105 in. length reduces vertical joints on taller stud layouts
Key features
15 in. width for 16 in. o.c. nominal 2×6 stud bays
Unfaced PINK Next Gen for designer-controlled vapor detailing
Technical specifications
| R-Value | 21.0 |
|---|---|
| Thickness | 5.5 in |
| Width | 15.0 in |
| Length | 105.0 in |
| Coverage | 87.5 sq ft/pack |
| Material | Fiberglass (PINK Next Gen), unfaced |
| Fire rating | ASTM C665; unfaced glass fibers classified noncombustible per ASTM E136 in manufacturer documentation. Unfaced PINK Next Gen acceptable ICC types I–V per OC literature. |
| Sound rating | Cavity-fill fiberglass improves typical wall STC versus an empty cavity; assembly STC remains system-dependent. |
| Density | Light-density flexible batt per ASTM C665 manufacturer listings; see TDS for product-specific values. |
| Thermal conductivity | Nominal R-21 at full labeled thickness; see manufacturer TDS (ASTM C518) for tested conductivity. |
| Framing width | 15 in. width for 16 in. on-center stud spacing in nominal 2×6 walls |
| Construction type | Wood-frame and light-gauge metal-frame cavity construction |
| Application area | Wood- and metal-framed walls, floors, roof/ceilings; interior side of basement and unvented crawlspace walls per code |
Product details
About 87.5 square feet per package (IDI-listed coverage). Primary use: nominal 2×6 exterior or partition walls on 16 in. on-center framing where stud packs run 105 in. or taller and the specifier wants unfaced R-21 cavity fill to reduce mid-height butt joints compared with shorter batts.
K27 packages PINK Next Gen fiberglass at 5.5 in. labeled thickness for R-21 performance, 15 in. width for the common 14-1/2 in. clear bay, and 105 in. length for production builders stacking nine- and ten-foot first-floor walls. Unfacing keeps Class I vapor-retarder decisions with the designer—pair with smart membranes, exterior foam, or climate-specific interior strategies as the drawings require.
Execution still demands continuous air barriers at rim and penetrations, honest thickness at corners, and careful relief at outlets and pipes so you do not pack dense wads that delete R-value.
Manufactured to ASTM C665; unfaced glass fiber is noncombustible per ASTM E136 in manufacturer documentation with ICC types I–V language for unfaced PINK Next Gen. GREENGUARD certification with formaldehyde-free validation and a UL Environment EPD support typical submittals. Use the linked TDS for tested properties and package weights.
One-hundred-five-inch batts change vertical joint math on tall gable and stair walls compared with 93 in. stock; still measure actual stud lengths after plates before promising one-piece coverage.
Unfaced tall-wall batts are often paired with separate vapor retarders or exterior foam; document those layers in the same submittal package as the cavity insulation SKU.
Next Gen handling helps when crews plan vertical cuts at openings, but QA disputes still hinge on the stamped bag label—photo master packs when plan dimensions and field plates disagree by an inch or two.
Submittal discipline: keep the distributor-listed dimensions (5.5 in. × 15.0 in. × 105.0 in.) and about 87.5 square feet per package attached to the same SKU on purchase orders, delivery tickets, and photos for QA. Authoritative tested language and code-oriented statements belong in the current manufacturer technical data sheet at https://www.idi-insulation.com/media/pdfresources/1004460_data_sheet.pdf.
Documents & certifications
Technical data sheet
Manufacturer-tested R-value, coverage, fire notes, and handling—use for submittals, RFIs, and field QA.
Download PDF (opens in new tab)Certifications & compliance
GREENGUARD (formaldehyde-free validated), UL Environment EPD, California Title 24 Article 3 insulating materials
Frequently asked questions
K27 versus kraft-faced BF65 at the same module?
K27 versus kraft-faced BF65 at the same module?
BF65 adds kraft facing for Class I vapor-retarder detailing when your assembly allows it. K27 is unfaced—use it when vapor control is specified on another layer.
Will 105 in. always reach plate to plate?
Will 105 in. always reach plate to plate?
Measure actual stud lengths after plates, platforms, and slab tolerance. Tall packs still need field cuts at openings and stairs.
How many bags for my wall takeoff?
How many bags for my wall takeoff?
Divide net insulated wall area by about 87.5 square feet per bag and add a waste factor for openings and cuts.
Can I compress K27 behind pipes?
Can I compress K27 behind pipes?
Compression reduces effective R-value. Split batts or knife-cut relief so the insulation recovers to labeled thickness.