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
Tips & Techniques

Sandbags as Concrete-Form Anchors

By Charles Miller Issue 142
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Jonathan White’s method for anchoring pyramid-shaped footing forms on a sloped site (see Preventing pier-form uplift) brought to mind another approach that I have used to solve similar problems. As shown in the drawings, a combination of struts and sandbags can often be a suitable substitute for conventional anchorages when applied in certain applications. Rocky soil or winter conditions are two such situations when driving stakes into the ground just won’t work. Strut-braced forms also have the advantage of not obstructing the mouth of the form, and they don’t require the loss of valuable anchorage materials, such as threaded rods, inside the cast concrete.

Please note that I’ve deliberately not given any dimensions to these configurations. They would depend entirely on the specific size and shape of the form being used. For more detailed information on formwork, I suggest you contact the American Concrete Institute (www.aci-int.org).

To use this method, I first place my form on the footer or subgrade to evaluate the working clearances and the best approach path for the concrete. Then I use whatever scraps of furring strips or 2x3s I have available as strut material. I attach them parallel to grade and make them of sufficient length to project well beyond the form. They should stay clear of my working space and my approach path.

I then fill sandbags with whatever backfill is handy and place them atop the struts in sufficient quantity to counteract the weight of the concrete in the form. I am typically working with post pedestals in the 1-cu. ft. to 2-cu. ft. range, and it’s easy to pile on more than enough bags to deal with these loads. My criteria is to use enough bags that when I shove the form hard, it shows no appreciable movement. And I keep plenty of bags on hand should I need more bracing.

The sandbags should be placed so that they drape over the struts and make positive contact with the ground or with additional sandbags placed below the struts, as shown in elevation No. 2. On occasion I have also placed additional bags around the base of the forms to provide more lateral and torsional resistance. The critical thing to keep in mind is that concrete is heavy, is surprisingly plastic and prefers to assume the general shape of a cow pie rather than the shape you have in mind. It never hurts to overbuild or overbrace forms more than you think is necessary.

By the way, 25-lb. and 50-lb. woven polyfiber seed and feed bags are excellent for sandbags. They are likely to be available for free from your landscape subs and local livestock farms.

—Christopher T. Gale, Fallston, MD

Edited and illustrated by Charles Miller

From Fine Homebuilding #142

Sign up for the Fine Homebuilding Tip of the Day and get daily tips and special offers delivered to 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
×

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

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

More Tips & Techniques

View All
  • Precut Bottom Plates in Doorways
  • Prevent Paint Bridging With Picks
  • Stop Cracks at Corners
  • Sticker Smudge Solution
View All

Up Next

Video Shorts

Featured Story

FHB Podcast Segment: Patching Drywall Near a Shower

Learn how to patch drywall above a fiberglass shower without totally redoing everything.

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

  • 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

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

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