20 Mil Vapor Barrier – Polyethylene Visqueen (USA Made)

$302.00
$151.00

Vapor Barrier – Moisture Protection for Crawl Spaces, Basements, Insulation, & MORE!

Stop moisture, dampness, and condensation before it damages your home or building. Sandbaggy’s 20 Mil Visqueen Vapor Barrier (also known as a vapor moisture barrier) built tough from industrial-grade virgin polyethylene resin. At more than 6x thicker than the standard 3 Mil, this barrier delivers superior protection for crawl spaces, concrete slabs, underlayment, and more. Proudly Made in the USA to ensure lasting quality and support American jobs. Great for a variety of applications:

  • Crawl spaces
  • Basements
  • Under concrete slabs
  • Under flooring / underlayment
  • Walls & Ceilings

Also available: 6 Mil Vapor Barrier , 15 Mil Vapor Barrier

⚠️ Please Note
  • Meets ASTM D4397 - Polyethylene Standard Specifications
  • ***Always check your building codes to ensure you are installing the correct thickness of vapor barrier.
  • Folded Fabric: Rolls will be folded in half to fit within UPS size guidelines. In addition, Rolls may arrive in 2 parts depending on the roll (for example: if you order a 100 feet roll, you may receive two-50 ft pieces).

Specs

  • Country of Origin: USA
  • Material: Virgin Polyethylene (Plastic)
  • Thickness: 20 Mil
  • Size
    • 20 ft x 10 ft (20.9 lbs per roll)
    • 20 ft x 20 ft (41.8 lbs per roll)
    • 20 ft x 50 ft (104.5 lbs per roll)
    • 20 ft x 100 ft (209 lbs per roll)
  • UV Inhibitor: 200 hours
  • Waterproof: Yes
  • Rot Proof: Yes
  • Chemical Resistant: Yes
  • Temperature Range: -60°F - 150°f
  • Meets ASTM D4397 - Polyethylene Standard Specifications
  • Color: Black

Features

  • MADE IN AMERICA – Manufactured in Los Angeles, CA. Support American workers and get a product that won’t tear like cheap imports.
  • 20 MIL THICK PLASTIC – More than 6x thicker than common 3 mil foreign-made sheeting. Built for long-lasting moisture protection.
  • HEAVY DUTY – Exceeds ASTM D4397 standards. Tough enough for construction, industrial, and agricultural applications.
  • TEAR & PUNCTURE RESISTANT – Holds up against rocky soil, foot traffic, and stored items.
  • 100% VIRGIN POLYETHYLENE – Stronger and more reliable than recycled materials.
  • EASY TO CUT & INSTALL – Trim with scissors or a utility knife to fit your exact project needs.
  • REUSABLE – Massive rolls can be reused multiple times until fully worn.

Installaing Your Vapor Barrier

  1. Make sure your subfloor is level, clean, and dry. You do not want anything that could potentially tear the vapor barrier on the floor, such as protruding nails or rocks. If installing over concrete, make sure the moisture emission rates do not exceed 31 lbs. per 1000 square feet per 24 hours as measured by the Anhydrous Calcium Chloride Test,
  2. Apply Butyl Tape to walls, this will ensure when you run your vapor barrier up the walls that it will stick.
  3. Roll Out Your Vapor Barrier: Choose a corner of the room and roll out your vapor barrier sheeting. Make sure your vapor barrier is:
    1. Parallel to the wall
    2. Running in the opposite direction that you plan to install the flooring planks.
    3. 1/2" to 3/4" away from the wall
  4. Overlap your vapor barrier sheeting with another sheet that will run up the wall (covering the 1/2" to 3/4" inch gap). Apply Vapor Barrier Seam Tape to stick the vapor barrier sheets together.
    1. Make sure it runs up the walls around 4-6".
    2. It should overlap the other sheet by 6".
  5. Trim Excess Underlayment: After the flooring is installed, trim, the excess underlayment back to the height of the finished floor. Do this prior to installing a base or molding

FAQs

Is black vapor barrier better than clear?

Black vapor barriers are more effective at stopping moisture evaporation, since the darker color assists in preventing plant growth. When plants grow they emit moisture. This is why black is the typical color choice for weed barriers.

What is the minimum thickness of a vapor barrier?

Most crawl spaces need at least 6 mil, and high-traffic or rocky areas call for 10 mil or more. Under slabs, 10–15 mil is typical. For the toughest conditions, 20 mil offers the highest durability and protection.

Can I use a vapor barrier in my crawl space or basement?

Yes! Our 20 Mil Vapor Barrier is perfect for crawl spaces and basements. It protects against ground moisture, preventing mold and dampness from affecting your insulation, walls, and floor.

Can it be used under concrete or flooring?

Absolutely. Lay it directly under concrete slabs, under underlayment, or beneath finished flooring to create a waterproof shield that keeps moisture from seeping up?

Can it be installed on walls or ceilings?

Yes. You can run the vapor barrier along walls and ceilings in basements, crawl spaces, or other areas to protect insulation and prevent condensation.

Does it protect insulation and building materials?

Definitely. By blocking moisture from the floor, walls, and ceiling, the vapor barrier keeps insulation dry and preserves the longevity of your building materials.

What other names does the product go by?

Also known as: heavy duty plastic sheeting, visqueen vapor barrier, vapor retarder, poly vapor barrier, or polyethylene moisture barrier.