How thick should slab vapor barrier be?

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.

How thick should my vapor barrier be?

Vapor barriers should be at least 6 mil in thickness to effectively cover the area and create a moisture barrier. Triangle Crawl Space Solutions uses both a 6 mil material for simple vapor barrier installation and a thicker more durable 12 mil vapor barrier material depending on the budget and needs of the home.

Do you need vapor barrier under slab?

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.

What mil plastic should you put 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.

How do you install a vapor barrier on a concrete slab?

Why a Plastic Vapor Barrier Under Concrete Slab - Mondays with Mike

Can you use 4 mil vapor barrier?

OVERVIEW. Our 4-mil plastic sheeting is a multipurpose film perfect for a wide variety of construction or DIY projects. This medium-duty plastic sheeting is commonly used as a vapor barrier in between insulation and drywall, used as a drop cloth or a temporary cover for equipment and supplies.

Should I staple vapor barrier?

Tug and smooth the vapor barrier to ensure a completely smooth surface lacking wrinkles or gaps through which moisture and air may escape, defeating the vapor barrier's purpose. Staple through the plastic into the sole plate -- the horizontal board running under the studs – at bottom.

What do you put under a concrete slab?

You do need gravel under a concrete slab, footing, or patio. Gravel provides a solid foundation for your concrete as it can be compacted. It also improves drainage, preventing water from pooling beneath the concrete.

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.

Should I put a vapor barrier under concrete?

If you have a concrete floor that's in continuous contact with a source of moisture, you're going to have problems. This is why a vapor barrier under concrete is essential. Vapor barriers are a way to keep moisture from getting into the concrete.

Does vapor barrier go above or below slab insulation?

The industry consensus is that underslab vapor barriers should be installed if the slab will be in conditioned space, or if the slab will be covered with a moisture sensitive flooring system. The underslab barrier should be less permeable than the floor covering.

Should vapor barrier be clear or black?

Black barriers are more effective at stopping moisture evaporation, compared with the clear barrier. The black color hinders the growth of plant seeds that may reside beneath a home's crawlspace. Plants naturally send moisture into the air, creating more moisture.

Can I use 6 mil plastic for vapor barrier?

Reinforced polyethylene plastic sheeting (poly) comes in a variety of thicknesses and strengths. A 6 mil thick poly is commonly used as a vapor barrier and offers short-term savings to the homeowner.

What does 6 mil vapor barrier mean?

This number refers to the thickness of the plastic. To be more precise, 6 mil means 6 millimeters or 0.006 inches thick. The thickness of the product adds to the life expectancy of the vapor barrier.

Can I install vapor barrier myself?

Provided you're not claustrophobic, installing a vapor barrier is a project most homeowners can DIY. You will need to calculate the square footage of your crawl space, so you can buy the appropriate amount of liner.

Which side does vapor barrier go on?

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.

Is 4 mil thicker than 6ml?

Generally speaking, higher MIL designation equates to a thicker and strong plastic sheathing. The most common plastic sheeting sizes found in local hardware stores are 2, 3, 4 and 6 MIL poly sheets.

Can I use plastic sheeting as a vapor barrier?

In simple terms, a vapor barrier is a material that won't allow moisture to pass through it, such as plastic sheeting. A very simple experiment to show how a vapor barrier works is to lay a plastic garbage bag down on some damp soil.

Which is thicker 10 mil or 16 mil?

The bigger the number the thicker the plastic. Plastic sheeting comes in ranges from 1 mil to 100 mils! A "mil" A mil is a measurement that equals one-thousandth of an inch, or 0.001 inch. Most human hair is one-thousandth of inch, or 0.001 inch.

Where does the vapor barrier go under a concrete slab?

From a moisture-protection standpoint, it is my strong belief – reinforced by decades of ACI study and expert opinions – that the under-slab vapor barrier should be located directly below the slab, without the use of a layer of granular fill (sometimes sand) sandwiched between the slab and vapor barrier, often referred ...

How thick should a foundation slab be?

A slab foundation is made of concrete that is typically 4" to 6" thick in the center. The concrete slab is often placed on a layer of sand for drainage or to act as a cushion. Houses built on a slab lack crawlspaces, and there is no space under the floor.

How thick should concrete floor insulation be?

A 50mm thick layer of proprietary floor slab insulation (e.g. 50mm Kingspan, Celotex or similar) is usually enough to reach and maintain the target U value but this should be checked with an architect first. Insulation sheets should be laid tightly together with the joints staggered to avoid movement.