What does single-ply roofing mean?
Single-ply roofs are available in 3 different materials, TPO, PVC and EPDM. TPO stands for thermos plastic olefin. PVC stands for polyvinylchloride and EPDM stands for ethyl propyl diene monomer. TPO and PVC materials are commonly used in Arizona. EPDM was rarely used in Arizona due to its color being black (not a good roof color choice in Arizona), but recently EPDM has become available with a factory applied white over-coat and may become more widely used. TPO and PVC come in a variety of thicknesses. They are very rugged membranes, with very high SRI (solar reflective indexes) and come in many widths which helps to reduce the number of seams on the roof and therefore less potential for leaks. Single-ply membranes are one of the very best low sloped (1/4 inch per ft) roof systems available in the market place today. The initial cost of installation is slightly higher than other flat roof products but when lifecycle costs are evaluated it is actually a less expensive roof.
What is a Flat Roof? The Proper Terminology is Low-Sloped Roof.
A Flat Roof is actually called a low sloped roof. That is a roof with a pitch that is a minimum 1/4 inch per ft and commonly used on structures with low sloped roof designs or porches and patios. For roof slopes that are truly flat or don't meet the minimum 1/4 inch per ft pitch, a tapered system design would be required to create the 1/4 inch per ft minimum to ensure properly water drainage off the roof. For roof slopes that are truly flat or don't meet the minimum 1/4 inch per ft pitch, a tapered system design would be required to create the 1/4 inch per ft minimum to ensure properly water drainage off the roof.
How long does a Single-ply roof system last?
The most common 60 mil thickness membrane will last around 30 years.