Does ceiling insulation need a vapor barrier?

Vapor Blockers Vapor barriers—sheets of plastic or kraft paper—keep water vapor out of the wall cavity, so the insulation stays dry. Not every type of insulation needs a vapor barrier. But if it does, the barrier should face inside in northern, heating climates, and outside in humid southern climates.

Should you put plastic over ceiling insulation?

It depends on your local climate. For climates that are higher humidity inside than outside in summer (a dry climate) plastic on the interior is OK. For climates that are higher humidity outside during the summer (a humid climate) plastic on the interior could be a serious mistake.

Do you install vapor barrier ceiling?

It is essential to have a vapor barrier installed with your ceiling insulation. It’s not uncommon for moisture and dew to form on a ceiling because of the temperature differences; moisture can cause mold and rot if left unchecked.

Do you vapour barrier ceiling or walls first?

To start installing poly it does not really matter if you do the walls or ceiling first but I prefer to do the walls in a room first. So to do the walls start by deciding how big of a piece you can handle and cut if from the roll. I would start with about a 8 foot piece until you do one to make it easier.

Should ceiling insulation be faced?

Facing creates a moisture barrier through which moisture does not travel. Whether it’s made of paper or plastic, it always faces whichever space is typically warmest in winter.

Should I put a vapor barrier on my basement ceiling?

If the basement is finished and has no moisture issues, the vapor barrier is not needed. If it has moisture issues, the vapor barrier is probably a problem.

Should you put plastic between insulation and drywall?

Without poly beneath the drywall, water vapor hits the drywall and diffuses through to the drier (in summer) indoor air. By installing a sheet of poly there, you cut off that drying mechanism and water that finds its way into walls can stay there longer and do more damage.

Does vapor barrier go before or after insulation?

After the insulation is in place you will want to add a vapor retarder, sometimes called a vapor barrier, if you need one. Not every wall does. A vapor retarder is a material used to prevent water vapor from diffusing into the wall, ceiling or floor during the cold winter.

Do I need faced or unfaced insulation in my attic?

Faced Insulation: If the attic doesn’t have any existing insulation, use faced insulation with the paper facing toward the heated living space. Unfaced Insulation: When adding more insulation to an attic that already has insulation, use unfaced insulation.

Where does the vapor barrier go in a basement ceiling?

You want the vapor barrier on the oppsite side – the upper side of a basement ceiling. You can achieve that if you have, for example, sheet vinyl or something else that seals over the floor above. You are going to find that an inch of spray foam out of little cans will be quite costly.