Asked by: Maura Rau
home and garden indoor environmental quality

Can you use unfaced insulation on exterior walls?

Last Updated: 23rd May, 2020

13
Re: Any problems with unfaced insulation on exterior walls? Unfaced will work fine. But you will need a plastic vapor barrier on the inside. Either paper faced insulation to serve as the vapor barrier or a plastic covering will work just fine.

Click to see full answer.

Keeping this in consideration, should I use faced or unfaced insulation on my walls?

When to Use Faced or Unfaced Insulation. Unfaced insulationthe type without paper—is what you would use if you are adding insulation to your attic or to place between floors when living space is above and below. Unfaced is also your best choice for adding soundproofing to interior walls.

Subsequently, question is, do you need a vapor barrier on exterior walls? The short answer is: if your wall doesn't have a vapor retarder, there is no need to worry. Builders worry way too much about vapor diffusion and vapor retarders. It's actually very rare for a building to have a problem caused by vapor diffusion.

Thereof, what kind of insulation do I need for exterior walls?

In the case of walls, the composition can also impact the R-values needed for optimal energy efficiency. The most common insulation materials are fiberglass, cellulose and foam. Insulation types include loose fill, batts, rolls, foam board, spray board and vapor barriers.

Is r11 insulation good for exterior walls?

R11 is for sound and should never be used for exterior walls. It can be, but you're spending money with little benefit. R13 is standard 2x4 insulation.

Related Question Answers

Xinyan Kreuzberger

Professional

Does it matter which way insulation faces?

Regardless of whether fiberglass insulation is installed in a wall, attic, or crawlspace; the paper facing should always face toward the inside of the home. That's because the paper contains a layer of asphalt adhesive which prevents water vapor from passing through it.

Yumalai Quertier

Professional

Do I need a vapor barrier if I use faced insulation?

In climates requiring a vapor retarder on the interior surface, a kraft-faced insulation is usually sufficient. When a loose-fill product such as fiberglass or cellulose is installed, a 4 mil continuous polyethylene sheet or a vapor retarder paint on the interior drywall should be used .

Dayra Pumarega

Explainer

What's the difference between faced and unfaced fiberglass insulation?

Faced insulation is a type of blanket insulation that is typically made of fiberglass. It differs from unfaced insulation only in that it has a vapor barrier (also called vapor retarder) that blocks moisture from moving from one space to another. The vapor barrier is usually made of kraft paper.

Denislava Boligui

Explainer

What is faced insulation used for?

Faced insulation has a vapor barrier or a vapor retarder (the facing) that helps prevent moisture from moving from one space to another. The facing also helps protect the surface, hold the insulation together and fasten the material to building components.

Amalia Suades

Explainer

Can you put plastic vapor barrier over faced insulation?

The special paper lining one side of the insulation is sufficient to block moisture and air. Some builders choose to attach a separate vapor barrier even with faced insulation, however. It doesn't hurt anything. The result, when finished, is a super-insulated wall with a foam vapor barrier instead of sheet plastic.

Paramjeet Godin

Pundit

Is r19 insulation good for exterior walls?

R-19. Although the U.S. Department of Energy rates R-13 insulation as "good" for use in walls in southern areas of the country, it rates R-19 insulation higher, designating it as "great." That is because R-19 insulation provides more thermal insulation than R-13 does.

Claudineia De Juan

Pundit

Do I need a vapor barrier?

In many colder North American climates, vapour barriers are a required part of building construction. You may find that vapour barriers are often not required in warmer climates. And, if installed in the wrong climate or on the wrong side of building materials, a vapour barrier can cause more harm than good.

Dodie Avdievsky

Pundit

What is the best exterior wall insulation?

What Insulation is Best for Exterior Walls?
  • Fiberglass has been used as a home insulation material for decades. It's affordable and effective, making it the go-to choice for many homebuilders and contractors.
  • Cellulose is a great choice for insulating an enclosed existing wall with minimal demolition.
  • Spray foam is applied wet and expands into thick, hard foam.

Vidmantas Gadsch

Pundit

What should the R value be for exterior walls?

Typical recommendations for exterior walls are R-13 to R-23, while R-30, R-38 and R-49 are common for ceilings and attic spaces. See the Department of Energy's (DOE) ranges for recommended levels of insulation below.

Aizhen Groundon

Pundit

Solemnidad Fred

Teacher

Can I use r19 in 2x4 walls?

The normal R19 in a 2x4 wall will actually be far below R19 - probably no better and possibly lower than R13 insulation. R19 in a 2x6 wall does not really give you an R19 wall. It is about a R16 wall because of the feect of the "thermal short circuiting" through the studs.

Roza Groothois

Teacher

How do you insulate an exterior wall without removing drywall?

Exterior Walls
You may add insulation to your walls without removing it by cutting holes into the siding. You can blow spray foam or cellulose into the walls from outside. Just cut a 1 inch to 2-inch hole between the studs at the top of the wall and then spray the insulation into the hole using a hose.

Melcion Hamester

Teacher

How do you insulate an exterior wall from the inside?

You can insulate existing exterior walls either from inside or outside the house. When doing it from outside, the job involves removing some siding panels so that large holes can be bored through the sheathing at the top of wall stud cavities.

Quim Pauker

Reviewer

What is the highest R value for a 2x4 wall?

Fiberglass vats are the standard insulator for 2-inch by 4-inch wall framing, and are rated R-11 through R-15. In order to achieve the higher insulation R-value of R-21 a different type of insulation will be required.

Cleveland Benabbou

Reviewer

Should you put plastic over insulation?

Condensation occurs whenever warm air meets cold air. Without a vapor barrier in place, condensation inside the walls could ruin the insulation and promote the growth of harmful mold and bacteria. Plastic, specifically 6-mil polyethylene plastic, is the most commonly used vapor barrier.

Zandra Goia

Reviewer

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.

Keshia Nierhaus

Reviewer

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.

Sumaila To The First Page

Supporter

What tape do you use for vapor barrier?

PERMINATOR TAPE is a self-adhesive tape, used in conjunction with the application of PERMINATOR underslab vapor barrier. PERMINATOR TAPE is for use in sealing vapor barrier seams and attachment to footings, protrusions, etc.

Eugeniusz Rghioui

Supporter

Should I put plastic over insulation before drywall?

Back years ago, it was always said to NOT put a plastic vapor barrier over the insulation before hanging drywall or whatever material you decide to hang, as it would cause the room or building to act like a greenhouse.