A+ Roofing and Home Remodeling

• Modified

Advantages

• Granular surface - helps protect this Asphalt/SBS Rubber based product against water

• Modified can last a long time when installed on a low slope roof with a minimum 1/12 pitch.

• Smooth Modified can be coated with a white elastometric or other protective coating every 3 to 7 years to extend its life will beyond most 10-year warranties.

• Both the GTA & STA have a polyester mat for increased water resistance.

Disadvantages

• Most warranties are 10 to 12-year material only.

• Degrades very quickly on flat roofs with standing water (usually within 5 years.

• Left uncoated modified will degrade with exposure to the sun, ice & water.

• Most modified is applied with an open flame or torch (GTA & STA) for the best adhesion, creating a risk if not installed properly.

• TPO (Thermoplastic Polyolefin)

Advantages

• Seams are heat welded to avoid adhesive failures

• White Surface reflects 85% of harmful U.V. rays to extend the lifespan of white TPO

• TPO is a fully adhered roof membrane secured by screwing through the underlying wood decking, making it more secure than modified roofing. Adhesive can be used to assist bonding, especially at flashings.

Disadvantages

• TPO Surface bonding to the reinforced mesh has been a manufacturing problem with many manufacturers. The most reliable product that has proven stability is manufactured by Carlisle.

• TPO is vulnerable to impact from hail.

• Reinforcement in TPO is a lot less than in reinforced PVC woven reinforced membrane.