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

100 Year Old Cracked Floor Joists

maxchase | Posted in Construction Techniques on March 26, 2004 02:45am

I am working on a 100 year old Victorian.  Several of the floor joists have split.

Due to plumbing and wiring, it is impossible to sister new joists to the old joists. 

I was thinking of gluing and nailing two plies of 3/4 inch plywood to the split joists.  I am sure that I could slip the 8 ft length into the tight space.

The joists that need to be repaired are about 15 feet long so it would take two lengths of plywood end to end and then a second layer overlapping the joints.

Has anyone else had to deal with this type of situation?  Or have an opinion on what I am thinking of doing? 

Thanks.

Mike

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

Replies

  1. SunnySlopes | Mar 26, 2004 03:32am | #1

    Mike,

        If the wiring will be in the way of the new joists won't it also be in the way of the ply?    What is above?   living space, attic floor etc.. 

    "One measurement is worth a thousand expert opinions"
    1. maxchase | Mar 26, 2004 03:46am | #3

      The joists are in a heated basement with finished living space above. 

      The plywood would fit because it would only be 8 ft lenghts. The wiring and plumbing is about 1/3 of the way between the houses primary support beam and the foundation wall.

      1. davidmeiland | Mar 26, 2004 03:51am | #4

        How much plumbing and wiring are we talking about? Why not just peel it out of the way, do your structural repair correctly with a single length of 2x material, redrill the new and splice the wire and pipe?

        1. maxchase | Mar 26, 2004 04:01am | #6

          I hear you on the "right way" to do it. 

          Unfortunatly, the plumbing is a real sensitive topic.  The plumbing which is in the way is for the heating system which is probably 80 yrs old.  It is old cast pipeing not copper.  There is a very real posibility of a serious snowball effect if we start messing with those pipes.  That is why I am working on an alternative plan.

  2. mike4244 | Mar 26, 2004 03:36am | #2

    If you can prop the joists back up to a straight line your solution would probably work. If the joists have a permanent bow in them the best you can do is saw off high spots and shim low spots in joists, after installing plywood.I once tried to straighten 3x5 1/2 joists in a victorian much older than yours ( circa 1845) with plywood nailed and glued. These joists sagged about 1 -1/2"  in the center. Wound up removing them and install engineered joists.

    mike

    1. maxchase | Mar 26, 2004 03:51am | #5

      beleive it or not, the joists are actually straight.  They did not CRACK due to weight, they look like the SPLIT as a result of drying.  The joist only support the living space above.  They are not really carying any load other than people and furniture.

      1. mike4244 | Mar 26, 2004 07:12pm | #11

        Mike, go ahead and nail and glue the plywood. It will work fine, you may have to remove any loose splinters if there are any.I would use 10d  nails and subfloor adhesive, plenty of nails staggered.Glad to hear the joists are straight.

        mike

  3. BillW | Mar 26, 2004 12:12pm | #7

    Mike - I read about a technique (back issue of FHB?) using a metal strap about the length of the joist.  It's nailed at the top of one end, run at an angle down to the bottom of the joist in the center of the span, wrapped around and run back up the other side of the joist to the opposite corner, nailed all along its length.  Apparently it adds tremendously to the joist's ability to resist deflection, and may compensate for the split.

    It sounds like a really elegant solution, especially because you could probably weave it through wires and pipes. 

    Maybe one of the many experts here could comment on this technique, since I've never actually tried this myself and I'm not a structural engineer.

    Bill.

  4. Fitzcarpentr | Mar 26, 2004 04:10pm | #8

    If they ain't sagging, don't fix what ain't broke.....

    Those old timbers tended split, but you still have enough as far as Bottom Fibre Stress and Modulus of Elasticity, for the dead/live loads I'm sure. Those timbers are usually very clean(no large through-knots) so probably the only concern I would look at is if the whole timber/joist has full bearing onto/into the sill. They use to mortise them inand half the joist was hanging off the sill/ carring beams. If that looks questionable, I'd concentrate on supporting the bottom edges @ the walls.(angle iron, stud wall built on the flat)

    I don't think any of this is a concern tho, its been there 100+years

  5. Dave45 | Mar 26, 2004 04:24pm | #9

    Could you run lag bolts vertically into the joists?  If they haven't sagged, the bolts would pin the joist back together.

  6. User avater
    rjw | Mar 26, 2004 04:25pm | #10

    Are they cracked or checked? Old joists often have checks, a form of splitting which rarely affectes structural strength.

    Take a hard look at the ends of the splits, is the wood inside darked, or does it look fresh?

    Is the floor above bouncy?

    _______________________


    Tool Donations Sought

    I'm matching tool donors to a church mission to Haiti - we're shipping a bus converted to a medical facility in (now it looks like) April and can fill it with clothes, tools and all sorts of stuff needed in that poorest of all countries. A few hand tools or power tools can provide a livelihood for an otherwise destitute family. Please email me if you have tools to donate.

    Thanks to Jeff and David and Jim and Rich and Steven and Mark and Jason and Shep and Jen and Mike and Joe and Bill and Ken for their offers!

    Several donations have arrived! Thanks and God bless!


  7. ANDYBUILD | Mar 26, 2004 08:37pm | #12

    Mike

           In my circa:1680 house I bought a year and a half ago the walls were sagging big time.

    When we removed the exterior shingles along with two dbl windows we could see the huge oak beam above it seriously cracked.

    The dopes that obviously installed those dbl windows years ago cut out the studs and didnt replace em' with anything but windows.

    The walls above it were braced to the addition I added on and the old timber was  cut out and then added three 20'x18" lam beams in its place.

    Whewwwwwwwww

    Be wall.I mean well

                                   andy

    "My life is my practice"

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 694: Bath Fans, Too Many Minisplits, and Second-Story Additions

Listeners write in about fire-rated doors, using seven minisplits for cooling, and how to build a second-story addition.

Featured Video

SawStop's Portable Tablesaw is Bigger and Better Than Before

The 10-in. Jobsite Saw PRO has a wider table, a new dust-control port, and a more versatile fence, along with the same reliable safety mechanism included in all SawStop tablesaws.

Related Stories

  • xoxo test post 3
  • xoxo test post 2
  • xoxo test post 1
  • Midcentury Home for a Modern Family

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