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If anyone wants a free one-square sample roll of a new synthetic underlayment (complete with ICC-ES ESR #), please e-mail me for details.
It is a woven polypropylene fabric with a patented rubber-modified top surface.
We currently have a Hitachi Plasti-Tacker, and I'm trying out a Grip-Rite and the new Bostitch cap nailer. The Hitachi is a nice gun, as is the Bostitch.
Contact us for all you mailbox post installation needs!
Synthetic underlayments are inferior to felt paper products due to their low permeability. Even though shingles have a low permeability felt paper creates a buffer zone between the wood decking and shingles ensuring the wood deck remains dry. This is very useful in ensuring new wet lumber installed as roof decking can release the excess moisture. Having two low permeabile products on top of one another is never a good idea and is not a practice followed by elite contractors. Felt paper also absorbs liquid water and wickers liquid water away from the wood deck helping to keep the wood deck dry due to liquid water penetration. Paper will hold the excess water allowing it to evaporate through the roof ventilation. Synthetic underlayments do not absorb any water and do not wicker moisture away from wood decking.
Wrap a wet piece of lumber[osb for quicker results] completely with felt and another with synthetic underlayment. Leave it for a year and unwrap and you will witness the superiority of felt paper.
I know this is an old thread but wanted to chime in.
I've used it in the past for under metal roof systems but using right now on a shingle project for the first time.
The only reason I paid the premium was for piece of mind due to higher weatherbility. Doing a large project over a hospital with on going operations so a leak over the operating room can be a major issue. 15lb felt was specd but I went ahead and bid the synthetic.
I'm using the certainteed diamond deck. It's so much nicer going forward felt paper won't even be an option on my jobs.
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