Three Reasons Why It’Second A Bad Idea

Attic in addition to wall insulation is made from the same material as well as expect similar. However, the packaging of insulation will oftentimes specify where it should be used.

Attic and wall insulation differ inward R-values and dimensions together with using loft/attic insulation inwards the walls tin can drive installation issues.

Attic insulation is required to take a much higher R-value than wall insulation. This agency that attic insulation is also thick to install in most wall cavities. It is likewise more expensive.

Differences Between Ceiling too Wall Insulation

The material used inward ceiling together with wall insulation make not differ. For example, fiberglass batts or rolls are a common type of “blanket” insulation that comes both in ceiling/attic format together with in wall format.

The difference is that they are designed to have different densities as well as sizes.

R-Value

R-value refers to the insulation’second thermal resistance; basically, its power to preclude the transfer of rut. The higher the R-value, the more than effective the insulation.

Attic insulation is designed to take a higher R-value. The U.due south. Department of Energy recommends R-thirteen to R-23 for outside walls. But the lowest R-value they recommend for attics is R-xxx, and virtually states autumn into the reach of R-49 to R-sixty for attics.

R-value of attic and wall insulation according to the U.S. Department of Energy.jpg

There is little to no overlap in the R-values of wall together with attic insulation; they are simply designed for dissimilar purposes.

However, when yous accept infinite (such equally in an attic), you tin can layer insulation to increment the R-value. For instance, an R-19 batt addition an R-thirty batt would have an R-value of 49.

Climate Zone map of United States with required R-value for different location with insulation .jpg

High R-values brand a bigger deviation inward the attic, where oestrus rises in addition to escapes. High R-value insulation inward attics tin foreclose up to xc% of estrus transfer, piece high R-value insulation inwards walls prevents up to lx% of rut transfer.

R-value depends on both the cloth from which the insulation is made and the thickness and density of that cloth.

Attics postulate higher R-values as well as tend to accept more than space for insulation, and so attic insulation is ever thicker than wall insulation.

Available Sizes

Pre-ready sizes do non be for liberate-make full or blown-in insulation. Instead, they are installed inwards dissimilar thicknesses for walls in addition to attics.

For batts or rolls, the size of the product is based on the dimensions of the measure wall too R-value of the insulation.

ii×four walls concord R-13 or R-xv batts patch ii×6 walls hold R-nineteen or R-21 batts. They come up inwards criterion widths of xv inches as well as 23 inches. xvi-inch and 24-inch options be for steel stud construction.

R-xxx as well as R-38 batts are about mutual for attic insulation. They tend to come inward widths of xvi inches or 24 inches, which allow them to correspond snugly betwixt standard joist spacing.

Width is standardized, simply length is more variable, peculiarly when it comes to rolls, which you are expected to cutting equally needed.

In add-on to size, wall together with attic insulation come inwards different formats. Let’second compare what y'all mightiness think would live the same format of insulation: fiberglass batts of attic insulation versus fiberglass batts of wall insulation.

Attic insulation batts will be thicker only less stiff, as they call for to fit inward around attic rafters.

Wall cavities have fewer obstructions, then wall batts do non necessitate to live as flexible. In fact, wall batts take to be somewhat stiff to foreclose them from slumping equally they stand vertically in the wall cavity.

Similar principles use to curlicue insulation: the wall version volition live slightly more rigid than the attic counterpart.

three Reasons Why It’s a Bad Idea

1. Insulation May Need to Be Compressed

When y'all attempt to fit thick attic insulation into a narrow wall cavity, you adventure compressing the insulation, which compromises its thermal resistance capabilities.

Fiberglass insulation on attic and walls.jpg

The affect of compression on R-value tin sometimes be confusing. You may accept read that compressing fiberglass batts tin increment the R-value per inch. This makes sense in theory because fewer air pockets hateful less estrus transfer.

However, compressing insulation will bring down the full R-value. For instance, a batt that is rated every bit R-xix at vi inches thick will, if compressed into a 5.v-inch wall, drib to R-eighteen. If compressed into a three.five-inch wall, it will drib to R-14.

Compressing as well much insulation into a wall cavity tin can fifty-fifty place force per unit area on the forest together with drywall.

Even and so, in that location is just about nuance here. Installing the incorrect type of insulation volition lead to large-scale, avoidable compression. But about kid compression inward a few small areas is basically unavoidable.

When installing fiberglass batts around junction boxes inwards a wall, the batts will go packed downward together with compressed inward these areas. As long as y'all fill inwards the area as completely every bit possible piece avoiding further compression, you do non demand to worry nigh these tiddler instances of compression.

What if y'all actually desire to enhance the R-value in your walls but have limited depth to run with?

While you typically don’t need to worry well-nigh increasing the R-value of your walls (every bit we’ll speak almost after), there are around options to view:

Foam board insulation tin pass y'all virtually double the R-value that you would achieve alongside the same depth of virtually other insulating materials. Unlike thick attic insulation, you won’t have issues with slumping or alongside plumbing equipment it into the wall cavity.

Make sure that windows, doors, as well as whatever other gaps are sealed amongst spray foam insulation.

ii. Installation Will Be Difficult

Attic Insulation Is Too Thick

In theory, you lot could pose attic insulation in your walls without negatively impacting your abode’s energy efficiency. However, it tends to be physically hard to effectively install attic insulation in wall cavities equally it is too thick.

On the flip side, wall insulation could live installed inwards an attic with far less physical difficulty. But patch it is physically feasible, it would accept a huge negative bear upon on your domicile’sec free energy efficiency together with power not adhere to free energy codes.

Attic Insulation Might Be Too Wide

Attic insulation typically comes inwards widths of 16 inches together with 24 inches, which matches the dimensions of batts for walls alongside steel stud structure. Still, the depth of the wall too thickness of the insulation would live an effect.

If you lot make not take steel stud construction, attic insulation volition live slightly wider than the criterion 15-inch and 23-inch wall batts.

Steel Stud Construction walls and ceiling

Installing insulation batts that are likewise wide is hard and tin can be specially frustrating if you lot are labor a DIY projection. It will likewise atomic number 82 to the edges existence compressed.

You power demand to cut in addition to adapt the batts or rolls. This takes extra fourth dimension too sometimes leads to waste, especially if you lot’re entirely 1 inch off from the right width. It is easier to buy the appropriate dimensions inwards the first place.

Difference in Stiffness

In add-on to issues inwards size, the slightly unlike textures as well as rigidity of wall and attic batts volition make installation more than frustrating as well as potentially less successful over time.

As nosotros discussed previously, wall insulation is designed to live more stiff so that it tin stand up upward inwards the wall cavity without slumping. Attic insulation is somewhat softer and more flexible, then y'all power take a harder time getting it to stay inwards home, both inward the brusk- in addition to long-term.

three. Wasted Money

The principal argue not to role attic insulation inwards walls is that yous merely don’t demand to. Walls do not need the high R-values that are required inward ceilings.

Hot air rises, and so the attic volition be exposed to hotter air on the outside in the summer together with will require to incorporate hot air inwards the winter. Given express funds together with space—almost people don’t desire 24-inch-thick walls—the ceiling is the about important area to insulate.

Hot air in the attic with insulation.jpg

The Department of Energy’sec R-value guidelines do non take walls to accept fifty-fifty one-half the R-value of ceilings, fifty-fifty if you lot alive inwards the coldest states.

Insulation with greater R-value costs more than.

Installing high R-value attic insulation inward walls will probable non brand enough of a divergence inwards your dwelling house’s energy efficiency to warrant the higher toll.

Furthermore, the extra R-value power not make much of a departure at all—yous power take to compress it which could cancel out the increased insulation capability.