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

Floor joist truss repair

| Posted in Construction Techniques on February 21, 2006 02:07am

Hello all,

This is my first post to this forum. I have a sagging floor in my kitchen and I thought it was just sagging floor joists (which are trusses, see “floor joist trusses 0001”). I did a cursory inspection and decided to “fix” the problem with 2×6 strongbacks (see FHB 166 p.104). However, on closer inspection, I found that one of the trusses had a cracked bottom chord (see “floor joist trusses 0010”) and it was sagging at almost 1 inch per foot! (see “floor joist trusses 0006) The gusset plates were even pulling from the top chord (see “floor joist trusses 0004). Then I noticed that the installer had butchered the joist right next to this one (see “floor joist trusses 0007).

So, to solve the problem, I was going to sister a 6 to 7 foot long 2×6 to the lower chord of each truss. The end of the 2×6 would rest on edge on the sill plate next to the truss and the bottom edge would follow the lower chord of the truss. I would jack up the truss and 2×6 from below until the truss was straight (no sag) and then nail through the 2×6 into the lower chord and any webbing members that I could. I would avoid nailing through the gusset plates.

What do you think? Am I missing anything? I know I’ll be slightly modifying the “truss-like” effect by nailing the webbing at locations along their length, but I think it will be structurally sound.

Thanks for your help,

Bob

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

Replies

  1. gzajac | Feb 21, 2006 02:25am | #1

    Bob

    It looks like someone re-engineered these trusses for you already.Picture 0007 looks like the end was cut off, or it was made out of a longer truss.I can't tell from the pictures how the other bearing points are, probably not pretty.

    From your profile, you are an engineer. I wouldn't trust an engineer over the net to solve your problem, a local one is needed in this case.

    When the engineer comes, have him look at the whole system. Don't wait to long.

    Greg in cold Connecticut

    1. User avater
      fengelman | Feb 21, 2006 02:58am | #2

      just a thought, but why not jack the offending trusses up, and instead of sistering a 2x6, why not a couple of pieces of 1/2 or 3/4 ply wood, glued and screwed to the trusses...the full depth of the trusses?  with that kind of access, that's what I would do...

      1. User avater
        PeteDraganic | Feb 21, 2006 07:33am | #7

        Fengleman,

        My thoughts exactly.  Adding full-height plywood scabs to the side or sides of the truss assemblies should do wonders.

        Screw and glue.

        The difference between stupidity and genius is that genius has its limits. -Albert Einstein

        http://www.peteforgovernor.com

  2. User avater
    BossHog | Feb 21, 2006 04:14am | #3

    As someone already pointed out, your trusses have been altered somewhere along the line. You icture titled "floor_joist_trusses_0007" shows one that's been cut off and not repaired AT ALL. Not a good thing.

    The plate pulled out of one of those joints is also a problem. Again, it's likely damage from back when they were installed.

    Judging from the looks of them, I'd guess the house is 8 to 10 years old? So contacting the truss manufacturer and/or the original builder isn't likely to do much.

    Your proposed solution of nailing a 2X6 alongside them isn't going to do anything but waste time and get in the way of eventually fixing them correctly.

    I'd suggest contacting a local truss manufacturer, and explaining the situation to them. They can likey refer you to an engineer who's familiar with trusses and truss repairs.

    This isn't something you can get a solution for on the internet.

    This morning I woke up to the unmistakable scent of pigs in a blanket. That's the price you pay for letting the relatives stay over.
    1. Bob C. | Feb 21, 2006 05:32am | #5

      Boss Hog,

      Thanks for the recommendation. I just emailed a local truss manufacturing company. They might actually be the company that supplied the trusses in the first place! I'll update the forum when I get a response.

      Thanks to everyone for their time and help.

      Bob

      1. FCOH | Feb 21, 2006 07:22am | #6

        Bob,

        Ive repaired these in the past and weve alvays used 1/2" or 3/4" osb. 

        Just like the other guy suggested, rip the osb or plywood to whatever the height of your floor truss is jack up the joist, glue it on the side and nail the sh*t out of it.  Do this to both sides and stagger your joints. 

         

        Matt

        1. User avater
          BossHog | Feb 21, 2006 03:05pm | #8

          Adding plywood isn't enough. You have to know WHERE to add the plywood, where to put the joints at, what thickness of plywood to use, and the nailing pattern. That all has to be figured out based on the forces in the members and what's damaged. Every repair is different.
          Q: What do you get when you mate an elephant with a poodle?A: A dead poodle.

  3. Piffin | Feb 21, 2006 05:11am | #4

    Boss is right, the only thing you can do with a 2x6 there is to whack the 'builder' over the head with it, then break all his fingers with it so he will never butcher another job this bad again.

     

     

    Welcome to the
    Taunton University of
    Knowledge FHB Campus at Breaktime.
     where ...
    Excellence is its own reward!

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

Choosing a Paintbrush

Tips for picking the right paintbrush based on paint type, surface, and personal comfort.

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

  • Midcentury Home for a Modern Family
  • The New Old Colonial
  • Modern and Minimal in the Woods
  • Bryce Hollingsworth, Dry-Stone Waller

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 333 - August/September 2025
    • A Practical Perfect Wall
    • Landscape Lighting Essentials
    • Repairing a Modern Window Sash
  • Issue 332 - July 2025
    • Custom Built-ins With Job-Site Tools
    • Fight House Fires Through Design
    • Making the Move to Multifamily
  • 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

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

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