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FOAMULAR 150 1 in. x 4 ft. x 8 ft. R-5 Scored Square Edge Rigid Foam Board Insulation Sheathing

  • Saves energy and resists moisture with limited lifetime warranty
  • Scored edge easily snaps into smaller boards for best fit
  • Strong, lightweight pink foam panels don't require special tools
  • See More Details

Product Overview

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.

icon for moisture resistance

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 line of products - choose the strength you need, from 15 to 60 PSI and exceptional moisture resistance. Products provide superior insulating properties; R-value (5- in. of product thickness). The products are easy to handle, score, cut and install and no special tools are needed. Products can be used on wood, steel framing or concrete walls. Owens Corning provides home builders and home buyers with a number of insulation solutions to meet their needs.
  • Closed cell product is equal to moisture resistance
  • Lifetime limited warranty
  • Wide choice of sizes, thicknesses and edges
  • Retains R-value even after exposure to moisture and freeze thaw cycling
  • 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.
  • If being used in an interior construction application, painting the FOAMULAR is not recommended as FOAMULAR cannot be left exposed and will need to be covered by a 15 minute thermal barrier such as drywall.
  • If being used for crafts, acrylic or latex based paints can be used with FOAMULAR products.
  • If 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 two 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’ sheet, break it in two and have two, 2’ wide sheets (middle score), or you can break it into three 16” wide pieces by snapping at the left and right score.
  • Click here to shop Loctite foamboard adhesive

Info & Guides

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Compare Similar Foam Board Insulation

FP Ultra Lite 1 in. x 2 ft. x 4 ft. Stucco Grey Foundation Panel24 in. x 1 in. x 48 in. R5 Radiant Acoustic Insulation Kit - STC 19 (5-Piece)
current product
FOAMULAR 150 1 in. x 4 ft. x 8 ft. R-5 Scored Square Edge Rigid Foam Board Insulation Sheathing
BrandSTYRO IndustriesSilveRboardOwens Corning
NameFP Ultra Lite 1 in. x 2 ft. x 4 ft. Stucco Grey Foundation Panel24 in. x 1 in. x 48 in. R5 Radiant Acoustic Insulation Kit - STC 19 (5-Piece)FOAMULAR 150 1 in. x 4 ft. x 8 ft. R-5 Scored Square Edge Rigid Foam Board Insulation Sheathing
Product Thickness (in.)11 in1 in
Insulation LocationExterior Wall Foundation2x4 Wall,2x6 Wall,2x8 Wall,Attic,Basement,Ceiling Insulation,Exterior Sheathing,Garage,Metal Building,Re-SidingExterior Wall
Insulation R-ValueR5R5R5
Sheathing TypeXPSEPSXPS
Insulation FeaturesMold Resistant,Paintable,Water ResistantFormaldehyde Free,Vapor RetardantFormaldehyde Free
Compatible Install SurfaceCement,Concrete,Existing InsulationCement,Concrete,Existing Drywall,Existing Insulation,PlywoodPlywood,Wood
Product Length (ft.)22 ft8 ft
Faced or UnfacedFacedFacedUnfaced
Product Width (in.)4848 in48 in
View ProductView ProductView Product



Coverage Area (sq. ft.)
Product Length (ft.)
8 ft
Product Thickness (in.)
1 in
Product Width (in.)
48 in


Compatible Install Surface
Faced or Unfaced
Insulation Features
Formaldehyde Free
Insulation Location
Exterior Wall
Insulation R-Value
Insulation Type
Foam Board Insulation
Number of Pieces
Pack Size
Product Weight (lb.)
0.131 lb
Sheathing Size
8 ft. x 1 in. x 48 in.
Sheathing Type

Warranty / Certifications

Warranty Information
Limited Lifetime

Questions & Answers


How much insulation would I need to cover a 12x24 building

Asked by Dag May 5, 2021

Hello Dag, each 4x8 board of Foamular 150 covers 32 square feet. Depending on the height of the building and any cuts that need to be made may vary the number of boards needed. Thank you for your inquiry!

Where is the scoring? What are the measurements for the scored lines?

Asked by BTS May 2, 2021

Hello BTS, Owens Corning Scored Squared Edge products have 3 score marks at 16", 24" and 32" across the board. This allows the board to be easily snapped into 3 16" pieces or 2 24" pieces. Thank you for your inquiry!

If I cut the board with a sharp blade knife will the edge be smooth or will I end up with a bunch...

Asked by Rick April 26, 2021

Hello Rick, You should be able to achieve a clean edge if you score or cut the board with a sharp utility knife then snap the edge. Thank you for your inquiry!

is this product ok for insulating pipes underground

Asked by bruce April 20, 2021

Hello bruce, While Foamular can be used below grade, insulating pipes underground requires consideration of many factors. Please contact Owens Corning at 1-800-Get-Pink (438-7465) to get additional information needed to successfully perform this application. Thank you for your inquiry!

Are these panels termite resistant? We had to tear out the knee wall paneling, drywall, 1" Styrof...

Asked by MrD March 6, 2021

Hi Mr. D. Termites eat products that contain cellulose. Pure polystyrene products have no cellulose, but some companies add it to their formulation. Regardless, termites can eat through either, especially if it's between them and another source of food--damp, soft woods. This is a good product for adding an insulative barrier between your concrete foundation and interior finished wall, but you've got to stop the water/moisture intrusion in order to permanently eliminate termites.

Can I use this to insulate my well house on the inside?

Asked by Mpic February 23, 2021

Hello Mpic, Foamular can be used in this application. With your application being an out building/agricultural building it does not require Foamular to be covered by a 15 minute thermal barrier. Thank you for your inquiry!

Can this be used in a crawlspace to replace insulation removed for plumbing update? If not what product is recommended?

Asked by Fergmgb January 24, 2021

Hello Fergmgb, Owens Corning Foamular products are combustible and in most cases needs to be covered by a 15-minute thermal barrier such as 1/2" drywall. There are some cases in crawlspaces where it can be left alone. Please see section 6.5 of the Evaluation Report (link below) to determine if your crawlspace meets the criteria to leave Foamular exposed. Thank you for your inquiry!

I want to put this on my concrete walls in my basement. Can I leave them exposed or do I have to...

Asked by Channa January 14, 2021

Hello Channa, Owens Corning Foamular is a combustible product and cannot be left exposed. It needs to be covered by a 15 minute thermal barrier such as 1/2" drywall. Thank you for your inquiry!

I would like to attach some kind of rigid foam insulation to the inside of my white decorative vi...

Asked by JC January 13, 2021

Dear JC: Rather than try to create an insulated 'skirt' for your home, you should insulate the floor above the crawlspace -- if it has enough height to be accessible. In your climate, I would start by filling the joist bays with rock wool. Use Simpson insulation wire to hold the rock wool batts up in the joist bays. Then screw 1" Foamular panels to the bottom of the joists. Carefully seal all of the joints and perimeter, to block air leaks. DAP 230 and HVAC mastic work well for joints and small gaps. Use the 'Window and Door' version of Great Stuff spray foam for the perimeter and larger gaps. Buy the $50 Great Stuff Pro gun for this project; it is much easier to use for the number of liner feet you will cover. If the crawlspace is not accessible, using foam board as a 'skirt' is possible, although it is difficult to air-seal (and maintain the air-seal) on all of the joints and edges. Use the same products noted above, but tape the joints between panels with 3M flashing tape, sold in Home Depot under the Anderson brand name in the window and door section of the store. This aggressively sticky tape will hold the panels together. Be sure to paint over it, however, because the tape cannot be left exposed permanently to sunlight. This flashing tape can also be used along the top edge. Also bury the bottom of the foam board a couple of inches into the soil, to seal that end and help to keep the panels in place. Foam board is flammable. If you are concerned about this, there is one option: Rockwool Rockboard, which is a board-like product made from rock wool -- which is fire resistant. You can order it via your Home Depot's Customer Service or Pro Desk. Ask for Rockboard 60 with foil facing. They will deliver to your Home Depot for free -- or to your home for a small fee. (Lookup Rockboard 60 on the Web for a complete description.) Many customers are not aware that Home Depot carries a much larger array of building materials than what is displayed on store shelves. This is one example. Use the same 3M / Anderson tape to air seal the joints and fasten the panels together. I hope this is helpful. Mark

When will the new NGX version of this be available?

Asked by NeedsaHaircut January 1, 2021

Hello NeedsaHaircut, Owens Corning Foamular NGX became available January 1, 2021.It will be a standard product in the regulated states. Unregulated states can order NGX if they want, however depending on the product it could be a Made To Order and have extended lead times. Below is a link to our website showing the regulated states. https://www.owenscorning.com/en-us/insulation/commercial/foamular-ngx Thank you for your inquiry!

FOAMULAR 150 1 in. x 4 ft. x 8 ft. R-5 Scored Square Edge Rigid Foam Board Insulation Sheathing - page 2

Customer Reviews

  • 4.8
    out of 409 reviews
  • 98% recommend this product
Filter by:
Showing 1-10 of 409 reviews
I had to use this product on an attic re-insultation project that required a new engineered appro...
I had to use this product on an attic re-insultation project that required a new engineered approach to the solution. The product was a success in its application. It is super easy to use and cut or trim in place, especially for tight quarters. The house was a 1930s cape cod with shallow 2x4 ceiling joists. The detail required building up the 2x4 ceiling joists to provide a cavity depth that accepts 2 layers of R-19 or one layer of R-38, then cap the enitre area of rolled insultation with R-10 rigid foam to provide a minimum R-rating of 48. Additionally, capping the entire area with rigid foam enabled a platform working surface for future attic accessibility and wiring/ventilation/interior roof maintenance. Overall, very impressed with the product.
by AtticInsulationProject
Used to make a quilters station on a wall
Used to make a quilters station on a wall
by ou812
Product does what I needed to. Used as full sheet...
Product does what I needed to. Used as full sheet to insulate along my basement walls and then frame next to it. This helped reduced install time so I wasn’t cutting them to fit perfectly in between studs. You can feel the difference in temperature and the price was better on my wallet too
by Luke
Did not work as advertised
I put up Foamular sheets under polycarbonate roofing panels in my gazebo. Figured since the sheets were advertised at able to withstand temperatures of 165 Deg F, they would be fine. Not so. The sheets just buckled and warped and stuck to the polycarbonate. They also shrank in thickness from 1in down to less than 1/2in. The sheets became very brittle and just cracked. The temperature was over 100 Deg F, maybe 110 Deg F, but nowhere near 165 Deg F. Looks like they do not handle being exposed to sunlight - even if under polycarbonate sheets. Have to peel them off - they are stuck to the polycarbonate - in pieces. Also the polycarbonate sheets are ruined. Have to figure out how to maybe sand down the stuck on bits of Foamular.
by KP
Response from OwensCorningJun 3, 2020
Hello KP, Thanks for sharing your experience. It helped us learn a little bit more about how customers use our products. Please feel free to contact us at 1-800-GET-PINK so we can address your concerns directly. Thank you for your review.

Thank you!
Owens Corning
5 people found this helpful
I used this to insulate my garage door from the heat of the morning sun. It did that, plus much m...
I used this to insulate my garage door from the heat of the morning sun. It did that, plus much more. The sound insulation is better than anything I could have expected. I live on a busy four lane road and the difference is DRAMATIC! I can still hear the road noise, but not much. Also I have a neighbor that likes to play load music while working on their car. So loud that the garage door would literally rattle, that is no more. Oh yeah, the garage doesn't heat up as much either. Other things worth mentioning. The sheets were perforated every 12 or 24 inches which saved my life once I realized it was NOT going to fit in my Honda Pilot. I was able to break it down in the parking lot. When I was cutting it to size, it was easy to mark with a pencil and then cut with a utility knife. I found that if I cut firmly and confidently I could cut the sheet and then snap it apart without the need for a second pass. It breaks super cleanly.
11 people found this helpful
Easy to use and insulated my basement ...
Easy to use and insulated my basement
by Adam
1 person found this helpful
This was a life saver this winter keeping a hermit...
This was a life saver this winter keeping a hermit crab tank at the proper temperature.
by Claudia
We use these boards to make light weight set for stage performances. They cut and paint easily an...
We use these boards to make light weight set for stage performances. They cut and paint easily and glue together using the recommended glue and wood skewers to hold them together. The 4 star rating rather than a 5 star was because the shelf was not fully stocked and I had to take a couple culls!
by HomeDepotCustomer
6 people found this helpful
I used these sheets to build foam blocks as a Christmas present. I cut them on my table saw at a ...
I used these sheets to build foam blocks as a Christmas present. I cut them on my table saw at a 45 degree angle. They cut very smoothly and the end product was loads of fun on Christmas day and New Year's Eve. I glued the pieces with Gorilla glue and taped them with metal heat duct tape.
by AverageDude
1 person found this helpful
Used it to inulate my garage door panels .... easy cut with a skillsaw
Used it to inulate my garage door panels .... easy cut with a skillsaw
by Gordman
8 people found this helpful
Showing 1-10 of 409 reviews