A modified bitumen roofing system is popularly used on roofs in Chicago because of its superior quality and ability to withstand the harsh climate. Modified bitumen is a roofing asphalt that is used for flat roofs; it has many layered sheets of fiberglass or polyester that are combined with asphalt for a durable high-strength flat roof. It’s one of the most common low-slope roofing systems. Not to be confused with similar materials like asphalt roll roofing, EPDM, or TPO, modified bitumen combines hot asphalt with plastic and rubber additives. It is the top choice due to its waterproofing feature. A bituminous roof is used to build water & vapor-proof. The flexibility and protection are why it’s so widely used. But in the city, you can’t have modified bitumen membrane roofs without a coating.
DID YOU KNOW? The city of Chicago requires that modified bitumen membrane roofs be aluminum coated to be in compliance. The cost for this service runs between $1.00 – $1.50 per square feet.
Roofing by Hernandez has many years of experience with this type of roof installation. We are also available to perform maintenance, patchwork caulking where it’s needed before coating the roofs.
These are a few typical aluminum coatings that are commonly used.
- 628 Aluminum Coating Utility Grade – Non-Fibrated Provides A reflective surface for roofs, metal buildings, and mobile homes. Formulated from specially refined asphalt, aliphatic solvents, and ASTM D-926
- 608 Aluminum Coating 2 Lb. – Non-Fibrated A reflective surface for roofs, metal buildings, tanks, and mobile homes. Formulated from refined asphalt, aromatic and aliphatic solvents, and 2 lbs per gallon of ASTM D-962 aluminum paste.
- 648 Aluminum Coating 3 Lb. – Non-Fibrated The difference is that it uses refined asphalt, aliphatic solvents, and 3 lbs. per gallon of ASTM-962 leafing aluminum paste.
The Lucas brand is the one we use most often. They specialize in coatings and mastics for the roofing trade.
Any waterproof flat or low slope roofing has three main sections which include the membrane forms, flashing, and seals. The membrane forms the bulk of roofing on flat roofs. In modified bitumen’s case, this is where bitumen and reinforcing materials are layered. The more layers there are, the longer the life span can be. Flashing generally refers to anything that creates a seal around interruptions in the body of the membrane. These include pipes, vents, and roof edges. Seals refer to any sealed overlap (i.e. joint) between two waterproof materials. It could be any combination of membrane and flashing. Depending on the polymer blend, cold adhesives, hot-welding, or self-adhesion can be useful in creating seals. Roof failures are known to occur in seals and flashing, so the installation calls for special care to ensure that these parts are sealed continuously. Then the aluminum coating is installed to ensure that everything is up to the code and regulations set by the city of Chicago.
Please call Roofing by Hernandez today for your free consultation on a modified bitumen roofing system and/ or aluminum coating.