SKU: 59277810533

Owens Corning FOAMULAR R-1 Extruded Polystyrene Fanfold Underlayment Insulation, 1/4 in. x 4 ft. x 50 ft., Square Edge

Sale price$63.49 Regular price$70.55
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Description

Owens Corning FOAMULAR R-1 Extruded Polystyrene Fanfold Underlayment Insulation, 1/4 in. x 4 ft. x 50 ft., Square EdgeFOAMULAR R 1 1 4 in. Fanfold XPS Underlayment Lightweight, moisture resistant XPS fanfold underlayment designed for re siding and sheathing applications. The 1 4 in. thick, 4 ft. x 50 ft. board delivers R 1 thermal performance and folds for fast coverage and easy handling. Key Features: Moisture Resistant XPS: Retains R value even after exposure to water. Easy Handling & Install: Fanfold design cuts and scores simply; no special tools required. Re

FOAMULAR R-1 1/4 in. Fanfold XPS Underlayment

Lightweight, moisture-resistant XPS fanfold underlayment designed for re-siding and sheathing applications. The 1/4 in. thick, 4 ft. x 50 ft. board delivers R-1 thermal performance and folds for fast coverage and easy handling.


Key Features:

  • Moisture-Resistant XPS: Retains R-value even after exposure to water.
  • Easy Handling & Install: Fanfold design cuts and scores simply; no special tools required.
  • Re-Siding Ready: Ideal as underlayment/sheathing for re-siding projects.
  • Durable Performance: Strong, lightweight board with long-term thermal retention.
  • Low-Emitting & Certified: GREENGUARD certified; formaldehyde-free blowing agent with reduced GWP.

Please check the Product Data Sheet Here


Specifications Table:

Specification Details
Insulation Type Foam Board Insulation (XPS)
Insulation R-Value R-1
Thickness 0.25 in (1/4 in.)
Width 48 in. (4 ft.)
Length 50 ft.
Coverage Area 200 sq. ft.
Edge Profile Square Edge
Faced or Unfaced Unfaced
Compatible Install Surface Concrete, Plywood, Wood
Interior/Exterior Interior; commonly used for re-siding underlayment
Number of Pieces 1
Pack Size 1
Product Weight 13.2 lb
Sheathing Type XPS
Insulation Features Formaldehyde Free; GREENGUARD Certified; Low water absorption; High R-value retention
Warranty Limited Lifetime

Frequently Asked Questions (FAQ):

Q: What are the dimensions and coverage?
A: Each fanfold measures 1/4 in. thick, 4 ft. wide, and 50 ft. long, covering 200 sq. ft.


Q: Where can I use this product?
A: Commonly used as re-siding underlayment or insulating sheathing over wood, plywood, or concrete surfaces.


Q: Is it faced?
A: No, this product is unfaced XPS foam board.


Q: How moisture resistant is it?
A: XPS construction provides low water absorption to help maintain R-value in wet conditions.


Q: Do I need special tools to install?
A: No. It scores, snaps, and cuts easily with standard utility knives.


Streamlined Sheathing with a Sleek, Modern Edge

This fanfold insulation creates a crisp, continuous plane behind new siding, elevating exteriors with a polished, tailored finish. I love its subtle flexibility—the panels fold effortlessly to glide across large walls, minimizing seams and visual clutter. Pair it with fiber-cement or cedar cladding to achieve a refined envelope and improved comfort. It’s a quiet luxury—performance you feel, with a look that’s impeccably composed.


Upgrade your re-siding project with FOAMULAR fanfold insulation for faster installs, lasting R-value, and a cleaner finish—add it to your cart today.

Installation

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 59277810533

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4.5 ★★★★★
Based on 26 reviews
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michele schmitz
Grantham, US
★★★★★ 3
Very thin. You get what you pay for.
Color: 01 - White, Size: Queen
You get what you pay for. I first noticed the softness which was great. The quality is very thin. They are cool which is great. I have not washed them yet. I would suggest washing them on cool and gentle by themselves. And because they are so thin I would fluff dry for an hour if you have that setting. The two things that damages clothes and sheets, etc. are if you have an agitator in your washer, those ruin clothes and the heat you choose for the fabric you’re drying I always wash my clothes on cold. I do not have an agitator anymore and on delicate and thin fabrics, I use fluff dry. It is cool, but it will dry, especially if it is thin and I’ve had to dry my fine delicates a little bit longer on fluff that way they don’t shrink because the shrinking comes in from the heat from the dryer so keep that in mind another good thing to remember if you got white sheets like I did is that when you use your detergent add a little bit of borax or laundry booster and they will help get them clean and sparkly white. I am on the fence about whether I would recommend this or not if you’re tight on money and you take good care of them I would recommend that you get them. I’m a linen freak and I buy mostly expensive sheets and I thought I would try this out so that’s where I’m at.
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Reviewed in the United States on May 26, 2026
M
Verified Purchase
Mariah Thiele
Fort Morgan, US
★★★★★ 5
Shower curtain liner clear
Color: Clear, Size: 72"W x 72"L (Pack of 1)
The packaged item arrived within a reasonable timeframe, quite promptly in fact, and was free of wrinkles. I am currently unable to assess the long-term durability of this product, as it appears somewhat thin. I will provide an updated review following more extensive use.
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Reviewed in the United States on May 27, 2026
H
Verified Purchase
Husam Khalifah
Carnegie, US
★★★★★ 5
Great quality and perfect length
Color: Clear, Size: 72"W x 78"L (Pack of 1)
This shower curtain liner works great and fits perfectly in my bathroom. The material feels durable, water stays inside the shower, and it dries quickly without a strong plastic smell. I also like the clear design because it keeps the bathroom looking clean and bright. The extra length is perfect for taller showers. Definitely a great value for the price.
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Reviewed in the United States on May 13, 2026
P
Verified Purchase
Pelican
Massapequa, US
★★★★★ 5
Great quality liner for a good price
Color: Clear, Size: 72"W x 72"L (Pack of 1)
Not all shower liners are equal! I don’t want to spend a fortune on one, but I do want decent quality. This liner is it! Clear so it lets light through, not too heavy or too light weight. The magnets actually work so the liner adheres to the tub and doesn’t get wrapped around you. Very pleased with the purchase.
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Reviewed in the United States on May 16, 2026
A
Verified Purchase
Amazon Customer
Lexington, US
★★★★★ 4
Decent D U P E for QT
Color: Clear Hot Pink, Size: 72"W x 72"L (Pack of 1)
Super cute. Love that it’s actually a vibrant hot pink (: (some other brands are much more diluted). This brand makes thicker versions in the colorful options (their palette seems like a nod to Quiet Town) but I went with the lighter weight one among their various options because it was cheaper. You can check out their store and find the thicker, more jelly like vibrant options for closer to $18 if you’re willing to pay more. I do think for how thin it is, it’s a little overpriced as most brands with this gauge of thickness run closer to $5-$8 and this one ran me about $9.99. Overall decent quality for a lightweight liner and decent vibrancy for a hot pink colored option. Just think it’s slightly overpriced for what you’re actually getting which is a liner on the lighter thinner side. I do like that it has a more shiny jelly like texture compared to regular thin shower liner competitors so that’s cool. Will add a pic later! Bottom line- if you’re just looking for a lightweight shower liner maybe with a little something extra like a fun color that has a smooth shiny texture, this one is decent if you don’t mind paying about $10 rather than $5-$8 like competitors. It is thin tho, make no mistake! But not so thin that it feels like it will rip immediately or anything like that. Their color options have nice saturation and modern tones- like their greens for example: one is a deep pine emerald and another a mint. Their orange is an amber hue. Whereas cheaper competitors that offer green and other colors are a more bland, corny tone. This brand offers varied levels of thickness/quality depending on how much you feel like spending (: gets the job done and brightens up the place. If you’re looking for a dupe for Quiet Town, you can find a somewhat decent vibe here in varies levels of quality.
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Reviewed in the United States on February 1, 2026

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