What can I use instead of a vapor barrier?

Author: Owen Blick  |  Last update: Tuesday, February 10, 2026

What can I use as a vapour barrier?
  • Elastomeric coatings.
  • Aluminum foil.
  • Paper-backed aluminum.
  • Polyethylene plastic sheet.
  • Asphalt-coated Kraft paper.
  • Metallized film.
  • Vapour retarder paints.
  • Extruded polystyrene or foil-faced foam board insulation.

What is the alternative to a vapor barrier?

In mild climates, materials like painted gypsum wallboard and plaster wall coatings may be enough to impede moisture diffusion. In more extreme climates, higher-perm vapor diffusion retarders are advisable for new construction.

What happens if you don't have a vapor barrier?

“For minor projects, the absence of a vapor barrier leads to water intrusion, leading to an unstable foundation or a cracked slab.” The American Society for Testing and Materials (ASTM) outlines national standards for underslab vapor barriers.

Can I just use plastic as a vapor 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 aluminum foil a vapor barrier?

Plastic and aluminium foil is the most frequently used of all materials as a vapour barrier. It is usually offered as a roll.

Vapor Barriers: Need one or not?

What can be used as a vapour barrier?

There are a wide number of materials available to create effective vapour barriers, including:
  • Elastomeric coatings.
  • Aluminum foil.
  • Paper-backed aluminum.
  • Polyethylene plastic sheet.
  • Asphalt-coated Kraft paper.
  • Metallized film.
  • Vapour retarder paints.
  • Extruded polystyrene or foil-faced foam board insulation.

Does aluminum foil keep moisture out?

Have you ever noticed that condensation gathers on the foil when it has been used to cover hot food? This is because aluminium foil is moisture-resistant and acts as a vapour barrier. It is also waterproof (water-repellent), draught-excluding and windproof.

Can I use Tyvek as a vapour barrier?

No, DuPont Tyvek is not a vapor barrier. It is breathable, allowing moisture vapor to pass through it.

How do you make a vapor barrier?

Begin at one side of the crawl space and lay down 6-mil or thicker polyethylene plastic over the entire crawl space. Cut the sheets to size, allowing 6 inches or more along walls. Overlap the seams by no less than 12 inches and secure them together with the poly PVC tape.

When should you not use a vapor barrier?

Because a vapor barrier is a low permeable barrier, it keeps moisture from passing through. This is beneficial to keep moisture away from a dry surface but will trap moisture behind it if installed on a water-damaged concrete wall, causing the wall to fail further.

Do I really need a vapour barrier?

Depending on where you live, the vapour barrier will either go on the inner surface of the insulation (if you live in a cold climate) or the outer surface of the insulation (if you live in a hot climate). It's safe to say that a vapour barrier will be needed for almost all projects.

Should you put plastic behind drywall?

Yes, covering your insulation with a vapor barrier plastic before installing drywall is crucial.

Is fi foil a vapor barrier?

The product also can be used as an effective vapor retarder. The aluminum facing also reduces radiant heat transfer for added R-value or as a radiant barrier and is available in 1000 square foot rolls 54″ wide.

What plastic is best for vapor barrier?

The Top 5 Underlayments for Vapor Barriers
  • 8 Mil White/Black Dura-Skrim® Reinforced Plastic Sheeting.
  • 12 Mil White/Black Dura-Skrim® Reinforced Plastic Sheeting.
  • 20 Mil Dura Skrim® Reinforced Plastic Sheeting.
  • VaporBlock® Vapor Barrier.
  • PRO Crawl Barrier.
  • Vapor Barrier Tape.

Is home wrap a vapor barrier?

House wrap is not a vapor barrier. In fact, serious problems can arise from using solid material like polyethylene sheeting as house wrap when a similar vapor barrier is installed to the interior. Moisture can become trapped between those barriers, leading to mold, decay, and other damage.

How do you use a tarp as a vapor barrier?

Lay a heavy plastic tarp -- 6 mil or thicker -- over the entire area. If you must use multiple sheets, overlap them by at least 2 feet. Use stones to hold the plastic down. The plastic acts as a vapor barrier, eliminating much of the migration of water vapor from the ground to the crawl space.

Can any plastic be used as a vapor barrier?

As you can see, thicker polyethylene sheets have very low perm ratings under 0.1, making them viable options as vapor barriers if local codes allow it. Thinner sheets or other plastic types may not meet the requirements.

Do vapor barriers cause mold?

Install a New Vapor Barrier

If your vapor barrier was damaged or not installed correctly, it's important to replace it with a new one. This will help prevent moisture from seeping into your crawl space and creating the perfect environment for mold growth.

Does water go through Tyvek?

With time, or increased water pressure, drops of water will go through Tyvek®. It is suggested that customers should test the performance of Tyvek® for their specific application. Q7: Is Tyvek® breathable? A: Tyvek® is breathable, which means water vapor and gases can go through Tyvek®.

What can I use to cover exposed insulation?

Fabric panels are a cost-effective way to cover exposed insulation. They're an alternative to traditional wall materials and can help improve a room's acoustics. Any kind of permeable fabric will work, and they're easy to install. Stretch fabric over a wooden frame or directly on the wall surface.

What is a good moisture barrier?

A moisture barrier is a material that reduces moisture from moving through other materials. Therefore, a plastic sheet can be a vapor barrier. In fact, plastic (or polyethylene) sheets are a Class I vapor barrier. Meaning, in terms of excellent moisture control, a plastic sheet is one of the best options.

When not to use aluminum foil?

It's important to avoid using aluminum foil with acidic foods like tomato-or vinegar-based dishes, citrus fruits, or marinades containing citrus juices. Acidic ingredients can corrode the foil, causing aluminum to leach into the food, which may result in a metallic taste.

Do you need a vapour barrier with foil insulation?

Typical insulation works in a basement but you have to use a good vapour barrier along with it. This is where foil faced insulation takes its place. The best way to insulate a concrete wall is with foil faced rigid foam boards.

Why wrap cake in saran wrap?

I always always wrap my cakes plastic wrap and refrigerate as soon as they are able to be handled. This way they will sweat a little in the fridge to create more moisture! If you let your cakes cool all the way before wrapping, they're already drying out!

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