About flat roofing from Dunn Contracting
Modified Bitumen
Modified Bitumen or “modbit” membranes consist of an asphalt and polymer blend which allow the asphalt to take on characteristics of the polymer. There are several surfacing option for this system which include a factory applied mineral surface, a gravel surface laid in bitumen or a liquid applied coating that is typically reflective in nature. Typical lifespan of a modified bitumen roof is 10 to 20 years depending on weather conditions. Modified Bitumen: These are the "creme de la creme" in the asphalt applications. Such products are upgraded with SBS rubber additives ensuring physical endurance through better expansion, flexibility, higher fire rating and self-sealing options. Modified Bitumen can be installed with traditional hot asphalt or cold applied adhesives. Be sure to ask about Modified Bitumen upgrades when your next roof is installed.
Tapered Systems
Flat roofs are very common in Florida. Older flat roofs have a tendency to pond water following the rain. Florida law now requires installation of tapered insulation if a flat roof ponds water for more than 48 hours. A roof should slope no less than 1/4" vertical to 12" horizontal. Ponding water can cause a breakdown of your flat roof materials leading to leaks and other roofing problems.
One of the obvious benefits of installing a tapered roofing system is that the slope created will allow water to runoff. Just a slight slope can prevent water from ponding. The construction of the isoboard adds insulation to the roof, which can lower your energy bills and add longevity to the life of your roof.
Essentially they work as follows:
Insulated panels are placed below the membrane or final roofing solution to create slopes in the roof. Design plays an important role in the process of adding a taper system. Proper installation is essential to the system working and avoiding future problems with the roof. Poor drainage on residential roofs can result in damage far more destructive than either wind or other natural elements. Homeowners often under estimate the advantages of tapered roofing when evaluating the life expectancy of a roof.
Positive drainage is necessary to insure a safe, long lasting roof. Ponded water can result in costly repairs and even pre-mature roof failure, which is rarely covered under warranty or by insurance. Positive sloped roof systems result in reduced maintenance and less stress to your homes structure.
Tapered roof insulation is an excellent way to both help insulate flat roof decks as well as provide positive drainage. Applied directly to the roof surface, tapered roof insulation can prolong the life of the roof by assisting in the drainage of any collected water, as well as helping to eliminate any potential weight or load bearing issues.
