Commercial roofing is not a one-size-fits-all sort of service. There are actually five different roofing methods for commercial buildings, and each one has its own unique set of layers. With each type, the number of layers serves a specific purpose, too. Here are some of those methods, the number of layers they each have, and why they have the layers they do.
One Layer: Single-Ply Membranes
This is just rubber roofing installed over the existing substrate. It is the absolute bare minimum in terms of roofing material for commercial properties. It will prevent water from trickling down through the ceiling of the top floor of your building, but it will probably need to be replaced a lot sooner than most other roofing methods. It is often a base layer for other roofing methods, which is something to consider.
Two Layers: Modified Bitumen
With this roofing method, there is a layer of hot bitumen/asphalt on the wooden substrate of the roof. Before the bitumen/asphalt has a chance to completely cool and harden, a rubberized material is rolled out and stuck fast to the bitumen/asphalt. When it completely hardens and cools, you have a commercial roof that will not leak and is very smooth and easy to walk on (should you need to walk on it).
Three Layers: Structural Metal
Structural metal roofs look more industrial, but there has been a shift away from the corrugated look to something more decorative and attractive in recent years. There is a felt roofing paper placed over the substrate, which is often followed by a rubber underlayment to make the roof really waterproof. Over the top of that, the metal roof is installed. Commercial property owners like the metal roof for its longevity, durability, waterproofing, and sturdiness.
Four to Five Layers: BUR, or Built-Up Roof
This is typically the type of roof most commercial property owners think of or imagine when talking about commercial roofing materials. It starts with a layer of roofing fabric, followed by a layer of bitumen, followed by another layer of roofing fabric, followed by another layer of bitumen, and then topped off with gravel. To save time and money, you can opt for just three or four layers, with three layers being the least possible amount of materials and labor costs you can get away with and still come out with a good roof.
Reach out to a commercial roofing service for more information.