The Owens Corning R-38 fiberglass batt is the clearest match for an attic with 2-by-12 framing, while the Knauf R-38 batt is listed for cathedral-style attic applications. The other options are reflective or high-temperature materials, not R-38 kraft-faced fiberglass batts, so they may suit specialized projects but should not be treated as direct substitutes. Compare the product dimensions and intended use with your framing before buying.
| Product | Best suited for | Important distinction |
|---|---|---|
| Owens Corning R-38 batt | Attics with 2-by-12 framing | Kraft-faced fiberglass batt |
| Knauf R-38 batt | Cathedral-style attic applications | 15-by-48-inch batt; listing does not specify facing |
| EcoFoil single bubble roll | Radiant-barrier projects | Not an R-38 batt |
| Ceramic fiber blanket | Specialized high-temperature uses | Not residential R-38 insulation |
| EcoFoil double bubble roll | Reflective insulation projects | Not an R-38 batt |
Owens Corning R-38 Kraft-Faced Fiberglass Batts
This listing describes eight bags covering 341 square feet of R-38 kraft-faced fiberglass batts, sized 16 by 48 inches. It is recommended for attic use and intended to fit between trusses in a 2-by-12 attic. Those details make it the most direct match here for buyers seeking R-38 kraft-faced insulation for that framing arrangement.
- Best for: Attic projects where the stated batt size and R-38 rating match the installation space.
- Why it was selected: The listing explicitly identifies R-38, kraft facing, fiberglass construction, and attic application.
- Limitation: The product is recommended for a specific attic arrangement; verify dimensions and installation requirements before ordering.
Knauf R-38 Kraft-Faced Attic Batts
The product name specifies R-38 fiberglass batts measuring 15 by 48 inches, with eight bags and 320 square feet listed. It describes the application as a 2-by-10 attic with high-density cathedral insulation. This makes it a potential choice when those dimensions and the cathedral-style application fit the project.
- Best for: Buyers considering R-38 batts for a cathedral-style attic and whose framing suits the listed size.
- Why it was selected: It is one of the two listings that explicitly identifies R-38 fiberglass batt insulation.
- Limitation: The supplied product details do not confirm kraft facing. Check the listing and packaging to verify facing type before purchase.
EcoFoil Single Bubble Reflective Roll
This 48-inch-by-125-foot roll covers 500 square feet and is described as 3.175 mm thick. The listing says it reflects 96% of radiant heat. It is a radiant barrier product, not a kraft-faced fiberglass batt or an R-38-rated product.
- Best for: Buyers seeking a reflective radiant barrier for a project designed around that material.
- Why it was selected: It is a listed insulation-related option, but its function differs from the requested batt.
- Limitation: Do not use the stated radiant-heat reflection as an R-value equivalent to R-38.
Aluminum-Faced Ceramic Fiber Blanket
This blanket measures one-half inch by 24 inches by 75 inches and is listed as rated to 2400°F. Its ceramic-fiber construction and high-temperature rating distinguish it from residential R-38 fiberglass batts.
- Best for: Specialized applications where the listed high-temperature material is appropriate.
- Why it was selected: It is an insulation blanket among the supplied products, though it does not match the residential R-38 search intent.
- Limitation: The product listing does not identify it as R-38 or as attic batt insulation.
EcoFoil Double Bubble Reflective Roll
This foil roll measures 48 inches by 75 feet, covers 300 square feet, and is listed as 6.35 mm thick. Its description identifies it as a double-bubble radiant barrier for cold and warm climates. It is a different product category from kraft-faced R-38 batt insulation.
- Best for: A project specifically calling for double-bubble reflective foil material.
- Why it was selected: It offers a reflective insulation alternative from the supplied options.
- Limitation: The provided details do not state an R-38 rating or a fiberglass batt format.
Buying Guide: Choosing R-38 Kraft-Faced Insulation
Does R-38 describe the product you need?
R-38 is the stated thermal-resistance rating on the two fiberglass batt listings. The reflective rolls and ceramic fiber blanket have different listed functions and specifications. Do not compare their radiant-heat claims or temperature rating directly with an R-value. If the project requires R-38 batts, prioritize a listing that expressly states R-38.
Which batt dimensions fit the framing?
Compare the listed batt width and length with the framing space and intended installation area. The Owens Corning option is 16 by 48 inches and is described for a 2-by-12 attic. The Knauf listing gives 15 by 48 inches and mentions a 2-by-10 attic and cathedral application. Confirm the actual space and product packaging before purchase.
Does the facing type matter?
Kraft facing is a specific product detail, not a synonym for any foil-faced or reflective material. Owens Corning is explicitly identified as kraft faced. The supplied Knauf details do not confirm its facing, so verify that information if kraft facing is required. Follow applicable installation instructions and local building requirements.
How much coverage should you plan for?
Use the listed coverage to estimate the required quantity, then account for the actual area and layout. The Owens Corning listing states 341 square feet across eight bags; Knauf states 320 square feet across eight bags. Coverage alone does not establish that a product fits a particular framing system.
Frequently Asked Questions
Which listed product is explicitly kraft faced and R-38?
The Owens Corning listing explicitly describes R-38 kraft-faced fiberglass batts.
Is the Knauf product confirmed as kraft faced?
The supplied details identify it as R-38 fiberglass batt insulation but do not confirm the facing type. Check the product listing or packaging.
Can reflective foil replace R-38 fiberglass batts?
The supplied foil-roll descriptions do not provide an R-38 rating. Treat them as radiant-barrier products, not direct R-38 batt substitutes.
What does “faced” mean in kraft-faced insulation?
It means the batt has a kraft-paper facing. Verify the product description and follow the installation guidance for the specific insulation and building assembly.
Should insulation be installed tightly against attic ventilation?
Follow the product’s installation instructions and preserve required ventilation clearances. The Owens Corning listing specifically advises properly vented air space when using unfaced insulation.