Do You Need Plastic Under Concrete Driveway

Do You Need Plastic Under Concrete Driveway
  • Author: Amanda Arnold
  • Posted On: September 10, 2022
  • Updated On: August 21, 2023

Concrete conjures up images of a beautiful, reliable, adaptable, useful, and high-quality product. The most common building material worldwide is concrete. Installing a vapor barrier beneath the concrete driveway is a crucial decision.

Concrete is porous, which allows rainfall from the ground to seep through the surface. If possible, seal any exposed concrete floors before leaving them uncovered. If the flooring is made of concrete and has an impenetrable polish, you need to install a vapor barrier or plastic.

What Is The Type Of Plastic Used In Concrete Driveway Construction?

A layer that stops or delays moisture vapor ingress is referred to as a vapor or plastic barrier. It is also known as a moisture or vapor retarder. Vapor barriers frequently consist of plastic coating. But it’s not always the greatest choice.

Concrete’s porous nature allows for groundwater to seep up through it and into any surfaces it comes into touch with, including flooring. A moist bottom could lead to the growth of mold or mildew, and ground vapor leakage could ruin concrete platforms and floors.

Water cannot pass through concrete without the help of a vapor retarder, also called a barrier. In this case, groundwater may rise through the concrete. A mil is one-thousandth of an inch. The thickness of different items is measured in mils, which is a unit of measurement.

Is Moisture In Concrete Dangerous For Driveway?

A problem with too much moisture in concrete is that it might lead to pH fluctuations that weaken adhesives. Here is what transpires. Soluble alkalies accompany moisture as it travels to a concrete slab’s surface, raising the pH there above that of flooring adhesives.

Due to the disintegration of the adhesives, you experience flooring failures like swelling or cupping. Even while it may take up to a month for concrete to fully cure, it starts to harden within an hour of pouring and completes the process in about 24 hours, giving you a firm slab that is ready for use right away.

Because of this, before pouring concrete, whatever you plan to place in or beneath it must be ready. Before pouring concrete, always seek advice from a specialist or the local building department.

Placing Plastic Under Concrete Is Essential

Vapor barriers must be built on all concrete slabs used in heated constructions. Between the concrete and prepared ground, polyethylene vapor retarders must be put at a minimum. Additionally, the barrier must have a 6-inch overlay of joints or seams that must be sealed with a suitable material.

Unless they will be heated later, unheated structures like garages and utility buildings are likewise exempt from the requirement for a moisture retarder. On the other hand, unless you eventually enclose them inside a heated structure, patios and driveways do not require a barrier.

What Are The Negative Effects Of Not Using Plastic Under Concrete Driveways?

The majority of building rules mandate the use of a vapor barrier when constructing a concrete plate or floor inside a heated building. To prevent the concrete from becoming wet, a vapor barrier is placed beneath it.

This could cause the residents of this home to experience a lot of concrete dampness. You need to install something under your concrete floor to prevent mold and mildew from growing in your house. If you don’t do this, your house can get excessively moist, which would encourage the growth of mold and mildew.

It is possible for wall and floor structures that are overlaid to become wet, expand, or degrade in touch with the base. Even though unheated driveways can be built with concrete floors alone without the need for a vapor or moisture retarder or barrier, some DIYers and contractors advise it.

If a metal object is sitting on a concrete pad, moisture that enters the structure via the flooring could cause dampness, rust, and even discolor the concrete.

How To Install Plastic Or Vapor Barrier Under Concrete?

Before laying a concrete slab, installing a vapor retarding barrier is practically the last step. Ascertain that the earth, aggregate, and sand layers have been leveled, compacted, or rolled. The final layer is laid down before the vapor membrane material is rolled out.

Even over any firm foam insulation, it ought to be the final layer before the concrete. The barrier should climb any walls and be cemented to the concrete of the foundation with the proper binders.

Bottom Line

There is disagreement about the best sort of moisture barrier to employing and where to place it. Some believe that pouring concrete directly onto a granular base should be sufficient and that a vapor barrier can cause slabs to curve. Others say that vapor barriers are crucial and that they stop adhesive failures

A vapor barrier is required for concrete pads that will be placed outside or inside heated structures and that will be covered in an impermeable material. Pouring concrete without a vapor barrier allows it to weather naturally where it will be exposed to the elements.

Put a vapor retarder under it, though, if you’re considering possibly enclosing it in a heated construction later on or painting it with an impermeable seal. With this knowledge, you should be able to choose and install vapor barriers more effectively.

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Author: Amanda Arnold

Amanda has been working with ConstructionHow since 2021. Her experience spans over 5 years in the creative niche such as home decor and trends, landscaping, renovations, and custom architectural values. As a home designer expert, she has a keen eye for the latest home improvement trends with accurate facts that readers find impossible to ignore. Being invested in home-building trends is how she has gained her lucrative expertise exploring more to bring a positive ambiance for all homeowners (and even tenants!). Currently, she lives in a beautiful beach home, a source of fascination for her.