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Modified Bitumen Roofs

Modified Bitumen roof systems are asphalt based and provide superior waterproofing characteristics. The typical life span for these systems is about 10 to 20 years. Modified Bitumen roofs are usually installed as a two ply system and are always fully adhered. These roof systems are made up of asphalt that has been modified with a polymer to create plastic or rubber like properties. The modifiers provide increased resistance to brittleness, cold temperatures and increased elasticity and strength. The most common modifiers are APP (Atactic Polypropylene) and SBS (Styrene Butadiene Styrene).

APP modifier, when added provides a plasticized quality to the asphalt. By adding 30% APP, the asphalt is able to be stretched up to 50% of its original length. The APP modified asphalt is reinforced with a polyester mat and manufactured into a roll product. These membranes have extra asphalt on the back side which allows it to bond to the substrate through applications such as heat welded or torch applied methods.

SBS modifier when combined with asphalt, produces rubberized properties. By adding 10%-15% SBS to the asphalt it is then able to be stretched six times its normal length and then can return to its original size once relaxed. This helps deal with the stresses of normal expansion and contraction of a roof. Reinforcements for SBS modified asphalt include fiberglass, polyester, or a combination of both. These membranes are most commonly applied with hot asphalt or cold adhesive. There are also self adhering SBS membranes, which contains an adhesive backing.

There are numerous surfacing options for APP and SBS modified roofs including factory applied mineral surfaces, gravel surfaces, smooth surfaces, and “cool roof” coatings, which are highly reflective coatings that can help save on cooling costs.

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Peak Performance
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To give our customers the best roofing products and workmanship value that can be found anywhere in the roofing industry in the Midwest.

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Over 20 Years
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Peak Performance is a full-service contractor, specializing in most types of residential and commercial roofing.

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