Residential Roofing: Flat
Built-up Roofing is one of the oldest and most reliable methods of roofing. It was first known as composition roofing and started in the 1840’s. Built-up roofs are exactly that, they consist of several (as many as six) plies of roof felt laminated in hot asphalt, and surfaced with Gravel set in a flood coat of asphalt.
Many different types of materials with different qualities are available. This variety of materials allows the qualities of the roof to be tailored to the specific requirements of the structure. Built-up roofs can be installed on virtually any type of roof deck. Some of the benefits of a Built-Up roof are:
- The multiple plies create terrific protection against leaks.
- The flood coat and gravel surfacing provide impact resistance and UV protection.
- Extreme resistance to wind uplift.
Modified bitumen roof systems have expanded their share of the commercial roofing market in recent years. Atactic Polypropylene (APP) and Styrene Butadiene Styrene (SBS) modified bitumen membranes comprise about 60 percent of the commercial roofing market. The growth of modified bitumen roof systems is likely due to many factors, including:
- Familiarity in the marketplace – modified bitumen’s were introduced in the U.S. in 1972
- User friendly – many contractors can use their existing built-up roofing equipment and expertise
- More economical – modified systems are generally less expensive than Built-up systems
Like Built-up roof systems, Modified roof systems consist of several (usually 2) plies of roof felt laminated in hot asphalt, but with a cap sheet that is covered in ceramic granules. Many different types of Modified roof systems are available that offer a range of qualities. This variety of materials allows the qualities of the roof to be tailored to the specific requirements of the structure. Modified roofs also can be installed on virtually any type of roof deck. Some of the benefits of Modified roofs are:
- Lighter Installed Weight Over Built-up
- Energy Star Compliance.
- LEEDS Credits
- Quick Install Time
- Multiple Color Options
EPDM has been in use on roofs in the US since the 1960’s and is one of the most common types of flat/low-slope roofing materials. This is because it is relatively inexpensive, simple to install, and fairly clean to work with when compared to conventional Built-up roof systems. The odors and fumes that accompany built-up roofs are not present with single ply systems; this is very appealing to many owners of buildings.
There are three standard application procedures of EPDM:
Fully-adhered EPDM uses water or solvent-based adhesives to adhere the rubber to the substrate. Mechanically-fastened EPDM is attached by manufacturer-approved mechanical means to the substrate, and loose-laid membranes are secured only at the perimeters and any penetrations.
TPO membranes are single-ply roof membranes constructed form ethylene propylene rubber. They are designed to combine the durability of rubber with the proven performance of hot-air wieldable seams. They have been tested as having excellent resistance to ozone, are algae-resistant, environmentally friendly and safe to install.
The material’s manufacturers are so confident in properly welded seams that the material is sometimes advertised as a monolithic (seamless) roof. Seam strengths are reportedly 3 to 4 times those of EPDM’s adhesive and tape seams. TPO is highly resistant to tears, impacts, and punctures with good flexibility to allow for building movement.
TPO’s are most common in white; however, many more colors are available, with mils thicknesses of 45 (.045”), 60 mils (.060”), or 80 mils (.080”). The width of the membrane depends on the manufacturer but they usually come in widths of six to six-and-a-half feet and are one hundred feet in length. TPO is the most common single-ply system.
PVC membrane is a roof membrane composed on only one layer of material, polyvinyl chloride. PVC roof systems are specially designed to withstand ponding water – PVC membrane is welded together with hot air (no open flame) to eliminate all seams so moisture cannot pass through, just like TPO systems. PVC roofing systems also reflect nearly 90% of the heat of the sun, thus lowering energy costs substantially, especially in high-heat areas such as the southwestern United States. PVC’s are available in 50 mils, 60 mils, and 80 mils, and in sheet width up to 78”.
As a property owner or manager, there are situations when you must have a
new roof. Yet, there are other situations when options are available to use liquid-applied coating systems that can extend the existing roof’s life, with a WARRANTY.
Sargon Construction Corp. offers a complete product line of coating systems that can virtually be applied to any type of existing roof surface. Coating systems form a durable, continuous membrane over the existing surface of the roof, forming a seamless, watertight seal over the entire roof, including all penetrations. Some of the benefits are included here:
- Versatile – Formulated to restore virtually all type of existing roof systems
- Proven – Millions of square feet of coatings applied each and every year
- Conserves Cash – Can save up to half the cost of a new roof—while adding up to 20 years of life to your existing roof
- Energy Savings – Reflective white surface can save energy—up to 50% or more of the roof’s original cost
- Guaranteed – NDL warranties can be given up to 20 years.
Call us today at 847-422 3931 for a FREE, no obligation inspection and estimate.