Roofing felt under wood siding?
deanbowman
| Posted in General Questions on
Rather than using the newer synthetic building wraps, I would like to use a 30lb asphalt building paper, taping the plywood seams prior to minimize air leakage. The siding I’m using is locally harvested fir 1x8s, heat treated the traditional Japanese way (Yakisugi, aka Shou Sugi Ban). That siding will then be installed over 3/8″ thick vertical furring strips for an air gap.
No one in my area sells a “building paper” or tar paper though. It is all listed as “roofing felt”. Is it the same? If not, is it suitable enough for what I want to do?
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Replies
deanbowman,
Nothing wrong with building paper as long as it gets installed close to when the siding is going on. Left exposed it tends to either get torn, or wrinkle which means it can bridge or block the rain-screen cavity.
Felt and paper are synonymous.
As Malcolm says, same thing. There is some more info about different grades here:
https://www.greenbuildingadvisor.com/question/standard-30-asphalt-felt-vs-astm-30-asphalt-felt-astm-d-266
I've used felt for small structures and works pretty well but it doesn't holdup to abuse as much as modern house wraps.
P.S. If you want the char to last it has to be pretty deep. I've tried the mild char where it looks like a very dark wood stain, lasted about 2 years. You need to really burn the wood (alligator skin finish) for it to last.
Akos,
And put a finish over it. Left to itself even deep char goes orange pretty quickly.
https://www.greenbuildingadvisor.com/article/urban-rustic-charred-cedar-siding
Thanks for the info and links, Malcolm and Akos.
Re charring wood: Though I have not done siding before, I have played around with it on sculptures...quite a bit. One, which is of a human figure, I set as a post in my yard close to 20 years ago. Despite being made from Aspen which rots about as quickly as any wood I have seen, the sculpture is still standing. For comparison, I only got 2-3 years out of Aspen posts that were not burned. They simply rotted off just below the surface.
At any rate, I plan to let the boards burn for a while. Also, the areas in which I will use this siding are protected with 8' porches and overhangs varying from 3.5' to 6'. So, there will be minimal moisture that will reach it.