If metal roof then similar to above, then at least higher end cost or above depending on roofing materials - (about $1200-2000) unless roofing panels are also damaged, not just ridge vent / cap.
1 Work the soap into a lather all over your hands, scrubbing the skin under and around your nails as well. 2  If you still smell gasoline on your hands after washing them with soap, mix a few drops of vanilla extract with water and rub it into your hands to reduce or eliminate the smell.
I would just put the concentrate straight on the floor and spray it with a little water. Scrub it around with a push broom and then hose it out the door. We used this stuff in the meat department to clean the floors. If it can get rid of the smell of a scrap barrel it can get rid of the smell of gas.