Torch Down Roofing Underlayment

Modified bitumen roofing may have a granular surface as shown here or it may be smooth.

Torch down roofing underlayment. What type of underlayment should i use. Care must be taken to apply the overlay board correctly to prevent ponding which is when the roof is not level. Torch down roofing is a type of roofing material that has been designed for low angle or flat roofs. While it can last up to 20 years installing torch down roofing can be a dangerous process and as such tends to cost more than traditional roofing materials.

The roofing professional will lay down an overlay board or cover board next to support the torch down roofing membrane. Use flashings approved by your building department. These steps show a torch down method which looks a bit scary but actually is not too difficult. If you install the smooth product cover it with aluminum coating.

The sealed sheet also serves as an effective flame retarder for the application of torch applied modified bitumen membranes. I m going to be re roofing an addition on our house that is low slop and would like to use torchdown roofing. This membrane contains a core of nonwoven polyester mat that resists splits and tears. The mat is coated with durable app modified bitumen and is designed for torch down application by professional roofing.

This underlayment helps prevent the roof from developing condensation or moisture issues. Tri ply 75 base sheet is a premium roofing base sheet constructed with a fiberglass mat reinforcing that is coated on both sides to ensure a closed sheet design to prevent asphalt bleed through. I originally was going to use ice and water shield but don t think i want to put torch down on top of that. It is best to use 75 glass base underlayment.

Renting a large propane torch is. Priming the underlayment is not needed. As long as it is installed correctly bitumen prevents moisture build up without needing constant maintenance. Gaf tri ply app smooth is a strong resilient membrane that is suitable for new or reroofing projects as well as for use as flashing.

Torch down roofing consists of modified bitumen which is similar to asphalt.