Overlap any seams and tape them.
Putting up a moisture barrier roof.
A roof design that includes an adhered roof membrane with multiple layers of insulation with board joints offset and staggered over a vapor retarder air barrier helps lower the risk that air and the moisture it carries will infiltrate the roof system.
Cover the dirt crawlspace with a plastic moisture polyethylene vapor barrier.
And bring the plastic about 6 in.
Per foot is usually the best thing you can do to reduce crawlspace moisture.
Up the wall and fasten it there.
If you are not sure if you need insulation in your walls follow along with this flow chart.
Sloping the soil away from your home at about 1 2 in.
After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.
Make sure to adequately ventilate the attic area above the insulation.
Not every wall does.
Your first job after the studs are in place is to fill those walls with insulation.
In very cold climates the use of polyethylene plastic vapor barriers between insulation and interior wallboard may be beneficial provided all air gaps into any wall and ceiling cavities are also blocked.