Flat Roofing Materials – Single Ply and Rolled Roofing for Low-Slope Roofs

In this second part of our Roofing Materials Guide, we will go over materials made specifically for low slope applications, where traditional roofing materials will not work.

In this guide, we will discuss two types of flat roofing materials – single ply membranes and built-up roofs.

Single Ply Membranes – EPDM Rubber, PVC and TPO

The name says it all – single ply roofs consist of just one layer, which is a weathering surface and a waterproofing layer all-in-one, unlike built-up roofs, which consist of multiple layers. The most common types of single ply membranes are Rubber (EPDM), PVC, and TPO.

Low-slope and Flat Roofs

IB Flat Roof – A premium grade PVC single ply membrane that uses fusion hot-air welding to adhere separate sheets of membrane together and to create permanent seams. An IB roof provides long-term protection for low-slope and flat roofs, and is perfect for any type of roof penetrations / obstructions. A fully weldable set of accessories includes: Inside and Outside Corner flashings, 7 different  standard sizes of pipe flashing, ranging from 1/4 inch to 1 + foot in diameter, multiple types of roof drains, wall scuppers and overflow protection drains with back flow prevention. An IB roof also features PVC coated drip-edge metal, to which the main roof can be welded.

The entire system is welded together, completely eliminating the need to use adhesives. The only reason this roof can leak is due to installation error, which is easy to fix with the re-welding of the seam. Any physical damage can also easily be repaired by cleaning the damaged area with warm water, or acetone, when extremely dirty, and simply welding a patch over it.

Life expectancy of an IB roof is 30+ years. The system has been on the US market for 32 years and most original roofs are still in service. Therefore, at this point we cannot say for sure whether the roof will last 35 or 40 or maybe even 50 years. Time will tell.

IB Roofs are also COOL Roofs – the main color of IB membranes is white and it also includes special “cool roof” pigments to reflect more solar heat. That’s why you will see energy saving next to IB roof in the roofing calculator results.

EPDM Rubber – It is basically wide sheets of single-ply rubber glued to the roof insulation below it, and overlapping seams are also glued together. A major problem with rubber membranes is the fact that they leak – a brand new roof can start leaking as soon as in 5 years.

EPDM Rubber is less expensive than PVC (such as an IB roof described above) and TPO roofing (which is supposed to combine the low cost of EPDM with hot-air welded seams of PVC). This is why it is immensely popular with contractors, who DO NOT specialize in flat roofing. Despite being very “popular”, rubber roofs pose certain problems for home and building owners, which become apparent only a few years into life of the roof. The seams and flashing of rubber roofs become loose, as rubber glue fails, and leaks start coming in. At this point, the membrane requires some repairs and maintenance (in some cases, repair can be very extensive and costly).

Leaking Rubber Roof

Besides rubber’s inherent problems, you also have to be aware of residential roofing contractors wanting to install this product for you. They usually have very limited knowledge of flat roofing and when they install an EPDM roof, there is a high chance it will leak pretty soon. Moreover, its likely that your contractor will be unable to eliminate the leaks. This will resulting in prolonged damages and increased costs of repair, as now you will have to hire a specialist to repair or replace your rubber roof.