Owens Corning AttiCat R-60 Coverage Chart: Bags per 1,000 Sq Ft

How many bags of Owens Corning AttiCat blown fiberglass you need to hit R-60 at 20.5 inches installed depth, from the published AttiCat PDS coverage row. Sized for deep-energy retrofits, Zone 7-8 attics, and ENERGY STAR new-construction targets.

AttiCat Coverage Chart — R-13 Through R-60

The Owens Corning AttiCat PDS publishes coverage rows at R-13, R-19, R-22, R-26, R-30, R-38, R-44, R-49, and R-60. The R-60 row is directly published — not interpolated like some intermediate values — so the numbers below come straight from the manufacturer chart per Owens Corning AttiCat PDS (ASTM C687 tested). Verify against the chart on your specific bag before purchasing.

R-60 is a published row in the Owens Corning AttiCat PDS — not interpolated. Implied R-per-inch at R-60 = 60 ÷ 20.5 = 2.93 R/in (vs the conservative 2.79 R/in derived at R-30); both values appear in the same PDS due to fiberglass settled-density variation across coverage tiers. Per FTC R-Value Rule 16 CFR Part 460, coverage charts use settled-depth basis; AttiCat fiberglass does not settle appreciably.

How the R-60 Bag Count Math Works

AttiCat fiberglass provides a settled R-per-inch of 2.79 (derived from the published Owens Corning AttiCat PDS R-30 row at 10.75 in, ASTM C687). The R-60 row implies a slightly higher 2.93 R/in due to fiberglass settled-density characteristics at deeper installs — the engine on the Blown-In R-Value Calculator uses the conservative 2.79 R/in for top-up estimates so customers don't under-buy. For new-build R-60 targets where you are working from a bare deck, use the published 31.8 sqft/bag rate directly.

AttiCat R-60 Bags by Attic Size

Bag counts for common attic sizes targeting R-60 (bare attic, 10% buffer included) derived from the published Owens Corning AttiCat PDS R-60 coverage rate of 31.8 sqft/bag. If your bag's coverage chart lists different sqft/bag values, treat the bag label as authoritative and recalc using those numbers.

Depth is constant at 20.5 in; only bag count scales with area. For top-up scenarios from any existing depth, use the delta formula above or the Blown-In R-Value Calculator.

Why Target R-60: Deep-Energy Retrofits and New Construction

R-60 is the highest standard attic R-value in residential construction. Three concrete reasons drive homeowners and builders to target R-60 specifically rather than the more common R-49:

• DOE Zone 7 and Zone 8 recommendation: per energy.gov, R-60 is the DOE recommended attic level for Zones 7 and 8 (Minneapolis MN, Duluth MN, Burlington VT, interior Alaska). If you live in one of these zones, R-60 is not overinsulation — it is the cost-effective recommendation for your climate.
• ENERGY STAR new-construction target: the ENERGY STAR Recommended Levels tool returns R-60 across most US ZIP codes for new construction. If you are building new and chasing the ENERGY STAR new-homes program label, R-60 is the attic spec.
• Deep-energy retrofit programs: utility-funded retrofit programs in Zone 5 and Zone 6 jurisdictions (Northeast, upper Midwest, Mountain West) often pair air-sealing with R-60 attic insulation for the highest energy-savings tier. Rebate tiers may step up significantly above R-49 — check your utility's program before sizing the order.

If you are in DOE Zone 1, 2, 3, or 4 (most of the South + lower Midwest), R-60 exceeds the DOE recommendation for your climate. R-38 to R-49 is more cost-effective; the R-49 to R-60 marginal cost of approximately 8 extra bags ($541 per 1,000 sq ft) is unlikely to pay back in heating savings outside of cold-climate zones.

No Settling Means R-60 Stays R-60 (Critical at 20.5 in Depth)

Blown fiberglass does not settle appreciably per the Owens Corning AttiCat PDS — once you install AttiCat to 20.5 inches, that depth stays R-60 for the life of the install. This matters more at R-60 than at lower R-values: blown cellulose at R-60 depth (~16.1 in settled) typically needs to be installed at ~17.3 in to absorb the ~7% chart-implied settling per FTC R-Value Rule 16 CFR Part 460 settled-depth basis. With AttiCat, set gauge sticks to 20.5 inches and blow to that mark.

R-49 vs R-60: Which AttiCat Target Should You Choose?

R-49 is the standard cold-climate attic minimum; R-60 is the deep-energy retrofit and new-build maximum. The marginal step from R-49 to R-60 is real money at scale — about 8 more bags and $541 more per 1,000 sq ft — so the decision matters. Here is the side-by-side from the published Owens Corning AttiCat PDS rows:

Decision rule: Zone 7-8 or new-build chasing ENERGY STAR → R-60. Zone 5-6 with adequate rafter clearance + utility rebate → R-60. Zone 5-6 without rebate or with tight rafters → R-49. Zone 1-4 → R-38 to R-49 is more cost-effective (see the AttiCat R-40 coverage chart for the common Zone-4 top-up target).

AttiCat R-60 Cost Estimate — DIY and Contractor

As of May 2026, Owens Corning AttiCat 27.5 lb bags retail at approximately $67.58 per bag at Home Depot (SKU 100541755; bulk price $64.20 for 30 or more bags). The expanding-bagger blower is free with 10 or more bags — R-60 orders always qualify since the smallest typical job exceeds 30 bags. Lowe's pricing was not confirmed this session; verify before purchasing.

• 1,000 sq ft at R-60: 36 bags (with buffer) x $67.58 = ~$2,433 in materials (bulk rate kicks in: 36 x $64.20 = $2,311)
• 1,500 sq ft at R-60: 53 bags x $64.20 (bulk) = ~$3,403 in materials
• 2,000 sq ft at R-60: 70 bags x $64.20 (bulk) = ~$4,494 in materials
• 3,000 sq ft at R-60: 105 bags x $64.20 (bulk) = ~$6,741 in materials

Prices: HD product page 2026-05-17; regional variance applies. Confirm bulk rate ($64.20/bag for 30+) at the register. Bulk threshold is easily cleared on any R-60 order.

Contractor-installed blown fiberglass at R-60 typically runs $1.75 to $2.75 per sq ft, or $1,750 to $2,750 per 1,000 sq ft including labor. DIY materials at ~$2,311 per 1,000 sq ft (bulk-priced) sit at the upper end of that contractor range — DIY savings on R-60 jobs are smaller than on lower R-values because material cost scales while labor stays roughly constant. The DIY win at R-60 is control over air-sealing prep, not material savings.

AttiCat may qualify for the federal Section 25C Energy Efficient Home Improvement Credit (30% of material cost, up to $1,200 annual cap on insulation). Verify current status at irs.gov. A 30% credit on $2,433 (1,000 sq ft) = $730 — below the cap. A 30% credit on $4,494 (2,000 sq ft) = $1,348 — over the cap, so the credit maxes at $1,200. Plan accordingly if you are stacking with HVAC or window upgrades that also pull from the 25C envelope.

Climate Zone and Code Context for R-60

R-60 is a DOE recommended target for the coldest US climate zones and an ENERGY STAR new-construction target across most ZIP codes. The table below shows where R-60 sits relative to DOE recommendations by zone, sourced from energy.gov and energystar.gov (verified 2026-06-03):

DOE retrofit targets at energy.gov are cost-effectiveness recommendations, not prescriptive code. Look up your zone by ZIP at energystar.gov; your jurisdiction may enforce IECC N1102.1 — confirm the adopted IECC edition and R-value minimum with your local building department before any permitted project. For new construction targeting the ENERGY STAR new-homes program, the ENERGY STAR attic spec is R-60 across most US ZIP codes regardless of climate zone — the ENERGY STAR target is more ambitious than the prescriptive DOE recommendation.

Rafter Baffles Critical at R-60 Depth

At 20.5 inches of installed blown fiberglass, baffles are non-negotiable. IRC §R806 (verify locally-adopted edition with your local building department) sets the attic free-vent-area requirement at 1:150 (1 sq ft per 150 sq ft of attic floor). Install cardboard or rigid-foam baffles at every eave bay, extending at least 21 inches above the deck (to clear the planned 20.5-inch insulation level) before blowing. In standard 2x10 rafter bays you have ~9.25 in of vertical room above the top plate — raised-heel trusses or extended baffles are usually required to maintain the 1-inch soffit airway at R-60 depth. Without baffles, fiberglass encroaches on the soffit-vent airway and creates ice-dam risk in Zones 5-8.

AttiCat R-60 DIY Install Checklist

Follow these steps in order for a compliant R-60 DIY AttiCat install. R-60 is a high-stakes install — the 20.5 in depth amplifies any air-sealing or baffle shortcuts.

1. Confirm your DOE climate zone is 5-8 OR you are building new to ENERGY STAR — Look up your zone by ZIP at energystar.gov. Zone 1-4 retrofits without ENERGY STAR new-build context: R-60 is likely overinsulation — see the AttiCat R-40 coverage chart or step down to R-49.
2. Verify rafter-bay clearance — Measure from deck to roof underside at the eave. You need clear 21 in above the deck for baffles. Tight 2x6 or 2x8 rafter bays may force a step down to R-49 or require extended baffles.
3. Measure existing depth and calculate delta — Push a ruler to the deck at 3+ locations. Multiply average depth (in) by 2.79 to estimate existing R-value. Subtract from 60 to get your delta R. Use the Blown-In R-Value Calculator for an estimated bag count.
4. Air-seal first — do not skip this at R-60 — Seal top plates, electrical penetrations, recessed lights, and duct boots with low-expansion spray foam or fire-rated caulk. Air-sealing is the highest-value step in any deep-energy retrofit; skipping it cuts effective R-value 20 to 30%, wasting much of the R-60 premium over R-49.
5. Install rafter baffles to 21 in minimum — Cardboard or rigid-foam baffles at every eave bay, extending at least 21 inches above the deck. Required per IRC §R806 (verify locally-adopted edition with your local building department) . Stapled at the rafters, not at the top plate.
6. Set depth gauge sticks at 20.5 in — Insert every 4-6 feet across the deck before blowing. AttiCat does not settle — installed depth is final depth.
7. Reserve the AttiCat expanding-bagger blower at HD — NOT the standard cellulose blower. Free with 10+ bags. Confirm availability before purchasing — R-60 orders are large enough that backorders or blower-unavailability stall the entire job.
8. Blow in 2 passes from eave to ridge — First pass for base depth (~12 in); second pass to hit the 20.5-inch gauge-stick marks. No overfill needed. Plan a 2-day install for any attic above 1,500 sq ft — R-60 takes longer than R-49 due to depth.

Common AttiCat R-60 Installation Mistakes

R-60 amplifies the cost of every common DIY AttiCat install error because depth + bag count are both 60% higher than R-40. The four most expensive mistakes:

• Targeting R-60 in Zone 1-4 without an ENERGY STAR new-build justification — The most expensive zone-selection error. R-60 in Zone 3 costs 12 to 14 more bags than the DOE-recommended R-38 — about $810 to $945 in materials per 1,000 sq ft — with payback well beyond 20 years in mild climates. Verify your DOE zone before sizing.
• Standard rafter baffles too short at 20.5 in depth — Standard baffles ship in 14-inch or 16-inch lengths. At R-60 depth, those are too short — the fill spills over the baffle top into the soffit airway. Buy extended (22+ inch) baffles or stack standard baffles with the seam taped, or step down to R-49.
• Skipping air-sealing and assuming R-60 makes up for it — Blown insulation slows conductive heat transfer but does not block convective air movement through open top plates, duct penetrations, and recessed light gaps. At R-60 with significant stack-driven bypass, effective performance can drop to R-30 or lower — you paid for R-60 and got R-30. Air-seal first; it is the highest-ROI step in any deep-energy retrofit.
• Ordering 32 bags expecting it to be enough for R-60 — The published 31.8 sqft/bag rate ceilings at 32 bags but provides NO buffer for obstructions, joist depth, or settling-around-objects. Order 36 bags minimum (rate + 10%); 40 bags for heavily obstructed attics. The marginal cost of 4 extra bags ($270) is insurance against a return trip when you run short mid-blow.
• Blowing in one pass instead of two at 20.5 in depth — Single-pass blowing at R-60 depth produces uneven coverage with thin spots that drop performance significantly. Two passes (~12 in first pass, then top-up to 20.5 in mark) is the only reliable way to hit consistent depth across the full attic.

Frequently Asked Questions

How many AttiCat bags do I need per 1,000 sq ft at R-60?

Coverage rate 31.8 sqft/bag per the published Owens Corning AttiCat PDS R-60 row → 32 bags = minimum integer count; buy 36 bags (rate + 10% buffer). Confirm against the chart on your specific bag before purchasing.

What is the installed depth of AttiCat at R-60?

20.5 inches installed (no settling — that is also the final depth) per the Owens Corning AttiCat PDS R-60 row. Set gauge sticks to 20.5 inches before blowing. Verify rafter-baffle clearance is at least 21 inches above the deck before starting.

When should I target R-60 instead of R-49?

Target R-60 when: (a) you are in DOE Zone 7 or 8 (Minneapolis, Burlington, Duluth, interior Alaska) where R-60 is the DOE recommendation per energy.gov; (b) you are in Zone 5 or 6 and pursuing a deep-energy retrofit or chasing utility rebate tiers above R-49; or (c) you are building new and targeting the ENERGY STAR new-homes program attic spec. Otherwise R-49 is more cost-effective.

How much does AttiCat R-60 cost in materials per 1,000 sq ft?

At $67.58 per bag at Home Depot (May 2026), 36 bags with the 10% buffer = approximately $2,433 in materials per 1,000 sq ft. At the bulk rate of $64.20/bag (30+ bags), it drops to $2,311. Blower is free with 10+ bags. Verify pricing at your local store.

Is R-60 worth the extra cost vs R-49?

The marginal cost of R-60 over R-49 at 1,000 sq ft is approximately 8 more bags and $541 more in materials for an R-11 jump. In DOE Zones 7 and 8, R-60 is the recommended level and pays back via reduced heating cost over approximately 7 to 10 years per DOE estimates. In Zones 5 to 6, the R-49 to R-60 jump is a discretionary deep-energy retrofit choice — worthwhile if utility rebates cover the gap. In Zones 1 to 4, R-60 is overinsulation against the DOE recommendation.

Estimates only — verify with your local building authority and a qualified contractor before construction. See our full disclaimer.