ELASTOMERIC ROOF

In the Comments stream of another Post Elaine put "Elastomeric Roof" on her wish list.

My Bona-Fides on this subject derives from the fact that I am President of Greenbrier C and more importantly, we have this type of roof on our building.
I have done a great deal of research of this issue.

There are many issues to consider before making this selection.

Let's start with a bit of Chemistry:

The principal source of Elastomeric Membrane (EM) is the JP Stevens Company of Holyoke Mass.

See: http://www.stevensroofing.com/

The EM is a proprietary Thermoplastic Polyolefin
(TPO) compounded from Ethylene & Propylene.

(wow! glad I took a minor in Chemistry)

JP Stevens calls their product; Hypalon.

Stevens Hypalon® is ideally suited for commercial, industrial and institutional applications, especially where strong chemical resistance is required. The material is available in white and light gray (special order), nominal 45 mil (1.14 mm) and 60 mil (1.52) thickness in standard 76.5-inch wide rolls x 100-feet long (1.9m wide x 34m long).

The strips are hot air welded in place during installation.

Do your Due Dilligence the delta in thickness and the methods of attachment are critical; they relate to warranty duration and wind tolerance. Warranties run from 5 years and 70 MPH up to 20 years and 150 MPH.


In 1975, the company (then part of
J. P. Stevens & Co.), entered the pond
and pit lining business with a reinforced,
Hypalon®-based containment
membrane. A few years later,
Stevens began manufacturing commercial
roofing membranes under private
label agreement.

Today, Stevens Roofing Systems is
a business unit of JPS Elastomerics,
with nearly 140 years of combined
rubber compounding experience.
Stevens Roofing membranes are
marketed in nearly 60 countries
around the globe and more than 1.5
billion square feet of Stevens membrane
has been installed worldwide.

In addition to commercial roofing, the
company is a worldwide supplier of
geomembranes.

The actual installations are done by local franchisees. Only JP Stevens certified installers may install and maintain the EM Roof if your Warranty is to apply.

Let's look at our experience here in Greenbrier.

The combined effects of Hurricanes Francis and Jeanne left the Greenbrier C 14 year old roof in shards on the Golf Course.

I was not on the Board that decided on the EM roof; the appropriate Due Dilligence was not done;
they opted for a 45Mil membrane the final installation carries a warranty of 15 years for maximum winds of 70 MPH, while the duration is fine, the 70 MPH limit is egregiously low for our Florida Hurricane zone. Such winds can be experienced in a bad thunderstorm.

The total cost including the moving and re-installing of 56 Air Conditioner compressors was $150,000.00. The AC component, including upgrades to Code accounted for $25,000.00. of the total..
(look to your Roof Reserve lines)

The Greenbrier roof is a flat roof of approximately 19,000 Square feet in area and is NOT pitched to Code; Current code for a flat roof in Palm Beach County is 1/8th. inch drop for every 12 inches of run. Our roof is 55 feet wide which would require a drop of 6.875 inches from front to back. The actual slope is essentially zero and this leads to ponding when it rains. Therein lays a tale!

About one year after the installation of our EM roof we experience heavy deposits of crinckled black substance on our Catwalks. This material is dirty and readily tracks into ones apartment and is difficult to clean up.

research indicated that this was some sort of Roof fungus; I consulted the State Environmental Biologist in Tallahassee who sent a Technician to investigate. The verdict Algae! The mechanism, simple; the ponding water is warm and wet, the air is full of Algae Spores. They settle in the ponds and grow explosively, until the pond evaporates.

The resulting dry crust, consisting of principally dead Algae, and unburned particulate material from Jet aircraft exhaust, breaks up and is deposited by the wind onto our catwalks, parking areas and cars!

What enables this incredible circumstance you may ask? Simple; 19,000 square feet of contiguous EM is, effectively a giant airfoil and it is in a continuous state of ripple depending on prevailing wind velocity. I have personally witnessed this effect on our roof.

Inhibiting the growth and distribution of this foul material remains an unresolved problem, under study. JP Stevens will not approve any standard Fungicide/Algaecide for application on the EM.

We are investigating Copper Sulfate solution as a possible answer.

So Due Dilligence includes checking the Pitch of your roof before making a final decision. Ponding is not an option.

What other issues have arisen; Early on and from time to time since; we have experienced leaks in our EM roof.

These took a long time to track down and eventually were ascribed to Air Conditioner repair Technicians whose normal activities on all other types of roofs would have no effect, but on our EM roof were anathema. Activity such as setting a new Compressor unit on the Membrane can easily puncture it, sparks from welding readily melt Micro-holes in the Membrane.

So, all Technicians must be warned and monitored.

Additionally special "Walk and Work" strips are available which are now installed in front of every Air conditioner stand to allow the Technicians to work without damaging the roof.

Finally; to maintain the high state of white reflectivity a method of cleaning the EM roof must be developed.

JP Stevens approves Tri Sodium Phosphate and pressure washing at settings not to exceed 200 PSI; this is expensive business but is part of the care and feeding of the EM roof.

So, now the choice is yours; I believe that one other Association in CV has this roof, one of the
Southampton buildings, so you might consult them as to their experience.

I will gladly answer any questions you may have.