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ROOFING INSPECTION & REPAIR
AMERICAN CEMWOOD ROOFING
BEST ROOFING PRACTICES
BUILT UP ROOFS
CATHEDRAL CEILING VENTILATION
CERTIFICATIONS for ROOFING CONTRACTORS
CHIMNEY FLASHING Mistakes & Leaks
COLD WEATHER ROOF TROUBLE
DECKS, ROOFTOP CONSTRUCTION
EPDM, RUBBER, PVC ROOFING
EXTRACTIVE BLEEDING on SHINGLES
FIRE RETARDANT PLYWOOD
FLASHING on BUILDINGS
FLAT ROOF MOISTURE & CONDENSATION
Green House or Solarium Roof Leaks
HEAT TAPES & CABLES on Roofs for Ice Dams
ICE DAM PREVENTION
MASONITE WOODRUF FIBERBOARD ROOFING
NOISE CONTROL for ROOFS
PLASTIC ROOFING TYPES
PVC, EPDM, RUBBER ROOFING
ROOF ARCHITECTURAL STYLES - PHOTO GUIDE
ROOF CLEANING RECOMMENDATIONS
ROOF COLOR RECOMMENDATIONS
ROOF INSPECTION SAFETY & LIMITS
ROOF LEAK DIAGNOSIS & REPAIR
ROOF NOISE TRANSMISSION
ROOF REPLACEMENT SNAFUs
ROOFING FELT UNDERLAYMENT REQUIREMENTS
ROOFING MATERIALS, Age, Types
SADDLE CONSTRUCTION at CHIMNEYS
SNOW GUARDS & SNOW BRAKES
STANDARDS for ROOFING
STRESS SKIN INSULATED PANELS
TEST LABS - ROOF SHINGLE
TREES & SHRUBS, TRIM OFF BUILDING
TRUSSES, Floor & Roof
UNDERLAYMENT REQUIREMENTS on ROOFS
VENTILATION in BUILDINGS
WALK-ON ROOF SURFACES
WARRANTIES for ROOF SHINGLES
WORKMANSHIP & ROOF DAMAGE
EPDM Roofs, Rubber Roofs & PVC Roof coverings: this article describes membrane roofing materials, flat roof membrane choices, flat roof installations, inspection, EPDM or rubber roof defects, flat roof leak detection, flat roofing repairs, and flat roof membrane product sources.
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Membrane Roofing Materials, EPDM, PVC, or Rubber Roof Choices, Costs, Life Expectancy, Flat Roof or Membrane Roof Characteristics
Also see EPDM ROOF LEAK REPAIRS.
"Membrane roofs" is a general term that may be applied to a low slope or flat roof covered by any means that is intended to produce a continuous waterproof barrier.
Our photo (left) shows roof penetrations and flashing on an EPDM roof in New York. [That chimney may be too short, violating code and safety if it extends less than 2 feet above the roof surface.] Look closely and you can see the marks left by round anchors that tied rooftop insulation to the roof deck below. This telegraphing of insulation fasteners is not a roof defect - it's normal.
Asphalt shingles, in contrast to the EPDM roof shown here, , are not a "waterproof membrane" and depend on the drainage offered by the roof slope to function effectively.
That's why without special measures (discussed at LOW SLOPE ROOFING) we don't expect to find shingles installed on roofs of pitch lower than 4" of rise in 12" of run.
Carson Dunlop's illustrations (below) compare an EPDM roof membrane installation and a PVC roof membrane installation.
Substrates for EPDM Roofs
Installation Details for EPDM Roofs
Pros and Cons of EPDM Roofing
-- Adapted with permission from Best Practices Guide to Residential Construction.
Common Problems in PVC or EPDM Membrane or "rubber" Roofs
As Carson Dunlop's sketch (below) illustrates, wrinkling and failure at seams are problems to watch for where membrane roofs of EPDM, PVC, or similar materials are installed. A wrinkle in an EPDM roof is also shown at the top of this page.
[Click to enlarge any image]
Common EPDM or Rubber Roof Installation or Wear Defects include
Wrinkles in the rubber roof invite future seam failures
Shown during its 1998 installation at left, this rubber EPDM roof was installed on a New York home by a very large and busy Kingston New York roofing company. We followed the life of this roof and its leak and repair history for the ensuing 12 years and describe the results here.
The roofer also may have been in a bit of a rush. EPDM needs to be opened and allowed to relax before it is installed, and care should be taken to minimize the number and size of wrinkles in the roof during the bonding process.
A few small wrinkles in the center of a section of rubber probably won't cause much trouble, but wrinkles near EPDM roof seams are an other story, as we explain here.
Wrong roof edge flashing causes ponding
The use of an improper drip edge (gravel stop on a roof that did not use gravel ballast) can be seen at the left side of our photo.
The gravel stop "edge flashing" was nailed on top of rather than below the rubber roof material in order to allow the rubber to be lapped over the roof edge and extended an inch into the gutters (not shown) - which was not a bad idea, though the roof's success then depends on the seam sealing tape (not yet installed here) to prevent leaks at the flashing nails.
The problem with using the wrong roof edge flashing ( a flat drip edge should have been installed) was the ensuing ponding at the roof edge. In New York where ponding of melting snow later re-freezes, the freeze/thaw action worked open seams near the roof edge, especially where a wrinkle crossed any roof edge seal or seam tape seal.
The EPDM roof shown above leaked in less than five years, and by ten years of age we found recurrent openings and leak risks at several seams in the roof as well as along the lower roof edge where that stupid gravel stop was installed.
Our photos below illustrate what happens when an EPDM wrinkle extends into a roof seam, and as you can see by the water stains, the gravel stop caused excessive ponding that gave frost extra time to work on and push open the seam tape nearer the roof edge. These seam failures (and leaks) began appearing in the rubber roof in less than five years. The photos below show the roof edge at 14 years of age.
At EPDM ROOF LEAK REPAIRS we describe the maintenance & leak history and the ultimate repairs required for this EPDM roof.
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Frequently Asked Questions (FAQs) about membrane type roofs: rubber, EPDM, plastic: installation, inspection, leaks, repairs
Questions & answers or comments about the installation, inspection, properties & repair of EPDM or "rubber" roofs.
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Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.