Should I put a vapor barrier on my basement walls?

Asked By: Mont Klapholtz | Last Updated: 28th February, 2020
Category: home and garden indoor environmental quality
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Before framing the walls of your basement, install a moisture barrier to prevent water and moisture from entering the wall cavity. Here are your three best options. But if you use fiberglass insulation batts, then a moisture barrier will prevent water and moisture from entering your walls and creating mold and mildew.

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Consequently, should you put plastic on basement walls?

Visqueen on Walls A common question people have when finishing a basement is: "Should I use visqueen or plastic sheeting on one side or the other of the framed basement walls?" The answer is no. Plastic will keep moisture from moving through the wall.

Beside above, what type of insulation should be used in a basement? The most commonly used insulation materials in the basement include spray foam, fiberglass, and foam board. In older homes, the basement many times is left uninsulated. This allows air from the outside to get into the rim joist, basement ceiling, and exposed walls.

Additionally, is vapor barrier necessary?

The purpose of vapour barriers 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.

Should you insulate your basement walls?

Walls. Basement walls should be insulated with non-water sensitive insulation that prevents interior air from contacting cold basement surfaces—the concrete structural elements and the rim joist framing. The best insulations to use are foam based and should allow the foundation wall assembly to dry inwards.

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Do I need vapor barrier on basement walls?

A basement vapor or moisture barrier is installed during the new construction of a home or the remodeling of a basement. The material is stapled to the frame of a basement wall before it is finished with plaster or drywall. A vapor barrier is also helpful to keeping a basement insulated and warm.

Do basement walls need to breathe?

It behaves as a moisture trap and can also hide structural problems and cracks in the foundation. Bottom line: basement walls need to breathe too.

Where does vapor barrier go in basement wall?

Not to be confused with a vapor barrier—which is placed on the warm side of the wall just in front of the insulation and behind the drywall— a moisture barrier goes against the basement wall and behind the insulation and framing. The best option for insulating a basement is to use spray foam insulation.

Should you put plastic between insulation and drywall?

The standard installation of a plastic vapor barrier is between the studs and the drywall, but there are some exceptions to this. In exterior walls that are below-grade, like basement walls, plastic should not be used at all.

How far should studs be from basement wall?

Studs should be placed 16 inches apart on centre. Once all the studs are in place, use your level to make sure that the wall is straight and the studs are flush.

Where should vapor barrier be installed?

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.

What happens if you don't use vapor barrier?

If water vapor diffuses or infiltrates into the wall cavity and finds the cool surface, moisture problems can occur. Of course, you can have moisure problems here even without the exterior vapor barrier because of what Bill Rose calls the rule of material wetting.

Do vapor barriers cause mold?

The original reason for using vapor barriers was a good one: to prevent wall and ceiling assemblies from getting wet. This can lead to significant moisture problems and mold; problems occur when walls get wet during construction or more often throughout the home's life.

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. It's designed to stop the moisture before it can enter the wall cavities. There are two basic types of vapor barriers used with exterior wall insulation. The most common is paper-faced insulation.

What is the purpose of vapor barrier?

A vapor barrier (or vapour barrier) is any material used for damp proofing, typically a plastic or foil sheet, that resists diffusion of moisture through the wall, floor, ceiling, or roof assemblies of buildings to prevent interstitial condensation and of packaging.

Should insulation be covered with plastic?

Fiberglass insulation will not degrade unless exposed to water. The fiber could become airborne if a vent is blowing on it or it is disturbed in some way. It can be covered with a plastic vapor barrier to protect your home air quality. The plastic can be bought at any big box store.

Can paint be used as a vapor barrier?

So what makes a vapour barrier
Plastic and aluminium sheets are well under 1 Perm. Two coats of a good oil paint will provide a vapour barrier of less than 1 Perm as well. There are even some latex vapour barrier primers that will do the job.

Is Drywall an air barrier?

Gypsum board drywall is, itself, a suitable air barrier material. The taping of drywall seams results in a plane of airtightness at the field of the wall. However, several steps must be taken to use this material property to create a continuous and complete air barrier system.

When should I use vapor barrier on floor?

You will need a moisture barrier underlayment when installing:
  1. On a cement subfloor.
  2. On any subfloor that has a chance of moisture coming up and soaking into the flooring.

What R value insulation should I use in my basement?

The basement walls need to be insulated to a minimum value of R-10 for continuous insulation (such as foam plastic insulation) or R-13 for framing cavity insulation based on the component requirements of Table N1102.

Do concrete basement walls need insulation?

Remember, fiberglass does NOT resist moisture, so it's generally a no-no when insulating basements. Closed-cell spray foam is the best way to insulate concrete basement walls. This is because it can achieve a higher R-value, along with excellent moisture resistance, with less thickness required.

Do you need a vapor barrier in the basement?

If you put a polyethylene vapor barrier behind a drywall-covered stud framed wall, then the answer is that water that condenses on the poly will fall onto the wood sill plate, growing mold and eventually rotting it out. Dedicated vapor barriers have no place in a basement wall.