof.
Removing asphalt shingles is a big job and you might be temped simply to lay the new roof over the old one.
When that happens it is generally caused by mildew algae mold or dirt stains.
Roof shingles are exposed to a lot of wear and tear as extreme heat sun wind and precipitation come into contact with them.