Internet #100322375

Model #193829

Store SKU #163524

Store SO SKU #621947

1-3/8 in. x 4 ft. x 8 ft. R-8.9 Foam Insulation

Questions & Answers (6)
  • Save money by lowering the cost of heating & cooling your home
  • Energy efficient alternative for non-insulating OSB or plywood
  • 1-3/8 in. x 4 ft. x 8 ft. R-8.9 Foam Insulation
  • See More Details

Product Overview

The TUFF-R R-8.9 1-3/8 in. x 4 ft. x 8 ft. Foam Insulation is Energy Star compliant and made with high-performance polyisocyanurate foam core for exceptional efficiency. It is lightweight and installs easily.

Info & Guides

You will need Adobe® Acrobat® Reader to view PDF documents. Download a free copy from the Adobe Web site.



Coverage Area (sq. ft.)
Product Depth (in.)
Product Height (in.)
Product Length (ft.)
8 ft
Product Thickness (in.)
1.375 in
Product Width (in.)
48 in


Compatible Install Surface
Faced or Unfaced
Insulation Features
Fire Block Rated,Formaldehyde Free,Soundproofing Insulation,Vapor Retardant
Insulation Location
2x4 Wall,2x6 Wall,Attic,Basement,Crawlspace,Exterior Sheathing,Exterior Wall Foundation
Insulation R-Value
Insulation Type
Foam Board Insulation
Number of Pieces
Product Weight (lb.)
Sheathing Size
8 ft. x 1.375 in. x 48 in.
Sheathing Type

Warranty / Certifications

Warranty Information
15 year limited thermal

Questions & Answers


can you paint this

Asked by will January 26, 2017

The facers of THERMAX™ Polyisocyanurate Insulation and TUFF-R™ Polyisocyanurate Insulation can be painted with an industrial-type latex acrylic paint. The facers must be clean and dry before applying paint. Oil-based paints can also be used. Painting Thermax /Tuff R foil Facers: FOIL: Treat surface and prime (optional but recommended). follow paint mfg directions for preferred surface preparation, or: 1.Clean off rolling oils. 2.Clean with mild detergent. 3.Rinse off well and dry before primer, 4.Get with paint rep - industrial type paint and primer for aluminum metal surface use Glidden, Sherwin Williams, or equivalent.

I don't understand the R rating . I see these at 8.9 or 3.3 . Compared to roll at lets say R30 , how does it measure up ? Thanks

Asked by Happy September 11, 2016

The R rating for these boards is related to their thickness. The 1 inch board is a little over R6, the 1/2 inch is about R3, etc. Different brands have different R per inch.

Can TUFF-R R-8.9 be used as heating/coolng metal duct insulation in basement?

Asked by Scott December 30, 2015

This insulation will work for basements and exterior sheathing.

Attic floor?

Asked by Randomuserid December 27, 2015

Dear RandomUserID: No foam board product is tough enough to be walked on. Foam board is also very flammable and must be covered by an approved "thermal barrier" in any occupied space or storage area, e.g. your attic. 3/4" plywood is accepted in most areas, but check with your local building inspector first. This would also give you a solid surface to walk on. A few more tips: (1) Seal all of the air leaks first: Leaking air and the 'stack effect' account for much of the energy lost into attics. Recessed lights are a #1 culprit, along the gap around an interior chimney. If you have recessed lights, cover them with Tenmat covers and seal the edges with DAP 230 to block leaks. See: Tenmat Model # FF130E Home Depot Internet # 204286308 Store SKU # 1000012747 If you have a chimney that runs through the attic, seal the gap around it with metal flashing and seal the edges with fireproof sealant to block air leaks. See: 3M Model # CP-25WB+ Home Depot Internet # 100166701 Store SKU # 163096 Seal other gaps and cracks, e.g. around plumbing vent pipes, with Great Stuff foam. (2) Roxul ComfortBoard is a good alternative to foam board. It provides R4 per inch, almost as much as foam board --- and is fire resistant. You could lay 1/2" plywood over it as a walking surface, with no worries about flammability, "thermal barriers" or your building inspector. See: Roxul Model # RXCB11224 Home Depot Internet # 206789748 Store SKU # 1001748089 (3) If you install foam board or ComfortBoard, seal all of the joints and edges carefully to block air leaks. The 'Windows and Doors' version of Great Stuff foam works well; the cured foam remains flexible to avoid cracks as things expand and contract. Do not install Great Stuff near anything that gets hot, however -- it is flammable, just like foam board. Use the 3M fire barrier sealant instead. I hope this is helpful. Mark

Can you sandwich two layers of this insulation in a 3 1/2 inch stud wall?

Asked by Mark December 10, 2015

Dear Mark: Yes. This is called the "cut and cobble" method, which takes more time than spray foam -- but you can do it yourself, and you can install it when the temps are too cold for spray foam. We recently completed the deep remodel of a home along the shore in Massachusetts, for example, and filled the walls with XPS foam board. A photo is attached. A couple of installation tips: (1) You don't need to carefully cut the pieces for a tight fit. Even a 1" gap is fine, because you will seal the edges with Great Stuff foam. (2) Carefully seal all of the seams and edges with the 'Windows and Doors' version of Great Stuff foam, to block air leaks. The 'Windows and Doors' version remains flexible after it cures, to avoid cracks as things expand and contract. Another option is Roxul ComfortBatt insulation, which provides R4 per inch -- almost as much as foam board, and it is not flammable. Seal the edges and joints, just like foam board. See: Roxul Model # RXSS31525, Home Depot Internet # 202531875 Store SKU # 982937 I hope this is helpful. Mark

Is this product fire rated if so approx burn hours

Asked by carlo October 31, 2015

Dear Carlo: No. In fact, Tuff-R foam board is very flammable like most foam products. It should never be installed near anything that gets hot, e.g. a furnace, chimney, exhaust duct, etc. It must be covered by a "thermal barrier" in occupied space, including a garage. A "thermal barrier" equals 1/2" drywall. A thermal barrier is also required in an attic or crawl / sub floor space if they are accessed for storage. If you need fire-rated insulation, Roxul rock wool is a good choice, with solid R4 / inch performance. Roxul is not flammable, and is also effective at deadening sound. See: Home Depot Model # RXSS31525 Internet # 202531875 Store SKU # 982937 Stiff board-like versions of Roxul are also available from your Home Depot's Pro Desk, e.g. Roxul ComfortBoard IS. I hope this is helpful. Mark

Customer Reviews

  • 5
    out of 1 reviews
  • 100% recommend this product
Filter by:
Showing 1-1 of 1 reviews
The best bang for your buck when you're building a Redbull Flugtag Glider!
This structural foam was a huge asset to my design of a glider for Redbull's Boston Flugtag Competition. Easy to set up on a CNC table, easy to mill, great for designing press fits over PVC pipes, it even provided unexpected rigidity to our 22' wing span. Follow our progress at Thanks for the wings, Home Depot!
by Flugtag90sNostalgia
Showing 1-1 of 1 reviews