Do You Need A Vapor Barrier Under Lp Siding

There is no logical reason not to have house wrap under vinyl siding and many authorities strongly agree that it should be viewed as mandatory even if your local building codes don t necessarily require it.

Do you need a vapor barrier under lp siding. A shed without heat and air conditioning does not need to have a moisture barrier as it will cause condensation and mold growth. A wrb is to varying extents a vapor retarder but not a vapor barrier. If you plan to build your shed on a concrete floor a plastic barrier under the slab will prevent moisture from entering through the concrete. They will breath and excessive moisture should escape through the exterior siding.

If you live in climates zone 5 6 7 or 8 most building codes require a vapor retarder a less stringent barrier than a vapor barrier on the interior side of the wall assembly. Third a true vapor barrier is installed on the heated side of the wall studs not under or over the exterior sheathing. Whether or not you need a vapor retarder hinges on three main factors. However if you re interested a residing project offers the perfect time to examine your home s weather barrier and exterior insulation and improve it if need be.

Wrbs including tyvek are vapor permeable. Do i need a vapor barrier in my shed. The installation instructions explain that smartside is installed with nails or screws not adhesive. Why do homes need house wrap.

But this wrb is not a vapor barrier. What s more you re in an area of the country where you probably need to put the vapor barrier on the outside of your addition. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. We also provide a master index to this topic or you can try the page top or bottom search box as a quick way to find information you need.

Sources of leaks into a vinyl sided building. A wrb is more of a water and moisture resisting barrier than a vapor resisting barrier and it also serves when installed correctly as a drainage plane for water and moisture get behind the siding as will happen. You don t want a vapor barrier in this location. In the end the decision to install house wrap under your siding is a personal one that you should make after discussing it with your contractor.

A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Vapor barriers vinyl siding. Vinyl siding is one of if not the most popular exterior cladding for residential homes. Housewrap vapor barrier requirements for vinyl siding article contents.

The wall cavities and insulation must have a a way to breath. According to the installation instructions for smartside siding lp smartside 76 series lap siding may be attached directly to framing members spaced up to a maximum of 24 in 600 mm on center so you don t need any sheathing under the siding.