Felt Paper Under Siding

[Temp97]

JB , it's vinyl. I would have said that felt paper is just fine and would have advised it to any one, but as soon as I start a project all the head scratchers come out and ask the age old question "Watcha ya doing that for"!

Thanks all

 

[jinman]

When I built my house with cedar siding, the plans called for felt under the siding and I didn't think to spec Tyvek until it was too late because the felt was already up. On the south facing wall with a large flat exposure and no shade, the sun just beat the heck out of the cedar siding. It dried, bowed, split, and popped out a few nails from all the expansion/contraction. Last year I replaced the siding with Hardiplank over foil faced foam and Tyvek. It turns out that during removal we found the cedar was in much better shape than I thought and very strong despite being dried by the sun and the heat from the tar paper. Even so, with the new siding and insulation, the inside of my house is a different place. What went from a very warm bedroom has now turned into one of the coolest rooms in the house and it's on the third level of my multi-level house. My suggestion to anyone putting on vinyl siding is to consider adding another outer insulation layer under the siding if you live anywhere in the sunbelt states.

 

[Danno1]

My suggestion to anyone putting on vinyl siding is to consider adding another outer insulation layer under the siding if you live anywhere in the sunbelt states.

Or the northern states!


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[JJP]

I can never figure out how with a thousand holes in the tyvek that it all of a sudden becomes an air barrier.!! I always use a 30# felt and have not had any problems. I think there is just too much hype. Plus you can detail windows better with felt and with metal flashing. Thanks.

 

[BeezFun]

A trade journal called the Journal of Light Home Construction published the results of testing that was done at some university about 10 years ago, comparing all the house wraps including felt paper. The felt paper was about as good as the newer house wraps in all categories and really excelled in one I thought was the most important. When felt paper gets saturated it still displays good water barrier characteristics. The house wraps on the other hand passed water easily once they got saturated. Since the primary purpose of the wrap is to be a water barrier, that seemed like a significant point. Also the cost difference is large between felt paper and the house wraps. The other thing I noticed on the job all the time was that the quality of the installation was far more important than what material was used. I saw house wrap lapped the wrong way, no tape on the joints, big sheets torn off by the wind, etc. You could use christmas foil wrapping paper and have a better outcome if the installation was done properly.

 

[wesmann]

That university was probably the Building Materials and Wood Technology department at UMass, Amherst. Lot of great publications for builders and home owners at their site.

UMass Amherst: Building and Construction Technology Publications by Title

check 'em out