Roofing Felt Paper Behind Siding

I need to do some repairs under my siding from a window leak.

Roofing felt paper behind siding.

Felt paper also commonly referred to as tar paper is an underlayment material applied to bare walls before siding is installed. Many builders use standard 15 pound roofing felt. Felt or building paper must be applied to walls properly to be effective. I ve opened up houses built less than 5 years previous and the tyvek was shreaded like old newspaper.

They were built in the 1950s and 60s the felt was in perfect condition. The short answer is that felt paper is fine as a weather resistant barrier behind vinyl siding and will not cause a problem if the siding is installed correctly. Tar paper does not offer this. I ll stick with tried and true felt paper.

Siding applied directly over tar paper creates a sandwich effect and can trap water between the siding material and the tar paper. The siding was improperly installed and was removed in early november of 2018. In fact many builders disagree on the effectiveness of house wraps altogether and while some builders will only install 15 pound asphalt saturated felt paper underneath exterior siding others swear by plastic fabric house wraps such as typar or tyvek. Should any water get past the siding properly installed felt paper.

Nowadays low cost 15 felt can weight as little as 8 to 12 pounds per square 100 sq. Fiber cement siding covered the felt paper. If you want vertical drainage with tar paper you have to add treated lumber strips on top of the tar paper. Our house was built about seven years ago.

Felt labeled astm 15 meets specific standards and is the norm in many areas. Basically all model codes agree on the need for a weather resistant barrier paper usually specified as 15 felt or grade d kraft paper behind stucco brick stone and other porous veneers. But because the vinyl siding covers the felt paper it is shielded from the sun and never gets hotter than the temperature of the siding from solar gain. The homeowners immediately noticed a petroleum odor when for six years there was never a problem.

The paper requirement is typically omitted for other types of siding when they re installed over rated structural sheathing. Asphalt felt tar paper the standard requirement is type 1 felt meeting astm d 226 standards. I have seen literally hundreds of houses stripped of asbestos siding that had 15 felt under it. A paul fisette director of building materials and.

For example an ice dam or roof leak may allow liquid water to get behind the felt or housewrap. The standard weather barrier used traditionally under wood vinyl and other siding materials is 15 pound felt. They also promote quick drying allowing air to get behind any siding. Install pieces in the correct order and make cuts carefully so any moisture can travel downward at all points without slipping under the wrap.