How To Install Vapor Barrier Between Floor Joists

Mike in victoria writes i m putting a new subfloor on a pier and beam foundation.

How to install vapor barrier between floor joists. One common mistake people make when insulating a floor is to install faced batts between the floor joists with the kraft paper facing. On 2018 08 31 by mod many cuts and staples in poly risk a rather leaky moisture barrier. After insulating between the floor joists with the vapor barrier up i want to cover the bottom of the floor joists with house wrap. Start at one edge of the crawlspace and install the insulation between the floor joists.

5 the orientation of the vapor barrier depends on the home s location and climate. Do i need a vapor barrier between the floor joist and the plywood for a new subfloor on a pier and beam foundation. If using faced insulation keep the paper vapor retarder facing up and against the subfloor. Because excessive dampness in a crawlspace or basement can condense you can install a vapor barrier to protect floor framing from becoming damp and covered with fungus efflorescence and rot.

Do i need a vapor barrier between the floor joist and the plywood. Make sure each run contacts the insulation you installed at the header band joists. Install the insulation between the joists with the vapor barrier. The other vapor barrier is created with your floor insulation.

It is important to secure insulation and cover it with a vapor barrier in order to prevent moisture and the mold that often follows close behind. The ground floor could be river rock pea gravel dirt floor sand etc. The house was built back in 1926. Of course you can follow the procedure you want to.

A 6 mil polyethylene vapor barrier is placed over any ground floor. If your house is elevated and the crawlspace is under that elevation so as to be exposed to the outdoor air then you are fine. Vapor barrier on ground floor of crawlspace the most common and correct method for installing a vapor barrier in a crawlspace. A better installation if you are installing a basement ceiling poly vapor barrier during new construction is to place the poly either directly atop the first floor joists dangerously slippery during installation or to place the poly barrier atop the subfloor and underneath the next layer of flooring underlayment as the first floor is being built.

If the crawl space is ventilated which is ideal because it aids in the elimination of moisture then fiberglass insulation can be easily installed under the subfloor between the floor joists. The insulation should fit snugly against the subfloor and between the joists. A vapor barrier consists of one or more layers of sheet plastic 6 mil visqueen on top of the soil in the crawlspace or basement.