Should you put plastic under concrete driveway?

The American Concrete Institute (ACI) recommends a minimum of 10-mil polyethylene or thicker for vapor retarders under concrete. Their Guide to Concrete Floor and Slab Construction ACI 302.1R-15 identifies that thicker poly provides a better barrier and is also more puncture resistant.

What do you put under a concrete driveway?

The best sub-base for a concrete slab is gravel. The soil has to be prepped first before the gravel can be laid down; pouring concrete directly onto rock is not considered a best practice. You can use different kinds of gravel for the subbase as long as it is clean and uniform in shape and size.

Do you need a vapor barrier for a driveway?

Is Having a Vapor Barrier Necessary by Code? All concrete slabs used in heated structures must have a vapor barrier installed. A minimum of at least 6-mil polyethylene vapor retarder must be installed between the concrete and prepped ground, according to the 2018 IRC.

What kind of plastic goes 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.

Can concrete be poured over plastic?

You can build a framework around the concrete slab with lumber, PVC pipes, or rebar to hold the plastic sheeting. Another method to prevent discoloration is to place dry straw directly onto the concrete, then put the plastic on top of it. Wet the concrete, then place the plastic sheeting over it.

Why do you need a Vapour Barrier Under Concrete Slabs - The Structural Why Files aswers the question

Do you need 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.

How do you install a vapor barrier on concrete?

How do you prepare the ground for a concrete driveway?

Ensure there is enough room by the stakes to set the forms on. Use shovels and rakes to make sure there are no weeds, large rocks and stones left within the area. Then add the forms, fill in the area with at least 4 inches of fill sand, stone or gravel and wire-mesh reinforcement as a solid base for the concrete.

What is the best base for a driveway?

Can I pour concrete directly on dirt?

Long story short, yes you can pour concrete over dirt.

Can I use plastic as a moisture barrier?

You can use plastic if you put polyethylene between your drywall and the wall studs. This way, you should get a tighter wall without trapping moisture inside the exterior walls. If you are framing out a below-grade basement, however, do not use plastic as a vapor barrier.

Is plastic sheeting a good vapor barrier?

Plastic, specifically 6-mil polyethylene plastic, is the most commonly used vapor barrier. Plastic has a very low permeability rating, which means water, in its gaseous or liquid state, does not travel through it.

What do you put under a concrete slab?

Because concrete is a very porous material, it will absorb any moisture that it contacts. This can cause pooling. Without crushed stone, pooling water will settle under it and erode your slab. Adding a layer of crushed stone will add proper drainage, as well as create a barrier between your slab and the ground.

Do you need a membrane under concrete?

These days, damp proof membranes are required in the construction of all new buildings to prevent rising damp. These strong and highly durable Polyethylene 1200 Gauge DPMs are sandwiched between the hard core and concrete slab to form an impermeable layer.

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 vapor barrier be under a concrete slab?

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 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.

Can moisture come up through concrete?

Humidity—warm and humid air condenses into surface moisture when it comes into contact with the cool surface of your concrete floor or slab. Faulty/Missing Vapor Barrier—moisture from the ground can seep up and through the concrete.

Where should I place my vapor barrier?

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 vapor barrier?

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.

Is Poly a good 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.

Do you need gravel under concrete?

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.