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FOAMULAR 250 1 in. x 2 ft. x 8 ft. R-5 Tongue and Groove Rigid Foam Board Insulation Sheathing

  • Saves energy and resists moisture with limited lifetime warranty
  • Tongue and groove board edge to reduce gaps and eliminate drafts
  • Strong, lightweight pink foam panels don't require special tools
  • View More Details
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Product Details

Home with pink outline and Owens Corning logo

A Home is a Fortress

It keeps comfort and safety in - and the other stuff out. Help create the year-round protection every home deserves with proven solutions that work where and when you need them most.

close up of Owens Corning Foamular with water beads

Owens Corning FOAMULAR XPS

FOAMULAR is a rigid insulation board made of extruded polystyrene. XPS for short. Compared to EPS products, FOAMULAR XPS has 25% more insulating power and is 10 times more water resistant.

Cutaway image of a house with Foamular installed in different locations

Choose Above- and Below-Grade Protection

FOAMULAR provides continuous insulating power around the entire home from the foundation to the roofline and all kinds of spaces in between.

man installing fiberglas insulation  over Foamular

Insulating Basement Walls

FOAMULAR is the easy-to-install insulating solution for basement walls. Get added comfort with PINK Fiberglas insulation and finish with drywall board.

man installing Foamular in exterior foundation application

Insulating Foundation Walls

FOAMULAR is ideal for insulating exterior foundation walls. Extremely durable, it can withstand up to 15-25 psi and resists common acid soils and decay.

man installing siding over Foamular

Insulating Under Exterior Siding

FOAMULAR provides a higher R-value per inch than other materials commonly used for exterior wall sheathing.

man installing Foamular fanfold insulation

Also Available in Fanfold

FOAMULAR Fanfold is generally intended for use as a backer board for residing applications and comes in 50-foot sections for a faster install.

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Superior Moisture Resistance

Virtually impervious to moisture. FOAMULAR has up to 10X more resistance to water than EPS insulation.

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Durable, Yet Flexible

A wide range of compressive strengths –up to 100 psi – to handle heavy loads.

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Easy to Cut, Form and Fit

Easy to handle, score, cut and install; no special tools needed.

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Outstanding Insulating Properties

High, stable R-value (5 per inch of product thickness) - more than wood fiber, plywood or 1/2” gypsum board.

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Foamular is certified to meet indoor air quality standards under the stringent GREENGUARD Gold Certification Program.

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Lifetime Guarantee

The only XPS with a limited lifetime warranty that guarantees a minimum 90% of R-value for the life of the product.

FOAMULAR Extruded Polystyrene (XPS) Rigid Foam Insulation offers a comprehensive product line of insulation boards in a wide choice of sizes, thicknesses and edges with a Lifetime Limited Warranty for the life of the home or building. Foam insulation boards are easy to handle, score, cut and install & no special tools are needed. Rigid foam insulation products can be used on wood, steel framing or concrete walls. FOAMULAR XPS resists moisture and retains R-value even after exposure to standing water and wet soil. Only XPS foam to be GREENGUARD Gold Certified and the first XPS foam certified by Scientific Certification Systems (SCS) to contain a minimum of 20% recycled content.
  • Dimensions: 1 in. x 2 ft. x 8 ft.
  • Insulation Application: exterior foundation walls, underslab, foundations and crawlspaces
  • Insulation foam boards are highly moisture-resistant and helps to block mildew
  • Rigid foam insulation has a higher R-value than wood fiber, plywood or 1/2 in. gypsum board products
  • Click here to shop Loctite foamboard adhesive
  • Foamular 150 and 250 are available in various thicknesses and R-values, the difference is the compressive strength, foamular 150 has a compressive strength of 15 psi and foamular 250 is 25 psi
  • Foamular is not rated for STC (sound transmission) and does not have any soundproofing properties. Owens Corning fiberglass batts and rolls are great options for acoustic applications
  • When using foamular or any low perm insulation, always verify the moisture vapor flow and dew point characteristics of the wall system, please check your local building codes for vapor retarder/barrier information
  • Being used in an interior construction application, painting the fo is not recommended as foamular cannot be left exposed and will need to be covered by a 15 minute thermal barrier such as drywall
  • Being used for crafts, acrylic or latex based paints can be used with foamular products
  • You're looking to insulate your garage door, owens corning garage door insulation Kit is an easy, fast and affordable way to keep your garage warm in winter and cool in the summer
  • If you're looking to ventilate your attic rafters, owens corning Raft-R-Mate is a XPS foam vent designed to assure unrestricted airflow from the soffit to the ridge vent
  • Foamular is available in 2 edge configurations
  • Square edge - designed to fit flush next to adjoining boards
  • Scored square edge - comes with 3 factory scores, so that you can take a 4 ft. sheet, break it in 2 and have two, 2 ft.wide sheets (middle score) or you can break it into three 16 in. wide pieces by snapping at the left and right score
  • Click here to shop Owens Corning Foam Board Insulation styles
  • Click here to shop loctite foamboard adhesive
  • Click here to learn more about Eco Options and Energy Efficiency
  • Click here to learn more about Insulation R-Values
  • Return Policy



Questions & Answers

Q:Price of the one inch tongue and groove 8x2 sheet and four by eight sheets
by|Aug 26, 2023
1 Answer
Answer This Question

A:  Hello Kathleen, for pricing information please contact your local Home Depot. Thank you for your inquiry!

by|Aug 29, 2023
    Q:Is the 1”x2’x8’ tongue and groove foam board still avaible
    by|Mar 16, 2020
    1 Answer
    Answer This Question

    A:  Hello Ron - Please contact a representative at your local Home Depot ProDesk and they will be happy to assist you. Or you can call 1-800-HOME-DEPOT (1-800-466-3337) and someone will be happy to assist you as well. Thank you for your inquiry!

    by|Mar 16, 2020
      Q:Since FOAMULAR 250 is paintable, what is the proper paint type?
      by|Nov 25, 2019
      2 Answers
      Answer This Question

      A:  Hello Doug, If being used for crafts, oil-based and latex paints can be used with Foamular products. If being used in an interior construction application, painting the Foamular is not recommended as it will need to be covered by a 15 minute thermal barrier such as drywall. Thank you for your inquiry!

      by|Nov 25, 2019

        A:  Dear Doug: You can paint Foamular with standard acrylic primer and paint. That said, I hope you are aware that Foamular and similar foam board products are flammable and emit toxic gas when they burn. They must be covered by an approved 'thermal barrier' in any living space, garage, basement or attic storage area. The standard is 1/2" drywall . So for residential and commercial applications, foam board cannot be simply installed and painted. I hope this is helpful, Mark

        by|Apr 21, 2023
        1 found this answer helpful
        Q:Can i use a contact cement to glue this to metal?
        by|May 4, 2016
        1 Answer
        Answer This Question

        A:  Dear Van12: Yes. If you are planning to glue sheets of Foamular to a metal roof, that is a good application. One important caveat: like all foam insulation products, Foamular is very flammable and must be covered by a 'thermal barrier' (e.g. 1/2" dry wall) in any occupied building, basement, storage area, barn, etc. Intumescent paint is also an option, if your building inspector approves. We recently used Foamular 250 to insulate a major remodel in Massachusetts. All of the stud bays on the exterior walls were filled with Foamular and air-selaed with Great Stuff. The exterior was also wrapped with 2" of Foamular to block thermal bridging and improve insulation performance. 1" x 3" strapping was added on top, to easily attach the new siding. A couple of photos are attached. A non-flammable alternative, Roxul ComfortBoard, is now carried by most Home Depots. Made from rock wool, it provides R4 insulation performance per inch -- almost as high as foam board. No thermal barrier is required. See: Roxul Model # RXCB11224, Home Depot Internet # 206789748 Store SKU # 1001748089. I hope this is helpful. Mark

        by|May 3, 2023
        Showing 1-4 of 20

        Customer Reviews

        4.8 out of 5
        • 4.8
          out of 7 reviews
        • 100% recommend this product
        Filter by:
        Showing 1-7 of 7 reviews
        Very Satisfied
        Very Easy to install. will definitely buy this product again. we noticed a difference immedately after installing this in our basement.
        • DIY
        • Recommended
        5 found this review helpful
        Easy to use - works like a charm
        I recently used this to insulate the interior of my basement. It went up easily. In fact, it went up so quickly that insulating the basement was the most satisfying part of the entire basement finishing project. When needed I trimmed with a utility knife before using adhesive to stick these to the cinder block walls. I did not think of my basement as cold before this work, but I noticed a difference immediately - it is now the coziest room in the house. I would use this stuff again in a heartbeat. I spent a great deal of time reviewing the various insulation options before choosing foamular XPS. So glad I made this choice. The combination of ease of use, effective insulation, and ability to use below grade made this exactly what I needed.
        • DIY
        • Recommended
        1 found this review helpful
        I needed to fill in a misplaced window. I used this product to insulate the outside. Since the outside of the project was inside my garage I asked the employee that was helping me if this product was paintable. I was told it was and used a waterproof primer/paint spray. It was melting the board. It wasn't major but I would recomend some sort of over boarding or paneling if you want to paint for weatherproofing. In all I liked the product's ease of instillation, and was impressed at the insulationing effect for my kitchen.
        • DIY
        • Recommended
        1 found this review helpful
        Dood Stuff
        Does the job. I installed it on the underground walls of the basement. This winter my laser temperature gun showed room temperature on the foam and 5 to 10 degrees lower on adjacent uninsulated wall. I used 2 inch foam board on above ground walls with similar results.
        • DIY
        • Verified Purchase
        • Recommended
        Expensive but efficient
        I used this to muffle the sound of an inline fan on a false wall and it worked great. it's very easy to work with which is why i pay for it but on the expensive side for insulation.
        • DIY
        • Recommended
        3 found this review helpful
        this product is awsome
        Do you want to save energy, this will do it. Its tough and the r value is very good compared to the other products and easy to install. Thanks home depo for another great item
          • Recommended
          11 found this review helpful
          It may be sold as insulation, but it's the ONLY sheet foam product you want to use for hobby projects! Lightweight and quite strong, it cuts and shapes easily - and without those annoying "sticky balls" that get all over everything when you use "white styrofoam" which is easier to find. This pink foam sheet is the first choice of serious model railroaders and model airplane builders, and even sculptors who do lightweight sculptures!
          • DIY
          • Recommended
          13 found this review helpful
          Showing 1-7 of 7 reviews