The roof must be thoroughly cleaned, and allowed to dry thoroughly. This is a critical step to ensure a successful coating application. Be careful not to damage the lap seams. Care should be taken when pressure washing not to disturb the integrity of the underlying roof membrane particularly where there are adhered seams. Refer to the specific coating manufacturer you are using for their specific requirements for roof preparation.
One of the best ways to achieve it is to use the Heng’s rubber coating that can protect it from the elements, including sleet, wind, rain, and snow and UV rays. The product also does well in keeping our roof protected from dirt, leaves and twigs. With such protection received, our roof won’t degrade and we prevent ruining our recreational vehicle investment.
We had issues with getting this foam to turn green in summertime in the South. We needed up spending an additional $300 on being able to spray this foam: 110 window a/c for shop & a $60 tarp to drape over the top, to keep the temps down. The areas where we had trouble-shooted were sticky & even after we wiped it down, the new green foam wouldn't stick. My husband had to apply Liquid Nails to it. For over $800, I expected alot more, plus the sellers customer service skills were in need of improvement. http://www.youtube.com/v/ggLAUsiuI_o&feature=kp
One of the key differentiators between traditional insulation materials and spray foam insulation is the latter’s ability to insulate and air seal. Foam insulation provides an air barrier to wherever it is applied to help mitigate air leakage from the building. Air sealing the building envelope with sprayed-in foam insulation also helps address moisture ingress to reduce the risk of mold and mildew growth as well as the formation of ice dams in colder climate zones during the winter months. When you compare foam insulation with traditional fiberglass insulation and cellulose insulation, sprayed insulation minimizes air infiltration, it assists in limiting moisture vapor from entering and escaping the home, which in turn reduces the load on heating and cooling systems. Below is a video that compares fiberglass, cellulose and open-cell spray foam in terms of insulating and air sealing value.
Roof Spray Foam Insulation