Breathers

Happy

I attended a roofer show in Europe recently and found breathable synthetic underlays to be the rage. After doing some minor research, I saw there are some products in the US & Canada as well now. Do any of you have experience with these products? When would you ever need a breathable roofing underlay?

River Rat Dad

allegedly for interior moisture to escape without condensation forming. I am sceptical about how efficent those things really are.

Happy

I am skeptical to, but they are actually code in Europe, especially for cathedral ceiling roofs where the insulation comes into direct contact with the sheathing.

From reading some of the past chats on synthetic underlays I noticed that there was some concern communicated regarding the permeability of synthetics vs bitumin. Roofshield was suggested, but I still don't understand what the concern is/benefit? Has anyone experienced any issues with trapped moisture between the sheathing and the underside of the underlay?

catalfanoc

Isn't that why they make baffles