Protected Membrane Roof (PMR)

Sheppard Pearl Waterproofing

Member of GTHBA, CHBA (Since 2004)

To contact us:

Phone: 416-677-0888

Fax: 416-757-0672

E-mail: info@iwaterproofing.ca

General Information

Protected membrane roof [PMR] was introduced in late 1960s and early 1970s, also called “Upside Down” roof or Inverted Roofing Membrane Assembly (IRMA). It was one of the most innovative roof designs at that time. This roof system was started to develop and market by The Dow Chemical Company, after the birth of STYROFOAM RM (Roofmate) insulation in 1951.

The main concept of PRM system is that the waterproofing membrane is located under the thermal insulation, instead of being applied on top of insulation.

Advantage:

· Maintain roof membrane at almost constant temperature that close to the interior temperature of the building. This will decrease a lot of the stresses on the membrane by reducing the freeze-thaw cycling and excessive heat.

· Protect the roof membrane from weathering and foot traffic.

· Allow year-round construction since the roof is waterproofed first, then insulate.

· Easy remove and re-install the ballast and insulation, which make repair easier.

· Wide range of ballast to choose from: precast concrete paving slab, interlock, stone or gravel.

Install Styrofoam Insulation on a Protected Membrane Roof

Protected Membrane Roof (PMR)

Introduction