Do we need housewrap?
user-6724719
| Posted in GBA Pro Help on
Building a new home in Hanover NH. Advantech sheathing will be taped. Then 2 1/2 inches of XPS will then be applied and taped. Then firing strips, then Hardy siding.
Initial plan was to place house wrap on outside of of XPS. Our builder says that perhaps house wrap is not necessary, given the tape on sheathing then again on XPS, but he is willing to add it if we prefer.
Is there any advantage to house wrap with this construction method?
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Replies
Dupont (a competitor) got good videos of the weakness of no house wrap, see
http://www.dupont.com/products-and-services/construction-materials/building-envelope-systems/videos/moisture-in-coated-sheathing.html
http://www.dupont.com/products-and-services/construction-materials/building-envelope-systems/videos/zip-reverse-shingling-vs-tyvek.html
http://www.dupont.com/products-and-services/construction-materials/building-envelope-systems/videos/overdriven-fasteners.html
Frank, you should read this from Martin: https://www.greenbuildingadvisor.com/blogs/dept/musings/using-rigid-foam-water-resistive-barrier.
Frank,
Building codes require (and building scientists recommend) that every house have a water-resistive barrier (WRB). The WRB is not optional.
You can use rigid foam as a WRB if you want, but there are caveats and limitations. Integrating the window flashing with the WRB because a little trickier when you use rigid foam than it would if you used housewrap. Here again is the link to my article on the topic: Using Rigid Foam As a Water-Resistive Barrier.