Shopping for insulation means wading through R-numbers, and R22 is one you will see on every batt package in Canada. R22 insulation simply means insulation rated at R-22: a measure of how well it resists heat flow. The higher the number, the slower heat escapes through it.
This guide explains what the R-22 rating means in plain terms, where it is used, how thick it needs to be, and how it compares to the R-values your building code actually requires. No jargon, just what a homeowner needs to know.
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Table of Contents
- 1. What the R-22 Rating Actually Means
- 2. Batts and Rolls
- 3. Blown-In Alternatives
- 4. Attic Floors
- 5. Attic Knee Walls
- 6. Wall Cavities
- 7. Basements and Crawl Spaces
- 8. Ceilings Between Floors
- 9. Dealing With Old Insulation
- 10. Buying the Right Product
- FAQs
1. What the R-22 Rating Actually Means
The R-value measures resistance to heat flow: R-22 resists about twice as well as R-11. It is a property of the whole installed layer, not the material alone, so thickness matters as much as the product. A standard R-22 batt is about 14 cm thick, made to fill a 2x6 wall cavity.
Canada also uses RSI, the metric twin: R-22 equals about RSI 3.9. You will see both on packaging. Do not overthink the conversion: what matters is matching the rating to the spot, because an R-22 batt squashed into a smaller cavity no longer performs at R-22.
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2. Batts and Rolls
The classic R-22 product is a fibreglass or mineral wool batt sized for 2x6 studs, 38 cm or 60 cm wide. Mineral wool batts are denser, cut cleanly with a bread knife, and resist fire and moisture better; fibreglass is lighter and cheaper. A bag of eight batts covers about 8 square metres and costs $60 to $90 CAD.
Fit matters more than brand. Batts should fill the cavity fully without compression or gaps: compress a 14 cm batt into 9 cm and you lose roughly a third of the rating. Cut neatly around wires and boxes instead of stuffing, and split batts to go behind pipes rather than in front.
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3. Blown-In Alternatives
Blown-in cellulose or fibreglass can also reach R-22 and beyond in an attic: it just takes about 20 cm of depth. A blowing machine fluffs the material through a long hose, filling every nook around wires and pipes. Most rental counters lend the blower free with a minimum bag purchase.
Blown-in wins in messy attics with lots of obstructions, while batts win in clean open cavities. For winterizing a cottage, blown-in is often the faster job since old cottages have cramped, irregular framing. Either way, air-seal the attic floor first.
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4. Attic Floors
Here is the surprise for many homeowners: R-22 is not enough for an attic in Canada. Current codes in most provinces call for around R-50 to R-60 in ceilings, more than double. R-22 batts in an attic floor are a start, not a finish.
The usual fix is layering: lay R-22 batts between the joists, then blow another 20 cm of cellulose over the top, perpendicular to the joists. The blown layer covers the joists themselves, which are thermal bridges leaking heat. Total material for a 100-square-metre attic runs $1,500 to $3,000 CAD installed.
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5. Attic Knee Walls
Knee walls, the short walls under sloped attic ceilings, are classic weak spots. Builders often stuff them with whatever was handy, leaving gaps you can feel on a cold day. R-22 batts fit these cavities well when the framing is 2x6.
Cover the attic side with a rigid air barrier, even just housewrap stapled tight, so wind does not blow through the batts. Unfaced batts plus an air barrier outperform faced batts with gaps. It is fiddly work in a cramped space, so budget a full day.
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6. Wall Cavities
The natural home of R-22 batts is the 2x6 exterior wall, the standard for new Canadian houses for decades. A full, well-fitted batt plus sheathing and drywall gives a wall in the low R-20s overall, since the studs themselves conduct heat and drag the average down.
That framing penalty is why many builders now add rigid foam outside the sheathing too. If you are opening walls during a renovation, it is the perfect moment: warming a garage or an addition follows the same recipe of batts inside plus foam outside.
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7. Basements and Crawl Spaces
Below grade, moisture changes the rules. Fibreglass batts can work on basement walls only if the concrete is dry and the assembly can dry inward, which is a big if. Mineral wool batts handle damp better and do not feed mould, making them the safer batt choice underground.
In crawl spaces, wear full protective gear: respirator, goggles, gloves, and coveralls. Fibres and dust are miserable without them. Support batts so they stay in contact with the floor above; sagging batts leave an air gap that kills performance.
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8. Ceilings Between Floors
Insulating between floors is about sound and fire as much as heat. R-22 batts in a basement ceiling quiet footsteps and contain a furnace-room fire longer. The install is overhead work, so cut batts slightly wide and friction-fit them: gravity is not your friend here.
Hold them up with wire stays or strapping every 40 cm until the drywall goes on. Do not block soffit vents or combustion air openings for the furnace and water heater: starving them of air is dangerous. When in doubt, leave the mechanical room ceiling to a pro.
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9. Dealing With Old Insulation
Many attics still hold a thin layer of old loose fill, sawdust, or vermiculite from decades ago. If it is dry, undisturbed, and intact, new insulation can usually go right over it. Do not stir up old material until you know what it is.
Vermiculite may contain asbestos: if you see grey-brown pebble-like granules, stop and get it tested before touching anything. Contaminated removal needs a licensed abatement crew. Sorting the old layer properly is the unglamorous step that makes the new work last.
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10. Buying the Right Product
Match the batt to your framing: 2x6 walls take the 14 cm R-22 batt, while 2x4 walls take R-12 or R-14. Check the package label for width, 38 or 60 cm, to match your stud spacing. Buying the wrong width means trimming every batt, which wastes time and material.
Mineral wool costs more per bag but cuts cleaner and irritates skin less. Fibreglass is the budget pick and performs fine when installed carefully. Either way, buy 10 per cent extra: miscuts and odd cavities eat into the count faster than you expect.
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FAQs
Where can I buy R22 insulation batts?
Any building supply store in Canada stocks them: Home Depot, Lowe's, Rona, and local lumber yards. A bag of eight batts runs $60 to $90 CAD. Call ahead for mineral wool, since some stores stock less of it.
Is R22 enough for an attic in Canada?
No. Most provinces require R-50 to R-60 in attic ceilings. R-22 batts are a good base layer between joists, with blown-in insulation on top to reach the full target.
Can I compress an R-22 batt into a 2x4 wall?
You can, but you should not. Squeezing it down drops the performance toward R-15 and wastes money. Use the right batt for the cavity: R-12 or R-14 for 2x4 walls.
Fibreglass or mineral wool?
Mineral wool resists fire, water, and sound better and is easier to cut neatly. Fibreglass costs less. Both hit R-22 at the right thickness. Choose mineral wool for basements and noisy rooms, fibreglass where budget rules.
Do I need a vapour barrier with R-22 batts?
In most Canadian climate zones, yes: poly on the warm side of exterior walls is standard practice. Some builders now use smart membranes or vapour-retarding paint instead. Follow your local code.
Final Thoughts
R-22 is a workhorse rating, not a magic number. It belongs in 2x6 walls, as a base layer in attics, and anywhere a 14 cm cavity needs filling. Match it to the spot, install it without gaps or compression, and pair it with air sealing. With the building science sorted, the fun part starts: making those warm rooms beautiful, as these Winnipeg winter home decor ideas show.
Sources
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Photo: Wikimedia Commons
Photo: Wikimedia Commons
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