If you have a commercial building with a very large roof surface, you may want to consider a reflective coating or paint of some sort. This can deflect the heat of the sun and add some insulation to your building and may also cover over minor cracks and leaks on the roof. Note some commonly asked questions about this type of coating or paint for a roof, and then discuss this option with a roofer to see if it would be a good choice for your building.
What surfaces can be coated?
Just about any roof material can be coated, even a slick metal roof. Bitumen and tar roofs also hold a coating very well. The only exception might be roofs with a gravel surface or any type of specially treated roof. A roofer can note if your building's roofing materials are a good candidate for a coating if you have concerns about its surface.
Will coating fix all holes and leaks?
As said, the coating may seep into small cracks and leaks in the roof and cover them over, but note that a paint or other surface material is not the same as a patching compound. If you're concerned about visible leaks, tears in the roofing materials or outright holes, ask a roofer to inspect those areas and note if they need repair before a coating can be applied.
Is a primer needed?
A primer isn't a substitute for a good cleaning, but it may be needed if the surface of your roof is in generally poor condition. It may also be needed for certain types of coatings and to ensure that a roof paint will not peel or chip and will hold its colour over time.
How long does the coating last?
A roof coating or colouring will usually last several years, depending on the type of coating you use, the condition of the roof and the weather to which it's exposed. When coatings wear away, they can usually be reapplied right over the old layer. This will also depend on the type of coating or paint you choose, the condition of the roof under it and the reason for it to have worn away; for example, if puddling water caused erosion on the coating, the damaged coating may need to be removed before a new layer is applied. An experienced roofer can tell you what to expect by way of any coating's lifespan and what could cause premature damage and erosion.