Many residential roofs will be okay without roof coatings. They will last about as long as the warranty specifies, and then they will need to be replaced. However, there are times when a roof coating is really helpful in extending a roof's life and preventing premature damage. Here are some of those times.

When you live on the coast.

If you live on an oceanic coast, then there is more salt in your air than usual. This salt can be hard on your roof. It can cause metal components to corrode prematurely. Even shingle roofs have some metal components, such as the flashing and the nails. You can have your roof washed every few months to reduce the buildup of salt. However, the roof will still be exposed to salt. That's where a roof coating comes in handy. This coating can form a barrier between your roof materials and any salt that lands on them, extending the life of your roof. It's important to keep roofs strong and healthy on the coast since winds and storms can blow up suddenly.

When your roof is shaded by a tree.

Trees and roofs don't really mix well. A tree can drop debris on the roof, which leads to algae and moss growth. A tree also casts shade and keeps the roof from drying off properly, which further perpetuates these problems and rot. The best solution, in this case, is often to take down the tree, but many homeowners don't want to do that. A roof coating is a good alternative. It helps keep moisture from coming into contact with the roof material, reducing your risk of rot, algae growth, and moss. 

When you live in a really sunny area.

Some sun is good for roofs as it dries them out after rainfall. But too much sun can cause some roofing materials to get brittle. Shingles, for instance, can start cracking and peeling in really sunny areas. A roof coating can give the roof more protection from those endless rays of sunshine. Some roof coatings are also reflective, meaning that they reflect the sun and heat, keeping your home cooler in the summer.

Roof coatings are not always needed, but they do benefit people in many situations. Talk to a roofer in your area if you think you might need a roof coating. They can give you an idea of your options and how much each coating costs.