R22 insulation is usually a batt 5.5 inches thick, sized to fill a 2×6 wall exactly, though a lighter US version runs 7.5 inches. In other materials, R22 takes about 3.5 inches of closed-cell spray foam or polyiso board, about 4.5 inches of XPS foam board, about 6 to 6.5 inches of blown cellulose and close to 9 inches of blown fiberglass. You’ll mainly see it in 2×6 exterior walls and some floors. One heads-up: the 5.5-inch R22 batt is mostly sold in Canada. In US stores, the 2×6 batts you’ll usually find are R-19, R-21 fiberglass or R-23 mineral wool. There’s also a thicker, lighter 7.5-inch US R-22 batt made for deeper framing.
People often run into “R22” in a building plan, a Canadian product page or an online calculator. Our Grizzly Insulation Co crews insulate 2×6 walls in Denver homes all the time, so here’s what R22 really means and what to buy here.
What Does R22 Insulation Mean?
It means the insulation resists heat flow at a value of 22. Higher numbers slow the heat more. The R-value depends on both the material and its thickness, so R22 can look very different from one product to the next.
If the term is new to you, our page on what R-value means explains it simply.
How Thick Is R22 Insulation in Each Material?
Here’s roughly how much of each material it takes to reach R22:
Material
Approx. R-value per inch
Thickness for R22
Fiberglass or mineral wool batt (Canadian R22)
About R-4
5.5 inches
Standard-density fiberglass batt (US R-22)
About R-2.9
7.5 inches
Closed cell spray foam
About R-6 to R-6.5
About 3.5 inches
Polyiso foam board
About R-6
About 3.5 to 4 inches
XPS foam board
About R-5
About 4.5 inches
Mineral wool board
About R-4.2
About 5.25 inches
Blown cellulose
About R-3.5
About 6 to 6.5 inches
Blown fiberglass
About R-2.5
About 9 inches
Blown products settle a bit, so always follow the bag chart for depth. Our blog on the highest R-value insulation compares materials by R-value per inch.
Is R22 Insulation Sold in the United States?
Yes, but not usually as a 2×6 wall batt. Canadian stores carry 5.5-inch R22 fiberglass and stone wool batts for 2×6 walls. In the US, Johns Manville sells an unfaced R-22 fiberglass batt that’s 7.5 inches thick, meant for wood framing such as floors, ceilings and 2×8 walls. It’s lighter and fluffier, so it needs that extra depth.
The Department of Energy’s guide to types of insulation lists R-19 or R-21 batts for 2×6 walls. Mineral wool makers sell R-23 for the same wall in the US. So if a plan calls for R22, the usual swap here is high-density R-21 fiberglass or R-23 mineral wool.
Where Is R22 Insulation Used in a Home?
The dense 5.5-inch R22 batt is a 2×6 product, so it shows up where the framing is 5.5 inches deep. The lighter 7.5-inch US batt goes in deeper framing, like 2×8 floors and ceilings.
2×6 exterior walls. This is the main use.
Basement walls framed with 2×6 studs, in front of foam board.
Floors over garages and crawl spaces with shallow joists.
Knee walls and attic side walls framed with 2×6 lumber.
It isn’t an attic number. Attics in our climate need far more, as covered below.
Does R22 Meet the Building Code for Walls in Denver?
It covers the cavity part, but new walls need more. The 2021 IECC lists four wall options for climate zone 5. They are R-30 in the cavity, R-20 plus R-5 continuous insulation outside, R-13 plus R-10 outside, or R-20 continuous alone. Denver is in zone 5, and the city’s energy code is based on the 2021 IECC.
An R22 or R-21 batt satisfies the “R-20” part. Add about an inch of foam board or mineral wool board outside the sheathing for the R-5, and the wall meets code. Our guide to the best wall insulation for cold climates shows how those layers fit together.
Is R22 Insulation Enough for an Attic?
No. Attics in a cold climate need R-49 to R-60, more than twice R22. Using a wall-sized batt in the attic is one of the most common mistakes we see in older Denver homes.
People sometimes say “heat rises, so any attic insulation is plenty.” That one gets repeated a lot, but it has nothing behind it. Heat flows from warm to cold in every direction, and the attic is just where it escapes most easily. See our guide to R49 insulation for what a proper attic layer looks like.
Is R22 Better Than R19 or R21?
Yes, by a little, as long as it fits the wall. All three are made for 2×6 walls, but R-19 batts are actually 6.25 inches thick. Squeezed into a 5.5-inch wall, an R-19 batt loses some of its rating. R-21 and R22 are made for 5.5 inches, so they fill the space without squeezing.
The difference between R-21 and R-22 is small. In our experience, a well-fitted R-21 batt beats a sloppily installed R-22 every time. Gaps and squashed spots cost far more than one R point.
How Does R-22 Compare to Other Common R-Values?
R-22 sits in the middle of the range. A quick lineup:
R-13 and R-15: 2×4 walls. See our blog about R-15 insulation.
For most 2×6 walls here, we reach for R-21 high-density fiberglass or R-23 mineral wool. Fiberglass is the budget pick and fits well when it’s cut carefully. Mineral wool costs a bit more, but it’s stiffer, stays tight against the studs and handles fire and sound better.
Which one makes sense depends on the room. Bedrooms, shared walls and walls next to the garage are worth the upgrade to mineral wool. Plain exterior walls in a basement remodel do fine with R-21 fiberglass. Either way, the air sealing around outlets, plates and windows matters as much as the batt.
Our big day-to-night swings put walls through a lot of heating and cooling. A batt that fills the cavity completely, with no gaps at the top plate, handles that far better than a slightly higher number that was stuffed in. If you’re comparing walls with your ceiling, ceiling insulation R-value shows how much more the attic needs.
Should You Use Faced or Unfaced R22 Insulation?
It depends on the wall and the climate. Faced batts have a kraft paper layer that slows moisture and usually faces the heated side. Unfaced batts are used when a separate vapor retarder is planned, or when the batt goes against another layer that already controls moisture.
The same way as any wall batt. Measure each cavity and cut the batt slightly bigger so it fits snug. Split it around wires instead of stuffing it behind them, and notch it around outlet boxes. Make sure it touches the top and bottom plates with no gaps.
Yes. About 3.5 inches of closed cell spray foam reaches roughly R21 to R23, which fills a 2×4 wall. That’s one way to get 2×6-level R-value in a thinner wall during a remodel. It costs more than batts, but it also seals air leaks. Our blog on closed cell spray foam R-value shows the depth chart.
Conclusion
R22 insulation is a wall-sized number built for 5.5-inch cavities. In the US, R-21 fiberglass or R-23 mineral wool does the same job. Use it in 2×6 walls and similar spaces, add outside insulation for new builds, and save the much deeper layers for the attic. For the full picture, see how much insulation you need.
Planning a remodel or new walls in your Denver home? Grizzly Insulation Co can help you pick the right batt. We’re BPI Certified and an Xcel Energy rebate partner.
How Thick R22 Insulation Is and Where It Is Used in a Home
R22 insulation is usually a batt 5.5 inches thick, sized to fill a 2×6 wall exactly, though a lighter US version runs 7.5 inches. In other materials, R22 takes about 3.5 inches of closed-cell spray foam or polyiso board, about 4.5 inches of XPS foam board, about 6 to 6.5 inches of blown cellulose and close to 9 inches of blown fiberglass. You’ll mainly see it in 2×6 exterior walls and some floors. One heads-up: the 5.5-inch R22 batt is mostly sold in Canada. In US stores, the 2×6 batts you’ll usually find are R-19, R-21 fiberglass or R-23 mineral wool. There’s also a thicker, lighter 7.5-inch US R-22 batt made for deeper framing.
People often run into “R22” in a building plan, a Canadian product page or an online calculator. Our Grizzly Insulation Co crews insulate 2×6 walls in Denver homes all the time, so here’s what R22 really means and what to buy here.
What Does R22 Insulation Mean?
It means the insulation resists heat flow at a value of 22. Higher numbers slow the heat more. The R-value depends on both the material and its thickness, so R22 can look very different from one product to the next.
If the term is new to you, our page on what R-value means explains it simply.
How Thick Is R22 Insulation in Each Material?
Here’s roughly how much of each material it takes to reach R22:
Blown products settle a bit, so always follow the bag chart for depth. Our blog on the highest R-value insulation compares materials by R-value per inch.
Is R22 Insulation Sold in the United States?
Yes, but not usually as a 2×6 wall batt. Canadian stores carry 5.5-inch R22 fiberglass and stone wool batts for 2×6 walls. In the US, Johns Manville sells an unfaced R-22 fiberglass batt that’s 7.5 inches thick, meant for wood framing such as floors, ceilings and 2×8 walls. It’s lighter and fluffier, so it needs that extra depth.
The Department of Energy’s guide to types of insulation lists R-19 or R-21 batts for 2×6 walls. Mineral wool makers sell R-23 for the same wall in the US. So if a plan calls for R22, the usual swap here is high-density R-21 fiberglass or R-23 mineral wool.
Where Is R22 Insulation Used in a Home?
The dense 5.5-inch R22 batt is a 2×6 product, so it shows up where the framing is 5.5 inches deep. The lighter 7.5-inch US batt goes in deeper framing, like 2×8 floors and ceilings.
It isn’t an attic number. Attics in our climate need far more, as covered below.
Does R22 Meet the Building Code for Walls in Denver?
It covers the cavity part, but new walls need more. The 2021 IECC lists four wall options for climate zone 5. They are R-30 in the cavity, R-20 plus R-5 continuous insulation outside, R-13 plus R-10 outside, or R-20 continuous alone. Denver is in zone 5, and the city’s energy code is based on the 2021 IECC.
An R22 or R-21 batt satisfies the “R-20” part. Add about an inch of foam board or mineral wool board outside the sheathing for the R-5, and the wall meets code. Our guide to the best wall insulation for cold climates shows how those layers fit together.
Is R22 Insulation Enough for an Attic?
No. Attics in a cold climate need R-49 to R-60, more than twice R22. Using a wall-sized batt in the attic is one of the most common mistakes we see in older Denver homes.
People sometimes say “heat rises, so any attic insulation is plenty.” That one gets repeated a lot, but it has nothing behind it. Heat flows from warm to cold in every direction, and the attic is just where it escapes most easily. See our guide to R49 insulation for what a proper attic layer looks like.
Is R22 Better Than R19 or R21?
Yes, by a little, as long as it fits the wall. All three are made for 2×6 walls, but R-19 batts are actually 6.25 inches thick. Squeezed into a 5.5-inch wall, an R-19 batt loses some of its rating. R-21 and R22 are made for 5.5 inches, so they fill the space without squeezing.
The difference between R-21 and R-22 is small. In our experience, a well-fitted R-21 batt beats a sloppily installed R-22 every time. Gaps and squashed spots cost far more than one R point.
How Does R-22 Compare to Other Common R-Values?
R-22 sits in the middle of the range. A quick lineup:
Which R22 Alternative Works Best in Denver Homes?
For most 2×6 walls here, we reach for R-21 high-density fiberglass or R-23 mineral wool. Fiberglass is the budget pick and fits well when it’s cut carefully. Mineral wool costs a bit more, but it’s stiffer, stays tight against the studs and handles fire and sound better.
Which one makes sense depends on the room. Bedrooms, shared walls and walls next to the garage are worth the upgrade to mineral wool. Plain exterior walls in a basement remodel do fine with R-21 fiberglass. Either way, the air sealing around outlets, plates and windows matters as much as the batt.
Our big day-to-night swings put walls through a lot of heating and cooling. A batt that fills the cavity completely, with no gaps at the top plate, handles that far better than a slightly higher number that was stuffed in. If you’re comparing walls with your ceiling, ceiling insulation R-value shows how much more the attic needs.
Should You Use Faced or Unfaced R22 Insulation?
It depends on the wall and the climate. Faced batts have a kraft paper layer that slows moisture and usually faces the heated side. Unfaced batts are used when a separate vapor retarder is planned, or when the batt goes against another layer that already controls moisture.
Our guide to faced vs unfaced insulation explains which one fits where.
How Do You Install R22 Batts Correctly?
The same way as any wall batt. Measure each cavity and cut the batt slightly bigger so it fits snug. Split it around wires instead of stuffing it behind them, and notch it around outlet boxes. Make sure it touches the top and bottom plates with no gaps.
Our batt insulation crews follow those steps on every 2×6 wall they fill. For closed walls, blown fiberglass insulation or dense-pack cellulose is the better route.
Can You Reach R22 With Spray Foam in a 2x4 Wall?
Yes. About 3.5 inches of closed cell spray foam reaches roughly R21 to R23, which fills a 2×4 wall. That’s one way to get 2×6-level R-value in a thinner wall during a remodel. It costs more than batts, but it also seals air leaks. Our blog on closed cell spray foam R-value shows the depth chart.
Conclusion
R22 insulation is a wall-sized number built for 5.5-inch cavities. In the US, R-21 fiberglass or R-23 mineral wool does the same job. Use it in 2×6 walls and similar spaces, add outside insulation for new builds, and save the much deeper layers for the attic. For the full picture, see how much insulation you need.
Planning a remodel or new walls in your Denver home? Grizzly Insulation Co can help you pick the right batt. We’re BPI Certified and an Xcel Energy rebate partner.
Call (303) 854-6221 to get started.
Frequently Asked Questions
About 5.5 inches for the dense wall batt, or 7.5 inches for the lighter US batt.
Not as a batt. It’s too thick. Use R-13 or R-15 batts, or closed cell spray foam.
For 2×6 walls, R-21 fiberglass or R-23 mineral wool batts.
Yes, in a 2×6 framed wall in front of foam board, not pressed against bare concrete.
It’s below the R-30 code number for floors. Some floors may qualify by filling the joist cavity, so check with your building department.
Yes. RSI 3.87 is the metric version of R22.