Can you put a vapor barrier over concrete?
Subfloor Material Therefore, because concrete is porous, it’s a good idea to install a vapor barrier over your concrete subfloor before installing your flooring. This way you can stop the vapor drive of water upward to your floors, protecting them from any damage (source).
Is vapor barrier necessary for concrete?
Exterior concrete slabs or those in unheated structures don’t require a vapor retarding barrier. However, if the surface will be sealed with an impermeable membrane or product, there should be a vapor barrier under the pad.
How thick should a vapor barrier be under a concrete slab?
10 mils
A vapor retarder that is torn or punctured provides a pathway for moisture to enter the slab from below. 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.
What can I use for vapor barrier under concrete?
The most commonly used vapor barrier under concrete slabs is polyethylene (poly) plastic sheeting with a thickness of 10 mil or 15 mil. All Americover Vapor Barriers are composed of virgin polyolefin resins and offered in 10 mil, 15 mil, and 20 mil.
Does sealing concrete stop moisture?
Basements and garages – the typical rooms with concrete floors – also suffer from poor air circulation, giving the moisture nowhere to go once it seeps through the floor. Sealing the concrete can help eliminate the dampness on your floor.
Do you need black plastic under concrete?
Vapour barriers are the black (or orange) plastic that builders put under residential house slabs. They do this for two main reasons: to prevent moisture from the soil permeating up through a slab and into a house (also known as rising damp); and.
What is the difference between a vapor barrier and a moisture barrier?
Moisture barriers function to help in preventing water from entering inside of the wall cavity. On the other hand, vapor barriers basically prevent water vapor from the interior of the house to filter through the wall and condense on the warm side of the insulation.
What should I put between wood and concrete?
Anyplace where wood meets the ground or concrete, the lumber must be pressure treated. For additional moisture protection, a gasket or strip of closed-cell foam can be installed between the concrete foundation and the sill plate.
Where does the vapor barrier go in slab?
- Most exterior slabs do not need a vapor barrier.
- In general, place the concrete slab directly on top of the vapor barrier, with the subbase below.
- The vapor barrier can be placed under the subbase, if the building is closed in when the dry subbase material is placed.
Where should a vapor barrier be installed?
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.