Hypalon Roof Challenges in Florida

July 15th, 2012 • By: Rick Brown Roof Types, Uncategorized

Approximately 25 years ago, and as an adjunct to its use as a reservoir and pond liner, DuPont introduced Hypalon as a roof membrane. The rationale was its’ superb resistance to chemicals and long-life in harsh environments made it an excellent candidate for a roof system.

Hypalon is synthetic rubber and is chemically formulated as chlorosulfonated polyethylene (CSPE). As a roof membrane, Hypalon is welded with hot air as a thermoplastic. Subsequent to installation and environmental exposure, the membrane’s components cross link to form a synthetic rubber material. The membrane is dimensionally stable to +/- 0.1% after cure and has reflectivity and emissive ratings of .85 and .87 respectively. White Stevens Hypalon membranes meet the EPA Energy Star Roof Products requirements and are California Title 24 compliant.

Hypalon membranes are installed in a variety of fashions, however, the primary methods are fully adhered and mechanically attached. Because of its’ impervious nature to most chemicals, Hypalon is available as a direct installation over the following roof systems:

  • Smooth surfaced, aged coal tar pitch and built-up asphalt
  • CPE
  • EPDM
  • Modified bitumen

Additionally, Stevens Hypalon has wind ratings ranging from 1-90 for mechanically attached to 1-270 for fully adhered and has both UL and Factory Mutual Class A fire ratings.

Several issues over the years have caused the Hypalon market share to decrease dramatically. Foremost is the growth of red algae on the membrane surface prior to complete cure. Red algae causes human health concerns and promotes other vegetative growth which ultimately destroys the membranes watertight integrity. The secondary problem with Hypalon membranes is “chalking and cracking” caused by UV exposure. This chalking leaves the membrane in an almost irreparable state necessitating the development of special primers and dual installation to install a patch or repair a seam. The final issue is that of shrinkage, more prevalent in the non-reinforced membranes. Stevens attempted a change in formulation in the late’80s to address these issues, however, it was relatively unsuccessful and with the advent of other PVC and TPO hybrids, the market appears to have moved on.

SRC stocks Hypalon membranes and primers required for repairs. If your Hypalon roof needs maintenance or corrective measures, please feel free to contact us.

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Approximately 25 years ago, and as an adjunct to its use as a reservoir and pond liner, DuPont introduced Hypalon as a roof membrane. The rationale was its’ superb resistance to chemicals and long-life in harsh environments made it an excellent candidate for a roof system.

Hypalon is synthetic rubber and is chemically formulated as chlorosulfonated polyethylene (CSPE). As a roof membrane, Hypalon is welded with hot air as a thermoplastic. Subsequent to installation and environmental exposure, the membrane’s components cross link to form a synthetic rubber material. The membrane is dimensionally stable to +/- 0.1% after cure and has reflectivity and emissive ratings of .85 and .87 respectively. White Stevens Hypalon membranes meet the EPA Energy Star Roof Products requirements and are California Title 24 compliant.

Hypalon membranes are installed in a variety of fashions, however, the primary methods are fully adhered and mechanically attached. Because of its’ impervious nature to most chemicals, Hypalon is available as a direct installation over the following roof systems:

  • Smooth surfaced, aged coal tar pitch and built-up asphalt
  • CPE
  • EPDM
  • Modified bitumen

Additionally, Stevens Hypalon has wind ratings ranging from 1-90 for mechanically attached to 1-270 for fully adhered and has both UL and Factory Mutual Class A fire ratings.

Several issues over the years have caused the Hypalon market share to decrease dramatically. Foremost is the growth of red algae on the membrane surface prior to complete cure. Red algae causes human health concerns and promotes other vegetative growth which ultimately destroys the membranes watertight integrity. The secondary problem with Hypalon membranes is “chalking and cracking” caused by UV exposure. This chalking leaves the membrane in an almost irreparable state necessitating the development of special primers and dual installation to install a patch or repair a seam. The final issue is that of shrinkage, more prevalent in the non-reinforced membranes. Stevens attempted a change in formulation in the late’80s to address these issues, however, it was relatively unsuccessful and with the advent of other PVC and TPO hybrids, the market appears to have moved on.

SRC stocks Hypalon membranes and primers required for repairs. If your Hypalon roof needs maintenance or corrective measures, please feel free to contact us..

PVC Roofing Overview

June 9th, 2012 • By: Rick Brown Roof Types

A secondary roof membrane to be available on the market was introduced in Europe in the 60’s. PVC, another thermoplastic membrane available in a variety of thickness’, has been installed in the US since the 70’s and has found an increasing market share since that time.

PVC is specifically polyvinyl chloride and is formed into membrane with the addition of oils or liquid plasticizers. In roofing membranes, PVC is available in “bare” form or with the addition of fleece backing. PVC has a superior resistance to ponding water and chemical resistance is high. Additionally, many PVC roof membranes such as Sarnafil, qualify as Energy Star rated for reflectively and meet the EPA and DOE energy savings specifications. Most PVC membranes can be formed in a spectrum of colors allowing for a metal panel “look” or the addition of logos or multi-colored systems.

As with most single-ply membranes, PVC is attached mechanically through insulation, direct to substrate, or may be fully adhered. With the addition of fleece backing materials, PVC can be fully adhered over rougher finishes or mopped with asphalt. The laps are made similarly to TPO or CSPE membranes by using robotic or hand-held welders that force heated air into the laps and fuse them together in a semi-molten state. These laps are then rolled as part of the electric welding process, yielding one continuous membrane.

Two significant problems with PVC membranes have appeared over the years. The first is plasticizer migration. This causes the membrane to embrittle, shrink and become a candidate for shattering, especially in cold weather. Many of the oils and liquids initially used in fabrication exhibit this trate and shattering at 22 degrees Farenheit is documented. If this occurs, it is mandatory to re-roof immediately since there is no way to re-establish the plasticizer content. The addition of polymers such as Elvaloy is Sarnafil and Fibertite membranes and the use of reinforcement fiberglass or polyester fibers have addressed this problem.

The second problem is that PVC manufacture and its’ components are inherently environmentally unfriendly. Accounting for nearly 40% of the worldwide chlorine production, PVC also produces biohazards at almost every stage of the life cycle from fabrication – disposal. Numerous nations and communities have PVC avoidance policies which extend to roof membranes.

To discuss preventive measures or inspections of your PVC roof, please contact All Area Roofing. One of our specialists will be glad to help you.

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EPDM Roofing Solution for High Square Footage

February 20th, 2012 • By: Rick Brown Uncategorized

Since the 1960’s, an increasing number of manufacturers, building owners and contractors have searched for an alternative to the fumes, flame and expense of conventional “hot applied” roof systems. One of the original single-ply systems to provide that alternate is a synthetic rubber known as EPDM.

Ethylene Propylene Diene Monomer or EPDM, is a compound whose principal components are ethylene and propylene. This form becomes a flexible rubber when diene is added. EPDM is classified as a thermoset membrane, meaning it is cured prior to installation. The uncured form is used as flashing material and cures during the natural weathering process. Seams are chemically welded with solvent borne adhesives or specialty seam tapes with adhesive primers.

One of the early appeals of EPDM was the relatively low materials cost. The membrane is typically 25 per cent-30 percent less expensive than modified bitumen and half the cost of built-up roofs. The uncured flashing materials and lap adhesives tend to drive the price higher, however the overall cost can be considerably less than conventional roofs and this is especially attractive for large scale distribution centers or manufacturing plants.

Three choices are available in EPDM system design:

  1. A mechanically attached system with fasteners through the laps and into the substrate;
  2. A fully adhered system glued to either suitable insulation or substrate and
  3. A loose laid or ballasted system, fastened only at the perimeters and penetrations with either pavers or stone holding the system in place. As of the revised 2004 Florida Building Code, system 3 is no longer applicable in the state, but is used extensively in large facilities requiring less stringent wind uplift standards due to its extremely low installation costs.

As the early EPDM systems aged, several issues became apparent. First and foremost is shrinkage. Most notable is ballasted systems, shrinking membranes displace gravel, can distort wall or edge flashings and will ultimately tear the membrane itself allowing water intrusion. There are no universal methods of addressing shrinkage as the repairs required range from minor tension relief cuts to complete re-roofing. The second problem is lap failure, often due to shrinkage or improper adhesive installation. The latter problems have been addressed with the advent of seam tapes providing more uniform lap strength.

If your property is currently covered with an EPDM system, please contact All Area Roofing & Waterproofing for a free evaluation with maintenance recommendations..

The Modified Bitumen Evolution in Florida Roofing

January 19th, 2012 • By: Rick Brown Roof Types, Uncategorized

One of the many evolutions in the roofing industry has been the formulation of modified bitumen membranes. As the name implies, modified membranes are asphalt based with modifying polymers introduced during the manufacturing process. The most common modifiers are APP or SBS, which when combined with asphalt, give the resulting membrane plastic or rubber-like properties.

Modified Bitumen RoofingIn addition to providing greater tensile strength and elasticity, the introduction of these polymers allows for a single roll with coverage of 100 square feet, including the surfacing, resulting in significant labor savings during application. Modified can be installed with conventional hot asphalt, modified adhesives, open flame torches, hot air welders or most recently, self adhered. Several of today’s systems, such as Derbigum, combine the superior uplift of adhesives with the immediate watertight lap provided when torching or heat welding.

All modified bitumen membrane rolls rely on an inner scrim or reinforcement mat to hold the asphalt in place. Scrims are typically polyester or fiberglass or both and these mats are dipped into the molten modified mix, processed through a rolling cylinder and then a surfacing table and cooking bath. These mats are chosen because of their ability to accommodate the modifying polymers elongation properties. The type and weight of the mat determines the final characteristics of the roll and ultimately the price.

Since the introduction of modifieds in Florida in the 70’s, their market share has increased steadily culminating in almost 30 per cent in the 90’s. Several factors play a role in the recent decline seen in this market over the last decade. A few of these include:

  • Widespread acceptance of thermoplastic systems requiring minimal slope with accompanying reduced installation cost.
  • Increased insurance costs associated with open flame and 500 degree molten asphalt for SBS cap sheet installation.
  • Rising petroleum costs translating to higher manufacturing prices and ultimately more expensive end user cost.
  • Increased demand for environmentally sensitive “cool roofs” and more awareness of potentially harmful fumes.

Despite the items listed above, modifieds have proven performance on residential, commercial and industrial applications. The granular surfacing requires no costly maintenance coatings while making inspections and repairs very easy. Tough and long lasting, these systems are designed for Florida Owner/Managers that wish to keep and maintain rather than sell..

Build-up Roofs a Longtime Staple for Florida Commercial Buildings

November 16th, 2011 • By: Rick Brown Roof Types

Built-up roofs using coal tar pitch are the oldest form of flat roofing in existence. One hundred forty year old sketches are available showing horse drawn “hot kettles” and this form, with minimal changes, is still in use today in Tampa Bay and all of Florida.

Coal tar pitch is a distillate of coal tar and is formed of primarily aromatic hydrocarbons. This complex linking makes coal tar inherently stable chemically and allows a broad range of softening temperatures vs. the defined melting point found in asphalt products. In short, coal tar is an extremely durable roof membrane which softens at very low temperatures and this cold flow property allows the roof to “heal” itself from minor punctures and voids.

Coal tar roof systems consist of alternating layers of roofing pitch with reinforcing felts and are “built-up” in a similar fashion to asphalt BUR roofs. Because of the unique chemical composition of coal tar, it can be installed on “dead level” or poorly drained flat roofs with no ill effects on the system. Prior to the widespread use of mechanical air conditioning units, many buildings were “water cooled” by providing raised edge details to impede water run-off and coal tar pitch was the roof system of choice for these locations.

Coal tar pitch is also utilized in several other areas of the construction industry including a below grade waterproofing mastic and pavement sealants.

Unfortunately, the past few decades have revealed some serious health concerns with coal tar products. Side effects from the vapors range from minor skin, nose and throat irritation to nosebleeds, changes in skin pigmentation, rashes, fainting and comas.

Additionally, the price of pitch has been a prohibitive factor as the installation cost is typically 2-3 times that of asphalt products and special design criteria must be met to accommodate the cold-flow characteristics.

The combination of health and cost concerns has created a marked decrease in the cold tar market. Several manufacturers’ have vacated this segment of the industry and as health insurance costs continue to rise, we’re doubtful coat tar pitch will rebound.

If you have a coal tar roof on your building and require assistance in managing this specialized system, call All Area Roofing & Waterproofing, Inc. today..