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
How-To

Hebel block

A great wall system that masons love to hate

By James Cameron, Kathleen Jardine Issue 123
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles
Hebel block can be cut with standard woodworking tools, such as a bandsaw. This saw was rented from Hebel.

Masons are accustomed to speedy work with block, but working with aerated autoclaved concrete (AAC) can be slow going. You need special trowels and mortar, and AAC requires precise drilling for the threaded rod that connects the foundation with the top plate.

Hebel makes its ACC blocks from a mix of cement, lime, sand, gypsum, water and an expanding agent. It’s hardened in a mold and then steam-cured under pressure. One thing masons will like is the weight–far less than typical concrete blocks. Although the material is available in different densities and sizes, the block we used measures 8 in. by 8 in. by 24 in. and weighs 28 lb. It can be cut with a handsaw, but we rented a bandsaw from Hebel that made cutting the block easy.

Although a masonry crew’s first experience with the material can be discouraging, paying well helps. We pay $4.50 per block. This rate compares with $1.50 per standard concrete-masonry unit. Hebel block isn’t cheap to buy, either. Blocks come to about $4.50 each with shipping. The Pearsons’ AAC walls cost about $9,000. Although this amount is more than typical construction, finishing costs were lower. The exterior gets a single coat of stucco, and interior walls a single coat of a soft, high-gypsum-content plaster. These factors made AAC affordable for the first floor of the Pearson house. Costs are higher for scaffolding work, so we didn’t use Hebel block in the gable ends.

Hebel block starts just above grade

Steel-reinforced walls: Threaded rod 5/8 in. in dia. runs from couplings at the top of foundation anchor bolts all the way through the top of a poured bond beam at the top of the wall. To accommodate the rod, each course of block must be drilled before it’s laid in place.

After pouring a concrete footing, we bring a standard concrete-block foundation up 10 in. to 12 in. above grade. Long 5/8-in. anchor bolts and couplers are set to the bottom of the first course of block, two or three per wall. The block is then filled with concrete. The first course of Hebel block is set in S-type cement mortar, but subsequent courses are set with a special thinset mortar provided by Hebel. Blocks are laid with no visible joint, so it is crucial that mortar be applied carefully. Hebel sells special trowels designed for the job.

As each course is set, blocks must be drilled precisely for threaded rod that eventually will run from the anchor bolts to the top plate. We drilled 2-1/4-in. holes to give ourselves plenty of wiggle room for the 5/8-in. rod. Each wall has two or three rods tying it to the foundation. At the top of the wall, we use a U-shaped Hebel block in which we pour a continuous concrete bond beam. Before the concrete bond beam is poured, we fill the holes for the rod with mortar.

Build bucks for doors and windows

We build door bucks from pressure-treated stock. We use construction adhesive and 6-in. nails provided by Hebel to anchor the bucks to the block as the walls are built around them. This sequencing allows us to control the size, placement, plumbness and squareness of all the door and window openings. We try to size windows so that they fit on even courses of block without having to cut a lot of small infill pieces.

Although you can order ACC door and window lintels, we prefer to pour our own bond beams in place. We used the U-shaped Hebel block for the form, and we reinforced each lintel with steel. The premade lintels are dangerously heavy to raise without the assistance of heavy equipment.

Mortar joints must be exact. A special trowel helps to ensure precise mortar thickness for block walls. Joints are flush with the wall.
Anchor bolts set in the concrete footing are attached to threaded rod running through the walls. Access is provided by a U-shaped cutout.
Each course of block must be drilled to accommodate 5/8-in. threaded rod that runs from the top plate to the foundation.

“So how do you wire this wonderful stuff?”

We’re asked that question often. It’s not that hard. Hebel will provide a router to cut channels in the walls for electrical conduit. But we think it’s easier to use a circular saw to slice grooves in block, then chunk out the waste with an old chisel or a screwdriver. Buy an inexpensive saw because the dust from one job probably will ruin it. We use a diamond-matrix blade for the cuts.

Before finishing ACC walls, we patch any irregularities with Hebel-block patch and use a Hebel toothed rasp to smooth the wall surfaces. Stucco is floated on the exterior walls to make a decorative, one-coat finish that needs no vapor barrier. We also plaster interior walls. Wire lath isn’t needed.

Photos: Kathleen Jardine and James Cameron; drawings: Scott Bricher

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

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

View Comments

  1. MandiTLavalley | Apr 28, 2018 05:38am | #1

    Great idea. Thanks for sharing this article.

  2. DonnaCIbrahim | May 10, 2018 12:36am | #2

    Good job you done here!

  3. AnnaBTorres | Jun 01, 2018 11:04pm | #3

    Thanks for sharing!

  4. CherylBGrant | Nov 02, 2018 02:00am | #4

    Great information here

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

Big Doors Have Big Challenges

Engineered materials and vacuum-press laminations prevent warping and keep a tall, flush-panel door from being excessively heavy.

Featured Video

How to Install Cable Rail Around Wood-Post Corners

Use these tips to keep cables tight and straight for a professional-looking deck-railing job.

Related Stories

  • One-Person Precision
  • FHB Podcast Segment: A Permanent Wood Foundation in the Adirondacks
  • Concrete Funnel
  • A Strong Case for Wood Foundations

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
  • FHB Podcast Segment: A Permanent Wood Foundation in the Adirondacks
  • Podcast 596: Broken Trusses, Frost-Protected Foundations, and Air Control Methods
  • Deck-Style Foundation for an Addition
  • Podcast 539: Seasonal Gaps in Flooring, AeroBarrier for Existing Homes, and Wood Foundations
View All

Site Work and Foundations

View All Site Work and Foundations Articles
  • Concrete Funnel
  • A Strong Case for Wood Foundations
  • Podcast 596: Broken Trusses, Frost-Protected Foundations, and Air Control Methods
View All Site Work and Foundations Articles

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 70%

Subscribe

You have 1 free article remaining.

Get complete site access, including thousands of videos, how-to tips, tool reviews, and design features.

Start your FREE trial

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