R-25 Insulation Rolls
Wholesale fiberglass R-25 in 8" thickness. The IECC wall minimum for Climate Zones 5, 6, and 7 — and the standard ceiling spec in cold climates.
What Is R-25 Insulation?
R-25 insulation is fiberglass batt or roll insulation rated at R-25 thermal resistance under ASTM C518, the U.S. testing standard for insulation performance. The 25 represents resistance to heat transfer: the higher the R-value, the better the material resists heat flow in either direction. R-25 sits above R-19 and below R-30 in the standard fiberglass range.
R-25 is the dominant wall-insulation spec for cold-climate construction in the United States. The 8-inch nominal thickness fits 2x8 framing and is the IECC-recommended minimum for walls in Climate Zones 5, 6, and 7 — most of the northern half of the country, from Colorado and Ohio north through Minnesota and Maine. It is also the most common ceiling and floor-above-unconditioned-space spec in mixed and cold climates regardless of wall R-value.
At Insulation Overstock, R-25 fiberglass insulation is available with every NAIMA-certified facing. Wholesale pricing runs $1.13 to $1.23 per square foot, with VR-R Plus at the low end and WMP-50 with metalized polyester backing at the premium end.
R-25 Insulation Thickness and Composition
R-25 Nominal Thickness
R-25 fiberglass insulation has a nominal installed thickness of 8 inches. That dimension is engineered to fit 2x8 framing exactly. The full 8 inches is required to deliver rated R-25 performance. Compression to a shallower cavity loses thermal performance proportionally — R-25 compressed to 6.25 inches delivers roughly R-19, and compressed to 5.5 inches delivers roughly R-17.
R-25 Roll Dimensions
R-25 rolls ship in 4-foot, 5-foot, and 6-foot widths. Roll lengths run shorter than lower R-values (typically 16 to 40 feet) because of the thicker material profile.
Facing Options for R-25 Rolls
Every fiberglass insulation facing in the catalog is available in R-25 — vinyl-faced (VR-R Plus, WMP-10, WMP-30, WMP-50), foil-faced, black-faced, and unfaced.
Where R-25 Insulation Works Best
R-25 Insulation by IECC Climate Zone
R-25 is the IECC wall minimum across the northern half of the United States and the recommended ceiling/floor minimum in mixed and cold climates.
| IECC Zone | Example States | R-25 Used For |
|---|---|---|
| Zone 1-2 | FL, southern TX | Ceilings (rare, R-30 preferred) |
| Zone 3 | TX, GA, NC, AZ | Ceilings, floors |
| Zone 4 | VA, TN, KY, MO | Walls (recommended), ceilings |
| Zone 5 | CO, OH, IL, NY | Walls (minimum) |
| Zone 6 | MN, WI, MT, ME | Walls (minimum) |
| Zone 7 | Northern MN, WI, ME | Walls (minimum) |
| Zone 8 | Northern AK | Walls (R-30 preferred) |
For a complete R-value breakdown across all climate zones, see the R-Value Guide by Climate Zone.
R-25 Insulation Cost Per Square Foot
Wholesale R-25 fiberglass insulation pricing at Insulation Overstock runs $1.13 to $1.23 per square foot depending on facing. R-25 carries more material per square foot than R-19 (8 inches vs 6.25 inches of fiberglass), and the price reflects that.
- VR-R Plus (vinyl-reinforced PSP): $1.13 / sq ft
- WMP-10 / WMP-30 / WMP-50: $1.19 / sq ft
- Black-faced variants: $1.17 to $1.23 / sq ft
The Insulation Calculator returns total R-25 cost (material + freight + service fee) for any square footage and state. For larger orders, Bulk Insulation includes the $250 volume discount.
Available Facings for R-25 Rolls
R-25 is available with every facing in the catalog. Facing selection follows the same criteria as other R-values.
VR-R Plus (PSP) — Most Economical
VR-R Plus at $1.13 per square foot is the value choice for R-25. Suitable for most residential and light-commercial walls and ceilings.
WMP-10 (PSK-STD) — Standard Metal Building
WMP-10 with a 10-perm rating is the standard cold-climate metal building wall spec at R-25.
WMP-30 (PSK-HD) — Heavy-Duty, Humid Climates
WMP-30 with its 30-perm rating handles moisture better than WMP-10 — the right pick for humid Zone 5-6 climates.
WMP-50 (PSKP) — Premium Commercial
WMP-50 with metalized polyester backing is the spec for commercial warehouses, distribution centers, and aircraft hangars in cold climates.
Black-Faced Variants
Black-faced R-25 serves aesthetic and low-glare interior applications.
R-25 vs Other R-Values
| R-Value | Thickness | Best For | Wholesale Price/Sq Ft |
|---|---|---|---|
| R-13 | 3.625" | 2x4 walls, Zone 1-2 | $0.65 – $0.75 |
| R-19 | 6.25" | 2x6 walls, Zone 3-4 walls | $0.90 – $1.00 |
| R-25 | 8.0" | Zone 5+ walls, ceilings | $1.13 – $1.23 |
| R-30 | 9.5" | Ceilings, attics | $1.36 – $1.42 |
Choose R-25 when: framing is 2x8, building is in Climate Zone 5 or above, or you need a meaningful upgrade from R-19 for energy code or comfort.
Stay with R-19 when: framing is 2x6, climate is Zone 3 or 4, or budget is a hard constraint.
Upgrade to R-30 when: insulating ceilings or attics where deeper material fits, or building in Zone 7-8 where extra wall depth is justified.
R-25 Insulation FAQ
What is R-25 insulation?
R-25 insulation is fiberglass batt or roll insulation rated at R-25 thermal resistance per ASTM C518. It is the IECC wall minimum for Climate Zones 5 through 7 — most of the northern United States.
How thick is R-25 fiberglass insulation?
R-25 fiberglass insulation is 8 inches thick at nominal installed depth. The full thickness is required to deliver rated R-25 performance.
How much does R-25 insulation cost per square foot?
Wholesale R-25 fiberglass insulation runs $1.13 to $1.23 per square foot at Insulation Overstock. VR-R Plus is the lowest at $1.13; the WMP-10/30/50 line is $1.19; black-faced variants run $1.17 to $1.23.
Is R-25 enough for a cold-climate metal building?
R-25 meets the IECC wall minimum for metal buildings in Climate Zones 5, 6, and 7. Roof and ceiling applications in those zones should use R-30 or higher.
Can I install R-25 in a 2x6 wall?
No — R-25 needs 8 inches of cavity depth, and 2x6 framing offers only 5.5 inches. Compressing R-25 to fit a 2x6 reduces it to roughly R-19. For 2x6 framing, order R-19. For 2x8 framing, R-25 is dimensionally correct.
When should I choose R-25 over R-19?
Choose R-25 over R-19 when (a) framing is 2x8 (so it fits), (b) you are in IECC Climate Zone 5 or above (so it’s required), or (c) the building will be heated and cooled year-round and the added thermal performance pays back in energy savings (typically a 4-7 year payback).
Order R-25 Fiberglass Insulation
Wholesale R-25 with every facing available. Material, freight, and service fee itemized separately.
Price Calculator
Select your facing, R-value, square footage, and delivery state to see wholesale pricing instantly.
Add accessories and offer the Service Fee amount to complete order.