EPS roof insulation has been in use for over 35 years in both new and remodeling construction. This lightweight foam insulation comes in either tapered or direct-to-deck panels, both of which are available through Tri State Foam's Enviro Plus line of EPS products.
In addition, Enviro Plus EPS insulation is compatible with all commercial roofing systems and can be used with built-up roofing, modified bitumen systems and single-ply systems that are ballasted, mechanically fastened or fully adhered.
Benefits of Using Enviro Plus
The advantages of using Enviro Plus EPS insulation in roofing are startling:
Constant R-Value
- Consistent thermal performance over the life of the roof
- Measurable energy savings
- Lower cost per R-value than most other insulations
Outstanding Performance
- Dimensional stability
- Compressive strength
- Moisture, mold and sound resistance
Design Attributes
- Design flexibility and versatility in meeting project-specific applications
- Compatible with all roofing systems and methods of installation
- Works well with common roof assembly components
Environmental Benefits
- Often made from recycled EPS
- Never manufactured from ozone-depleting gases, such as CFCs or HCFCs
- Lightweight and less material required to meet R-value standards
EPS Roofing Products
There are two types of Enviro Plus EPS roofing products: tapered EPS insulation and direct-to-deck EPS insulation.
Tapered Roofing Systems
Poor drainage on commercial roofs often does more damage than the effects of either wind or other natural elements. A build-up of pooled water and freeze-thaw cycles are extremely damaging to most roofs and are very expensive to fix or replace.
Using a positively-sloped roof system will result in reduced maintenance and less stress on the structure as a whole. A tapered roof in both new and replacement construction will channel any water to the proper roof drain. In new construction, this can be achieved by designing a slope into the structure of the building. For an existing roof, the easiest way to improve the slope is to add insulation underneath the membrane. The thickness of the insulation is varied to create the necessary slope.
That is where tapered EPS insulation works best.
By using tapered EPS, you are utilizing a cost-effective choice in low-slope roofing systems. It gives the roof the desired positive slope to move water to the drains while retaining the structural and economic advantages of a flat roof deck. At the same time, it maintains the long-lasting thermal performance, dimensional stability and consistent moisture-resistance characteristic of EPS.
Direct-To-Deck EPS Roofing Applications
Enviro Plus EPS insulation can be applied directly to steel roofs without a thermal barrier in single-ply membrane roofing systems.
This type of EPS insulation is a very cost-effective, durable and energy efficient solution. It is also compatible with all major roofing materials and assemblies and comes in flat, tapered and compound tapered panels in a range of densities.
EPS insulation's thermal and mechanical properties are ideal for commercial and industrial applications where R-value and moisture resistance are paramount. Its energy efficiency, strength, dimensional stability, design flexibility and resistance to natural forces, not to mention its ease of installation, make EPS the preferred choice of many roofing contractors.
EPS Roofing Membrane Systems
Enviro Plus EPS insulation products work very well with all three different types of roofing applications: Built-up, modified bitumen and single-ply.
Built-Up
Built-up roofing (BUR) systems have been in use for more than 100 years and account for roughly 20 percent of all new low-slope roofing construction projects and 21 percent of re-roofing jobs. EPS has been used in this roofing application for more than three decades.
BUR systems constructed with a concrete roof deck allows the roof insulation to be applied directly to the deck as there is no requirement for a thermal barrier due to the presence of the noncombustible concrete deck.
The EPS foam may be adhered to the concrete with asphalt using a technique described as "mop and flop" by the roofing industry. Hot asphalt is applied to the concrete deck and allowed to cool slightly before the foam is permanently dropped into place. A coverboard is then "mopped and flopped" onto the EPS with the joints overlapping and taped. The BUR is then applied on top of the coverboard, which provides a uniform and consistent base for the weatherproofing system.
When using a steel deck, building codes require a thermal barrier with an index of 15, such as 1/2 inch gypsum board. The required barrier protects the foam from ignition as well as limiting the potential contribution to under-deck flame spread during a fire by the roofing system components. It is necessary to place a coverboard above the foam to protect it from hot asphalt used to adhere and build up the waterproof protective roof covering materials.
EPS foam used in BUR systems can be installed as described above or may by delivered to the job site as a complete composite panel that would include the thermal barrier, when necessary, the insulating foam and the coverboard. This composite panel can then be easily adhered or mechanically fastened to the concrete or steel deck, saving on-site labor.
The use of prefabricated composite panels for BUR roofing applications has been steadily growing because of the labor savings involved in installation.
Modified Bitumen
Polymer-modified bitumen membrane systems have been used in the United States since the mid 1970s and account for approximately 18 percent of all new low-slope construction and 23 percent of re-roofing applications.
These membranes are available in either asphalt or coal tar-based systems that have been modified with a polymer and reinforced with a variety of materials including glass fiber, polyester or polyethylene. They can be installed with torches, in hot asphalt, cold adhesives, and/or self-adhered and sometimes in combination with hot-air welders. EPS insulation used in modified bitumen roofing systems should be handled and installed similarly to BUR systems and will require thermal barriers and coverboards.
Single-Ply
Single-ply membrane roofing systems account for just over 40 percent of all new low-slope construction and about 32 percent of re-roofing.
These systems are factory-manufactured roof coverings, in contrast to BUR membrane systems that are constructed on the roof from bitumen and reinforcing fabric materials.
Typical membrane thicknesses range from 30 to 60 mils, with 1 mil equal to 0.0001 inch; however, greater thickness can be produced depending upon the manufacturer and product type.
Single-ply, thermo-plastic membranes will soften when heated and harden when cooled while thermo-set membranes are irreversibly set and will not soften when heated. Because of these fundamental differences, single-ply membranes may be installed in the following ways:
- Ballasted
- Mechanically Attached
- Fully Adhered
Enviro Plus EPS insulation can be mechanically fastened or fully adhered directly to a concrete roof deck with no thermal barrier, and depending upon the membrane, the installation system may or may not require a coverboard.
Ballasted systems may not need a coverboard, whereas mechanically attached or fully adhered membrane systems typically will require a coverboard to provide additional strength for attachment fasteners or to act as a barrier to harmful petroleum vapors released from membrane sealing adhesives.
EPS insulation is available in thicknesses up to 40 inches, typically with square edges. It can be tapered to 1/8 inch per foot to allow for adequate drainage on structurally flat roof decks. Typical thicknesses for roof applications are up to 12 inches. EPS insulation is available with a variety of compressive and flexural strength properties.
