Do You Need Underlay for Torch on Felt?

While roofing felt isn't the cheapest, it's one of the most effective systems. ... The torch-on felt solution relies on a three-layer system, which will require two levels of underlay underneath the cap sheet.

Do you need underlay for felt?

You can increase the lifespan of new shed felt by using a method that is also used to protect the roofs of other buildings and structures when they have a pitch of less than 20 degrees. To use this method, you will need to use an underlay, which will need to be put in place before you install the shed felt.

What do I need for torch on felt?

Traditionally, the three layers used in this process are a vapour control sheet, reinforced felt and a cap sheet with mineral finish. Using three layers of felt is required by building regulations for habitable areas of a home. For sheds and garages, only two layers may be needed.