Hi Alan
Depends on the amount of soiling, if heavy soiled use HWE if only slightly soiled use Bonnet Buffing.
Alternatively there is Dry Fusion which is probably the best option of them all if you have it.
But remember do not use,if you can help it,any solvents on bitumin backed tiles for obvious reasons. If you feel you have to then don't apply it direct to tiles use a terry towel with solvent applied and extract out straight after.
