BUR (Built Up Roof) & Modified Bitumen Roofs:
The concept with these types of roofs is that they are “built up” with multiple layers of roofing membrane usually with hot asphalt or adhesives. Since they have multiple layers fused together with a water-resistant material, they are very resilient and provide excellent waterproofing properties. The top layer usually has ceramic granules embedded into membrane that protects it from the elements which is a light gray color or could be white. These systems may include insulation for thermal and/or drainage properties.
The difference between a BUR & Modified Bitumen membranes is that the latter is reinforced with a SBS polymer which makes it flexible, more tear resistant and much more resilient.
TPO roofs are a durable long-term solution with some of the best warranties available from manufacturers. TPO stands for thermoplastic polyolefin, a blend of polypropylene and ethylene-propylene rubber reinforced with a polyester backing. All seams are heat welded together to form one monolithic roof covering with superior strength. Since the roofing system is all heat welded,
the manufacturers will not void their warranty under ponding water conditions unlike all other types of systems. TPO is white on top which makes it energy efficient for the life of the system. TPO resists corrosion and break down upon contact with numerous materials. It also has excellent puncture resistance and tear strength. It also does not promote mildew or algae growth and doesn’t require pressure washing.
Liquid Applied Coating with Reinforced Fabric
This type of roofing system can be applied as a new roof or over an existing roof. The concept is to install a monolithic coat of a polyester fabric adhered to the deck with an elastomeric finish coat which is usually white. Solvent based materials are used for ponding water conditions and latex based for low sloped roofs.
Different combinations of this system may be used to renew or maintain roofs and waterproof decks and walls.
Spray Foam with Coating (SPF)
Pray polyurethane foam (SPF) roofing consists of an application of foam covered with an elastomeric coating to protect the foam from ultraviolet rays. It provides insulation, is water resistant and has excellent adhesion. It must, however, be protected by an elastomeric coating to prevent ultraviolet surface degradation, enhance the aesthetics of the system, increase the impact and abrasion resistance of the foam and achieving fire code requirements. This system is only as good as the coating which has to be regularly maintained and will blister over a concrete deck. The larger blisters need to be repaired as they will rupture with foot traffic.
Coal Tar Pitch
The coal tar pitch system is a built up roof that is manufactured on site with layers of felts adhered to the roof using hot-applied coal tar pitch. It is the coal tar that protects the roof from the elements, while the felts act as reinforcement. Coal tar’s molecular structure provides the benefit of actually healing itself with natural degradation. Specifically, any cracks that might be formed by impact or rapid drops in temperature, reseal when surface temperatures rise and the coal tar softens, it’s always in a fluid state. These self-healing properties provide a long-term roofing solution that will require less maintenance than most roofing systems. Unfortunately, coal tar has been proven to be a carcinogen and is very harmful for the installers. Most manufacturers have stopped producing it. Some contractors still install it, but it could be a future mitigation nightmare for owners like asbestos is today.
Standard or dark roofs can reach temperatures of 150°F or more in the summer sun. A cool roof under the same conditions could stay more than 50°F cooler.
A cool roof can benefit a building and its occupants by: Reducing energy bills by decreasing air conditioning needs. Improving indoor comfort for spaces that are not air conditioned Decreasing roof temperature, which may extend roof service life.
Improving indoor comfort for spaces that are not air conditioned Decreasing roof temperature, which may extend roof service life.
Reducing power plant emissions, including carbon dioxide, sulfur dioxide, nitrous oxides, and mercury, by reducing cooling energy use in buildings.