Do you need a vapor barrier with unfaced insulation?

In most climates, it needs a vapor barrier. Some builders rely on batts with attached kraft-paper facing to do that job, but Tom recommends unfaced batts, covered in plastic with all the seams taped shut.

What do you cover unfaced insulation with?

Cover the newly installed insulation with a layer of plastic sheeting or other vapor barrier only if there isn't already a vapor barrier in place. If the insulation is installed over existing insulation, either faced or with a barrier over top, adding another vapor barrier will lead to structural problems.

Is it OK to use unfaced insulation on exterior walls?

Unfaced insulation is non-combustible.

However, it's common for a layer of faced insulation to be used in the exterior walls and attic ceilings to prevent water from entering the home, while unfaced insulation can be added to improve the heat retention ability and reduce the risk of fire.

When should you use unfaced insulation?

Unfaced insulation is great for new construction, remodels, walls, floors, ceilings, basements, attics and crawlspaces. It's best used for interior wall applications that do not face the outside and also in rooms that don't need moisture control, like living rooms, dining rooms and studies.

Do you need plastic over faced insulation?

In most climates, it needs a vapor barrier. Some builders rely on batts with attached kraft-paper facing to do that job, but Tom recommends unfaced batts, covered in plastic with all the seams taped shut.

Vapor Barriers: Need one or not?

Do you need to staple unfaced insulation?

Unfaced insulation goes up more quickly than insulation with paper or plastic facing. Flaps on faced insulation must be stapled between rafters to hold it in place. However, the lack of facing means that you must add a moisture barrier over the insulation.

Is paper faced insulation considered a vapor barrier?

There are two basic types of vapor barriers used with exterior wall insulation. The most common is paper-faced insulation. This type of insulation has a Kraft paper face with two flanges.

Is vapor barrier necessary?

A vapour barrier is an important component in building construction. Its purpose is to help prevent water vapour from reaching building walls, ceilings, attics, crawlspaces or roofs, where it can condense and cause building materials to rot or grow mould.

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.

How do I use unfaced insulation?

Unfaced insulation—the type without paper—is what you would use if you are adding insulation to your attic or to place between floors when living space is above and below. Unfaced is also your best choice for adding soundproofing to interior walls.

Should insulation paper face in or out?

Regardless of whether fiberglass insulation is installed in a wall, attic, or crawlspace; the paper facing should always face toward the inside of the home. That's because the paper contains a layer of asphalt adhesive which prevents water vapor from passing through it.

Is it OK to use unfaced insulation in attic?

When installing between the roof rafters of finished attic spaces, you can use either faced or unfaced batting. When using insulation that has paper or plastic batting, that moisture barrier should face outward toward the attic space.

Do vapor barriers cause mold?

One of the more common problems with crawl spaces that do not have a crawl space vapor barrier system is that they create high moisture levels, which may result in mold growth – as dampness creates the ideal environment for mold growth.

Is it OK to put plastic over insulation in attic?

Plastic isn't recommended in this situation because it would create a second vapor barrier that can trap moisture and result in condensation and mold. Craft paper would have the same problem, this is what is most likely on the other side of the insulation for the vapor barrier you want.

Where should vapor barrier be placed?

Vapor barriers are usually best installed on the side of the wall that experiences the hotter temperature and moister conditions: the inner surface in colder climates and the outer surface in hot, humid climates. In existing spaces, oil-based paints or vapor-barrier latex paints offer an effective moisture barrier.

Do I need a vapor barrier behind drywall?

The presence of an interior vapor barrier makes drying out the cavity harder to do, though. Without poly beneath the drywall, water vapor hits the drywall and diffuses through to the drier (in summer) indoor air.

What side does vapor barrier go on insulation?

In order to prevent condensation from forming, a vapor barrier should be placed on the warm side of your insulation to stop warm, moist air from condensing on a cold surface inside your wall.

What is the purpose of paper backing on insulation?

The Purpose of Insulation Facing

The paper creates a vapor barrier that helps keep the water vapor in the warm, moist, heated indoor air from migrating outward into the wall or other structure. For this reason, faced insulation is typically installed on the "warm in winter" side of the wall.

Can you put unfaced insulation over faced insulation?

No, faced insulation should not be added over existing insulation since the vapor retarder on top of or between layers of insulation can trap moisture. Let Accurate Insulation handle your home insulation project from start to finish.

Should I use 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.

Should insulation seams be taped?

Yes, you tape any insulation's lateral seams, especially any fluffy stuff... aluminum HVAC tape lasts the longest. The fluffy stuff really only works best in dead air space. Which also means the un-faced side (where you don't tape anything).

Should faced insulation be stapled?

Use enough staples to hold the insulation firmly in place (about every 8") and avoid gaps and “fishmouths” between the flanges and framing.