FHB Logo Facebook LinkedIn Email Pinterest Twitter X Instagram Tiktok YouTube Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Restoration
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In

Discussion Forum

Discussion Forum

Extruded vs Expanded Polystyrene for …

| Posted in Energy, Heating & Insulation on January 12, 2002 02:40am

*
My timberframers are recommending a stress skin panel made by a company out of Fond-du-Lac Wi that uses Expanded foam(the white kind) for their panels. The tech heads I talked to there said the chief reason was because their parent company makes Expanded foam. They’re saying a nominal 12″ panel (11 1/4″) is R46, will support 64 lbs/sq ft at a nine ft span between trusses and costs $4.00 per square ft. That’s with 7/16″ OSB on both sides.

Does this like it will work and is it a good deal? I always thought Expanded was a little weaker than Extruded.

The Wood Doc

Reply
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Replies

  1. Gabe_Martel | Jan 11, 2002 04:52am | #1

    *
    The main concern I would have is a failure in the exterior skin.

    Water penetration into the white beaded insulation would spell disaster during freeze thaw cycles.

    Just a thought

    Gabe

    1. splintergroupie_ | Jan 11, 2002 06:30am | #2

      *Here's link on our topic: http://www.eren.doe.gov/consumerinfo/refbriefs/bd1.htmlThe relevant paragraphs:i EPS and XPS Panelsi The majority of SIPs are manufactured with expanded polystyrene (EPS.) This foam is commonly known as beadboard. This type of SIP has a nominal R-value of about 4 per inch (2.5 cm) of thickness. Unlike other types of foam insulation, beadboard uses pentane as the expanding agent. Extruded Polystyrene (XPS), with R values of 5 per inch (2.5 cm) of thickness is also sometimes found. It uses a hydrochlorofluorocarbon (HCFC) gas as the expanding agent.Basically, the beadboard is the cheapest of the faom boards. There's also a type where they place the panels and shoot expanding polyurethane between them (expensive and rare). The foam board ones are laminated and glued together. SIPA -- Structural Insulated Panel Assoc. -- is also a good source of info.

      1. Kerr | Jan 11, 2002 08:37pm | #3

        *The stress in any thing rigid is carried by the outermost fibers.So, I guess that the kind of foam used is not a real big factor in the overall strength of an SIP. I think that the type of foam has most to do with the R value, water resistance, the kind of equipment the mfr has invested in and stuff like that.Strength-wise, the key factors are gonna be(in this order): - thickness of the OSB layers - quality of bond between the OSB and the foam - thickness of the foam - stiffness of the foam

        1. Kerr | Jan 11, 2002 09:14pm | #4

          *correction!the biggest factor will be the DISTANCE between the two outer layers, then the strength of those layers.so the order should be:- thickness of the foam- thickness of the OSB layers - quality of bond between the OSB and the foam - stiffness of the foam

          1. Jeff_Maras | Jan 12, 2002 02:40am | #5

            *I spoke with the tech heads today in regards to fire resistance of the panels. He said that in the last seven years he only remembers one job that installed drywall. I am planning on putting 3/4" T&G paneling on the inside which he said would increase the burn thru time compared to just 7/16" OSBI'm wondering if putting up 1/2" fire rated drywall then 3/4" T&G prior to craning(is that a word?)would be a smart idea. He said another option is having the OSB manufacturer add a 3/16 cementious coating to the inside which should give an additional 15 minutes of fire resistance. This would bumb up the cost about 75cents per sq ft. Any Thoughts?The Wood Doctor

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Video Shorts

Categories

  • Business
  • Code Questions
  • Construction Techniques
  • Energy, Heating & Insulation
  • General Discussion
  • Help/Work Wanted
  • Photo Gallery
  • Reader Classified
  • Tools for Home Building

Discussion Forum

Recent Posts and Replies

  • |
  • |
  • |
  • |
  • |
  • |
View More Create Post

Up Next

Video Shorts

Featured Story

Podcast Episode 684: Masonry Heaters, Whole-House Ventilation, and Porch Flooring

Listeners write in about fireplaces and ask questions about whole-house ventilation, traditional porch flooring, and gutter sealants.

Featured Video

Video: Build a Fireplace, Brick by Brick

Watch mason Mike Mehaffey construct a traditional-style fireplace that burns well and meets current building codes.

Related Stories

  • Podcast Episode 684: Masonry Heaters, Whole-House Ventilation, and Porch Flooring
  • FHB Podcast Segment: Repairing an Old Home While Maintaining Its Integrity
  • Tools and Gear for the Moms Who Get it Done
  • An Easier Method for Mitered Head Casings

Highlights

Fine Homebuilding All Access
Fine Homebuilding Podcast
Tool Tech
Plus, get an extra 20% off with code GIFT20

"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Fine Homebuilding Magazine

  • Issue 331 - June 2025
    • A More Resilient Roof
    • Tool Test: You Need a Drywall Sander
    • Ducted vs. Ductless Heat Pumps
  • Issue 330 - April/May 2025
    • Deck Details for Durability
    • FAQs on HPWHs
    • 10 Tips for a Long-Lasting Paint Job
  • Issue 329 - Feb/Mar 2025
    • Smart Foundation for a Small Addition
    • A Kominka Comes West
    • Making Small Kitchens Work
  • Issue 328 - Dec/Jan 2024
    • How a Pro Replaces Columns
    • Passive House 3.0
    • Tool Test: Compact Line Lasers
  • Issue 327 - November 2024
    • Repairing Damaged Walls and Ceilings
    • Plumbing Protection
    • Talking Shop

Fine Home Building

Newsletter Sign-up

  • Fine Homebuilding

    Home building tips, offers, and expert advice in your inbox.

  • Green Building Advisor

    Building science and energy efficiency advice, plus special offers, in your inbox.

  • Old House Journal

    Repair, renovation, and restoration tips, plus special offers, in your inbox.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Follow

  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X
  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences
  • About
  • Contact
  • Advertise
  • Careers
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2025 Active Interest Media. All rights reserved.

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

  • Home Group
  • Antique Trader
  • Arts & Crafts Homes
  • Bank Note Reporter
  • Cabin Life
  • Cuisine at Home
  • Fine Gardening
  • Fine Woodworking
  • Green Building Advisor
  • Garden Gate
  • Horticulture
  • Keep Craft Alive
  • Log Home Living
  • Military Trader/Vehicles
  • Numismatic News
  • Numismaster
  • Old Cars Weekly
  • Old House Journal
  • Period Homes
  • Popular Woodworking
  • Script
  • ShopNotes
  • Sports Collectors Digest
  • Threads
  • Timber Home Living
  • Traditional Building
  • Woodsmith
  • World Coin News
  • Writer's Digest
Active Interest Media logo
X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Project Guides
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Online Learning

  • Courses
  • Project Guides
  • Reader Projects
  • Podcast

More

  • FHB Ambassadors
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • X
  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 81%

Subscribe

Enjoy unlimited access to Fine Homebuilding. Join Now

Already a member? Log in

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in

Privacy Policy Update

We use cookies, pixels, script and other tracking technologies to analyze and improve our service, to improve and personalize content, and for advertising to you. We also share information about your use of our site with third-party social media, advertising and analytics partners. You can view our Privacy Policy here and our Terms of Use here.

Cookies

Analytics

These cookies help us track site metrics to improve our sites and provide a better user experience.

Advertising/Social Media

These cookies are used to serve advertisements aligned with your interests.

Essential

These cookies are required to provide basic functions like page navigation and access to secure areas of the website.

Delete My Data

Delete all cookies and associated data