FHB Logo Facebook LinkedIn Email Pinterest Twitter 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
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In
Tools & Materials

Magnesium Oxide Does It All

Impressive strength, as well as its fire, mold, and insect resistance, make MgO board suitable for a wide range of applications.

By Patrick McCombe Issue 269 - Aug/Sept 2017

If you’re not familiar with magnesium oxide (MgO) board, you’re in good company, as it’s only starting to make its way to this country from widespread use in Asia. Extremegreen’s MgO board’s impressive strength, as well as its fire, mold, and insect resistance, make it suitable for a wide range of applications, from tile backer and wall panels to exterior trim and lap siding.

Bob Nilsen, a builder from Millbrook, N.Y., had to tackle the learning curve when MgO board was specified for 1/2-in. by 6-in. lap siding on a recent project. He told me that cuts are smooth and easy with conventional carbide-tipped circular saw blades and that ordinary bimetal jigsaw and multi­tool blades work fine for cutting around penetrations. His crew fastened the siding with pneumatic roof nailers, but, according to the maker, it can also be fastened with high-quality screws (conventional black drywall screws sometimes snap off), framing nails, and siding nails. Nilsen told me he liked working with the material better than fiber cement, because the dust wasn’t as irritating and the composition is easier on cutting tools. He also told me that throwing the material in a bucket of water for two months had no effect.

Builders who work in multifamily and commercial projects might see MgO board sooner than residential builders, because the material’s extreme fire resistance can eliminate the need for a second layer of drywall (and its associated material and labor costs) in many fire-rated assemblies.

Extremegreen MgO board is available through BlueLinx at local lumberyards. As of June 2017, distribution covers most of the United States, and nationwide availability is expected soon. In small quantities, 1/2-in. MgO board sells for $1.10 per sq. ft., 5/8-in. for $1.40 per sq. ft., and 3/4-in. for $1.60 per sq. ft.

Sign up for eletters today and get the latest how-to from Fine Homebuilding, plus special offers.

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
×

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

New Feature

Fine Homebuilding Forums

Ask questions, offer advice, and share your work

View Comments

  1. BradWalk | Oct 03, 2019 04:31pm | #1

    Does Extremegreen manufacture this product in the USA? Is there any North American manufacturers?

  2. Haverlock2022 | Mar 01, 2023 12:35pm | #2

    Note: do not use metal nails, screws, etc unless there coated with an Epoxy like coated steel screws which have an epoxy based polymer resin overcoat. The epoxy coating provides excellent corrosion resistance and is designed to adhere to the screw, even after it's inserted into MGO annd or other synthetic products. Anything other then a coated screw may break or crack the MGO boards?

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Up Next

Video Shorts

Featured Story

Directing Drainage Under a Driveway

A properly installed 4-in. corrugated drainage pipe running under a driveway can withstand the pressure of a 40,000-lb. truck.

Featured Video

Micro-Adjust Deck-Baluster Spacing for an Eye-Deceiving Layout

No math, no measuring—just a simple jig made from an elastic band is all you need to lay out a good-looking deck railing.

Related Stories

  • Meet Current Energy Codes with Continuous Insulation
  • Framing a Second Story on an Existing House
  • How Lumber is Produced
  • Finishing Drywall With Seamless Results

Discussion Forum

Recent Posts and Replies

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

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

Video

View All Videos
  • Framing a Second Story on an Existing House
  • Airtight Corner for a Variety of Cladding Types
  • Podcast 502: PRO TALK With Lumberyard Manager Cesar Gonzalez
  • FHB Podcast: Special Edition With Neil Freidberg of Louisiana Pacific and Kyle Stumpenhorst of RR Buildings
View All

Lumber and Sheet Goods

View All Lumber and Sheet Goods Articles
  • Staining Pressure-Treated Porch Posts
  • Best Deck for a Steel Roof
  • Protect Board Ends to Prevent Rot
  • Advanced Framing with LSL Studs
View All Lumber and Sheet Goods Articles

BOOKS, DVDs, & MERCH

Shop the Store
  • 2023 Tool Guide
    Buy Now
  • Code Check Complete 3rd Edition
    Buy Now
  • 2022 Fine Homebuilding Archive
    Buy Now
  • Pretty Good House
    Buy Now
  • Shop the Store

Fine Homebuilding Magazine

  • Issue 318 - October 2023
    • Make Mudsills Square and Level
    • Turn Up the Heat With Induction Cooktops
    • The Fine Homebuilding Interview: Lloyd Alter
  • Issue 317 - Aug/Sept 2023
    • Finishing Drywall With Seamless Results
    • A Flat Roof in a Cold Climate
    • Compact Cordless Shop Vacs
  • Issue 316 - July 2023
    • Timber-Framed Solar Canopies
    • Build a Transom Above a Stock Door
    • Understanding Toilet Design and Efficiency
  • Issue 315 - June 2023
    • How to Craft a Copper Roof
    • 5 Lessons from Building in a Cold Climate
    • The Advantages of Cellular PVC Siding
  • Issue 314 - April/May 2023
    • 7 Options for Countertops
    • Tool Test: Wood-Boring Bits
    • Critical Details for Ductless Heat Pumps

Fine Homebuilding

Follow

  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok
  • twitter

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

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences

Taunton Network

  • Green Building Advisor
  • Fine Woodworking
  • Fine Gardening
  • Threads
  • About
  • Contact
  • Advertise
  • Careers
  • Copyright
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2023 The Taunton Press, Inc. All rights reserved.

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
  • 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

Shop the Store

  • Books
  • DVDs
  • Taunton Workshops

More

  • FHB Ambassadors
  • Reader Projects
  • Podcast
  • 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

  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok
  • twitter

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 70%

Subscribe

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