Concrete Floor Vapor Barrier Insulation

So this is clearly an ineffective solution.

Concrete floor vapor barrier insulation.

Overlap the seams about 6 to 8 inches and seal the seams with waterproof construction tape. A vapor barrier is not the same as an underlayment. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. Vapor barriers are a way to keep moisture from getting into the concrete.

Not every wall does. When the mold grows it will spread to everything around it studs drywall etc. This is why a vapor barrier under concrete is essential. Puncture studies of 6 8 10 and 20 mil vapor retarder materials have shown that 10 mils is the minimum thickness that should be considered and thicker material may be necessary over.

If you have a concrete floor that s in continuous contact with a source of moisture you re going to have problems. For a vapor barrier below a concrete floor slab most choose 6 to 10 mil polyethylene. Below grade walls and floor slabs transmit ground moisture through concrete walls or slabs. Reflectix and similar reflective radiant barrier products provide almost no insulation under or on top of a concrete slag just r 1 for reflectix.

The barrier s unique core material is an expanded polystyrene eps with a jobsite tough heavy duty poly film. The best option under a concrete slab is foamular 250 which delivers r 5 per inch of thickness along with 25 psi of compressive strength. Lay vapor barrier. Insulating concrete garage floors begins with covering the entire floor with 6 mil polyethylene which will serve as a vapor barrier.

The american concrete institute s guide for concrete floor and slab construction recommends that the thickness of the vapor retarder be at least 10 mils. This barrier is meant to keep moisture from getting to the insulation in the walls and ceilings and it is required by building codes when insulating most houses. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Because extruded polystyrene insulating board will absorb little moisture the vapor barrier can be placed above or below the slab insulation.

In any case the vapor barrier must point to the warm side. A vapor barrier against the concrete surface is generally recommended before wood framing or flooring materials are installed. Very hot and humid climates may benefit from an exterior vapor barrier that keeps outside humidity from penetrating into walls.