Thread: IRMA roofing system
11-03-2000, 03:41 PM #1Matt Guest
IRMA roofing system
does anybody have any experience with an IRMA roofing system? What is it? What are the pros/cons of this system? Any help would be appreciated! thanks.
12-05-2000, 10:06 AM #2Bill Guest
Re: IRMA roofing system
IRMA stands for Insulated Roof Membrane Assembly.
Irma roof systems are typically used on commercial and large scale residential structures with flat roofs. They have the insulation ontop of the roof membrane, not below it. The insulation is weighted down by ballast, ie: gravel and/or paving stones.
Since the added weight of the gravel is so heavy it is really not used in wood frame construction, especially when you can insulate between the rafters, or in the ceiling.
The Pro's of the system are that the roof membrane is protected from ultra violet degradation by the insulation and ballast, and its also is protected from thermal shock by the insulation. The roof is also protected from pedestrian traffic by the ballast. This supposedly extends the life of the roof system. These roofs can be installed with single ply as well multiple ply roofing membranes.
In our experience these roofs typically do not have a greater usefull life than a more tradition flat roof system, usually from poor installation details. Since the membrane is covered, it is very dificult to track down and repair leaks. Because of the weight of the ballast the roof structure has to be stronger and therefore more expensive.