Internet #100320301

Model #21UM

Store SKU #409692

FOAMULAR 1/4 in. x 4 ft. x 50 ft. R-1 Fanfold Rigid Foam Board Insulation Sheathing

  • Saves energy and resists moisture with limited lifetime warranty
  • Reduce gaps and eliminate drafts with film faced uniform surface
  • Folded hinge at 24" intervals to ease application at job site
  • See More Details

Product Overview

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Strong And Durable

FOAMULAR® XPS is stronger and more flexible than EPS.

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Resistant To Mold & Moisture

FOAMULAR® XPS has up to 13x better water resistance than EPS.

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Easy To Cut, Form & Fit

FOAMULAR® XPS cuts cleaner and doesn't break apart or crumble like EPS.

man installing Foamular in a basement

Insulating Basement Walls

Without adequate insulation, it’s difficult to heat and air-condition a basement room effectively. Owens Corning® FOAMULAR® is the easy-to-install, efficient solution for insulating basement walls.

Man preparing to install Foamular in a crawlspace

Insulating Crawlspace Walls

Because heat m.igrates to cold through the bottom of the house, an uninsulated crawlspace means you’ll use more energy to heat your home during winter and to cool it in summer. Insulate your crawlspace with Owens Corning® FOAMULAR®.

Man installing Foamular in a garage ceiling

Insulating Garage Or Bonus Room

Use Owens Corning® FOAMULAR® to insulate your garage ceiling / bonus room floor to effectively condition the space.

Man installing Foamluar on an exterior wall surface

Insulating Exterior Facing Wall Cavity

Owens Corning® FOAMULAR® provides a higher R-value per inch than other materials commonly used for wall cavity insulation.

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Warranty

Warranted to retain at least 90% of its advertised R-value over the lifetime of the product - Industry leading warranty across all thicknesses and compressive strengths.

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R-Value

The R-value for insulation measures how well insulation materials can resist heat - the higher the R-value, the greater the insulation performance. FOAMULAR is best ­ at maintaining R-value where moisture is present.

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Third Party Certifications

FOAMULAR is certified for Recycled Content and Air Quality by esteemed third party organizations.

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Make More Possible

Owens Corning is a global leader in engineered materials for roofing, insulation and composites.

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World Class Sustainability

For us, sustainability is about meeting the needs of the present while leaving the world a better place for the future.

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OC Gives Back

We make a difference by empowering people and the communities in which we live and work.

FOAMULAR Extruded Polystyrene (XPS) Rigid Foam Insulation offers a comprehensive line of products in a wide choice of sizes, thicknesses and edges with a lifetime limited warranty for the life of the home or building. 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. 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: 1/4 in. x 4 ft. x 50 ft.
  • Application: backer board for under new or replacement siding
  • Closed cell lightweight foam board
  • Thermal performance of R1
  • 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
  • Click here to learn more about Eco Options and Energy Efficiency

Info & Guides

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

Compare Similar Foam Board Insulation

24 in. x 1 in. x 48 in. R5 Radiant Acoustic Insulation Kit - STC 19 (5-Piece)Multipurpose High Density Insulation Kit R10 2-3/8 in. x 24 in. x 48 in. (5-Panels)19 in. x 150 ft. Sticky Mesh Heavy Duty
current product
FOAMULAR 1/4 in. x 4 ft. x 50 ft. R-1 Fanfold Rigid Foam Board Insulation Sheathing
BrandSilveRboardAmvicSTYRO IndustriesOwens Corning
Name24 in. x 1 in. x 48 in. R5 Radiant Acoustic Insulation Kit - STC 19 (5-Piece)Multipurpose High Density Insulation Kit R10 2-3/8 in. x 24 in. x 48 in. (5-Panels)19 in. x 150 ft. Sticky Mesh Heavy DutyFOAMULAR 1/4 in. x 4 ft. x 50 ft. R-1 Fanfold Rigid Foam Board Insulation Sheathing
Price
$2651
/package
$5608
$8135
Ratings
(186)
(104)
(47)
(88)
Product Thickness (in.)1 in2.375 in0.0750.25 in
Insulation Location2x4 Wall,2x6 Wall,2x8 Wall,Attic,Basement,Ceiling Insulation,Exterior Sheathing,Garage,Metal Building,Re-SidingBasement,Exterior Wall Foundation,Floor,Garage,Under SlabBasement,Ceiling Insulation,Exterior Sheathing,Exterior Wall,Exterior Wall Foundation,Interior Ceiling,Interior Wall,Wood SidingRe-Siding
Insulation R-ValueR5R10 R1
Sheathing TypeEPSEPSEPSXPS
Insulation FeaturesFormaldehyde Free,Vapor RetardantFormaldehyde Free,Vapor RetardantMold ResistantFormaldehyde Free
Compatible Install SurfaceCement,Concrete,Existing Drywall,Existing Insulation,PlywoodCement,Concrete,PlywoodCement,Concrete,Existing Drywall,Existing Insulation,Fiberglass,Plywood,WoodConcrete,Plywood,Wood
Product Length (ft.)10 ft10 ft15050 ft
Product Width (in.)48 in48 in1948 in
Faced or UnfacedFacedUnfacedUnfacedUnfaced
Interior/ExteriorInterior/ExteriorInterior/ExteriorInterior/ExteriorExterior
View ProductView ProductView ProductView Product

Specifications

Dimensions

Coverage Area (Sq.Ft)
200
Product Length (ft.)
50 ft
Product Thickness (in.)
0.25 in
Product Width (in.)
48 in

Details

Compatible Install Surface
Concrete,Plywood,Wood
Faced or Unfaced
Unfaced
Insulation Features
Formaldehyde Free
Insulation Location
Re-Siding
Insulation R-Value
R1
Insulation Type
Foam Board Insulation
Interior/Exterior
Exterior
Number of Pieces
1
Product Weight (lb.)
13.2 lb
Sheathing Size
50 ft. x 0.25 in. x 48 in.
Sheathing Type
XPS

Warranty / Certifications

Warranty Information
Limited Lifetime

Questions & Answers

113Questions18Answers

Are these boards somewhat flexible? Could they be applied to slightly curving walls?

Asked by zeph November 7, 2020
1
Answer

Hello zeph, Owens Corning 15psi and 25psi products have a 36" bending radius for the 1" board. With the FanFold being a lower psi and only 1/4" thick, it should be able to be applied to a slightly curved wall. Thank you for your inquiry!

Can I install this on a non-concrete floor prior to installing carpet padding and a carpet?

Asked by chief September 26, 2020
2
Answers

Hello chief, Owens Corning FanFold cannot be installed in the described application. The carpet and pad will not distribute any pressure points from heavy objects or even walking on the carpet. Because of this the FanFold could be compressed and it will not recover from compression. Thank you for your inquiry!

different information on Owens Corning website and Home Depot's. Is this faced or unfaced? Want to cut w/hot wire.

Asked by Rey September 16, 2020
2
Answers

Hello Rey, The Foamular FanFold board does not have a foil facing as some foam products do. However, there is a film facer on one side to provide some extra strength and damage control on the job site. Thank you for your inquiry!

Why is the seaming tape not sold in store and why can’t I find it online to purchase? Where can I buy it???

Asked by Jfk September 13, 2020
3
Answers

I just bought some today at home depot, you will find it in the adhesive tape section of the paint department.

can this be installed unfinished attic wood floor then carpet underlayment then carpet?

Asked by Frank August 27, 2020
2
Answers

Hello Frank, Owens Corning FanFold cannot be installed in the described application. The carpet and pad will not distribute any pressure points from heavy objects or even walking on the carpet. Because of this the FanFold could be compressed and it will not recover from compression. Thank you for your inquiry!

How long can it be exposed prior to siding

Asked by ray August 9, 2020
2
Answers

Hello Ray, we recommend covering Foamular products within 60 days. Thank you for your inquiry!

Can this be used under closed cell Spray Foam ?

Asked by D1NONLYSNSHN June 9, 2020
1
Answer

Hello D1NONLYSNSHN, we do not have recommendations for using Fanfold in this type of application. Thank you for your inquiry!

Where can I buy the 1/4 in Austin, Texas ?

Asked by Karl March 31, 2020
1
Answer

Hello Karl - Please contact your local Home Depot for product pricing and availability. Thank you for your inquiry!

Please advise if Owens Corning FOAMULAR 1/4 in. x 4 ft. x 50 ft. R-1 Fanfold Rigid Foam Board Ins...

Asked by Dave March 11, 2020
2
Answers

Never thought of that. But I think it's a pretty good idea.

Could this be used on basement floor under 1/2” pressure treated plywood then ramset or screwed into concrete floor ?

Asked by Dan February 22, 2020
2
Answers

Hello Dan - More information is needed in order to assist you. Please contact an Owens Corning representative at 1-800-GET-PINK for assistance with your project. Thank you for your inquiry!

FOAMULAR 1/4 in. x 4 ft. x 50 ft. R-1 Fanfold Rigid Foam Board Insulation Sheathing - page 2

Customer Reviews

  • 88 Customer Reviews
  • 4.6 out of 5 stars overall
100% of customers recommended.
Overall Ratings
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Easy to Install
Quality :
4
This insulation has a uniform consistency and is easy to install. Its compact packaging makes it easy to transport. I used a staple gun and box cutter to install. I would buy again.
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Product has a uniform consistency worked great
Product has a uniform consistency worked great
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Easy and quick to install.
Easy and quick to install.
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Worked great for my obscure purpose of insulating reptile tanks from the outside. Only complaint...
Worked great for my obscure purpose of insulating reptile tanks from the outside. Only complaint is I wish it came in 2x4 pieces. Only need 6ea 2x4 sections. I still have 38 feet left LOL.
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Rating provided by a verified purchaser
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Used it to put a little bit better wind barrier...
Used it to put a little bit better wind barrier an lil more insulation an it works AMAZING.
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Just a little bit more insulation before winter, worked well...
Just a little bit more insulation before winter, worked well for underneath some replaced metal siding.
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Why don't you carry the 3/8 fanfold insulation board?...
Why don't you carry the 3/8 fanfold insulation board?
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