This is a public Blog  publicRSS

Entry

    Chuck McClain
    Roofs you don't want to find on the building...
    Entry posted March 22, 2010 by Chuck McClainContributor , last edited March 22, 2010
    6124 Views, 1 Comment
    Title:
    Roofs you don't want to find on the building...
    Entry:

    When conducting an assessment of the building, we all know to ask the site contacts about the presence of roof leaks, to look for signs of water damage on upper floor ceiling panels, and to look for obvious signs of damage or potential water entry paths on the roof.  In addition, if the building has a single-ply thermoplastic roof membrane, it is imperative to identify the manufacturer and membrane type.  We have seen more and more fairly subtle but important deficiencies with the following roof types:

    1. Ethylene Propylene (EP) and Hypalon Roof Systems manufactured by J.P. Stevens.  J.P. Stevens has experienced problems with their EP and Hypalon membrane roof systems.
    2. PVC Blend membranes manufactured by Duralast.  We have seen numerous failures of these systems, especially in “Hail Belt” areas.
    3. Thermoplastic Polyolefin (TPO) and PVC membranes manufactured by Genflex.  Genflex has experienced numerous problems with their TPO and PVC membrane roof systems.  If your property has a Best Buy store, it is likely that there is a Genflex TPO installed. 

    Of these, we’ve probably seen EP roof membranes more frequently than the others.  These membranes are reinforced with a polyester scrim (mesh).  The problematic roofs typically were installed in the late 1990’s and include both black and white membranes.  Once the roof gets to the six or seven year mark, it is likely that leaks have started occurring.  There are two types of deterioration frequently seen in an EP roof membrane: 

    1. Seam Edge Splitting. This is considered the worst type of deterioration, occurring on either side of the seams in the roof.  The splits are first seen as hairline cracks at the edge of the lap, which may only be through the top side of the membrane.  The splits can initially be difficult to find, although once the membrane is split all the way through they become more obvious.  The splitting can be anywhere from one inch to over 100 feet in length, and sometimes alternate between splitting and hairline cracking and back to splitting again along the same lap area.  If you see black EPDM cover tape over the laps between membrane sections, it is likely these repairs are mitigating leaks resulting from seam splits. 
    2. Membrane Flaking.  This can be a challenge to identify since the flaking can be very small (such as 1/16th of an inch around), or as large as two inches in diameter.  With this deterioration, the scrim is rarely broken (as opposed to physical impact damage where the scrim is typically destroyed) although if the condition has existed for a long time the scrim may be damaged or broken from the weather.  You’ll notice that the top of the deteriorated membrane can usually be chipped up in small pieces.  This flaking can quickly spread over large areas once it starts.  Observing the flaking deterioration is easiest after the morning dew or after a rain, when the water is wicking back through the membrane.

    The result of this type of deterioration are roof leaks, and all that they can bring to a building environment: from unhappy tenants complaining about the roof leaks, safety issues resulting from slip hazards to microbial growth, roof framing deterioration and eventual roof failure. 

    Identification of these roof systems is important in both debt and equity scenarios.  Lenders need to know of the shorter expected roof lifespan and equity interests will most likely get a reduced price for the asset with these defective membranes.  Identification of these systems is important and if we see splitting or flaking, the prudent course of action is often recommending further review of the roof by a qualified roofing consultant.  In some cases, the manufacturer will replace the roof at no cost to the owner. 

    Image:
    Keywords:
    roofing, single ply, EP, TPO, Hypalon, PVC

    Comment

     

    • omd

      Dead on in my opinion. So true, I have seen and repaired over 1000 roofs with these listed problems. Many Lowes and Wal-Marts, in Louisiana  and Texas here in the south have these roofs with these issues. Fairly easy to find and repair. Lead to some very large leaks. First article I've seen cover it.

      Thanks again -