How Many Insulation Removal Bags Do You Need?

An insulation removal vacuum pulls old material out of the attic and sends it straight into a collection bag — it doesn't disappear, so every cubic foot of insulation you remove needs somewhere to go. Under-order and the job stops mid-way while someone runs for more bags. Over-order and you've paid for capacity you didn't use.

Getting a reasonable estimate before the rental starts is the easiest way to keep a removal day moving without surprises.

The bags we supply are sized to match our 14 HP removal vacuum: 72" × 48" with an 8" inlet, holding approximately 75 cubic feet of loose-fill insulation each. They're sold separately from the vacuum rental at $40 CAD per bag, so you only pay for what you actually use.

In practice, a bag rarely fills to a mathematically perfect 75 cubic feet — loose-fill material settles and shifts as it's vacuumed in, so a realistic working capacity is closer to 60–65 cubic feet per bag once it's tied off and ready for disposal.

Start with your attic's floor area in square feet, then measure the average insulation depth in a few spots (it's rarely perfectly even) and convert it to feet — 12" of depth is 1 foot. Multiply area × depth to get the total cubic feet of material you're removing.

Divide that number by roughly 60 cubic feet of realistic per-bag capacity, then round up. For example: a 1,000 sq ft attic with 12" (1 ft) of insulation is about 1,000 cubic feet of material — divided by 60, that's roughly 17 bags. Add a 10–15% buffer for uneven depth or denser pockets, and you'd plan for around 19–20 bags rather than cutting it exactly at 17.

Depth and square footage drive most of the estimate, but material type matters too — denser insulation like mineral wool or older, moisture-compacted blown-in material fills a bag faster by weight than light, dry fiberglass, even at the same cubic footage. If your attic has visibly wet, compacted, or contaminated insulation, plan for slightly more bags than the dry-material formula suggests.

Attic obstructions — trusses, ductwork, low clearance areas — also mean the numbers on paper rarely match perfectly, which is part of why the buffer matters more than the exact math.

Bags are billed separately from the vacuum itself. Current rental rates are $380 CAD for the first 24 hours and $280 CAD per additional day, plus $40 CAD per bag used and delivery or pickup priced by location. HST is extra, and a security deposit may apply.

For the 1,000 sq ft / 12" example above, that's roughly 19–20 bags × $40 — about $760–$800 in bags on top of the rental. Running the estimate before you book is what lets you budget the full job accurately instead of getting a bag-cost surprise partway through.

Measure depth in more than one spot; attics almost never have perfectly even insulation, and eave areas or spots with old repairs tend to run deeper than the middle of the floor. When in doubt, round your estimate up rather than down — an unused bag costs nothing if you don't fill it, but a stalled removal while someone sources more bags costs the whole crew time.

If you're not confident measuring depth accurately, send us the attic's approximate square footage and a couple of photos — we can help you land on a realistic bag estimate before your rental starts.