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

TJIs or TrussJoists?

FairviewTim | Posted in Construction Techniques on January 1, 2012 12:37pm

Hi All,

I’m doing some new year planning and that includes a new detached garage with a second-floor studio. Structure will be 24 x 28. I want to clear span the garage for workshop reasons so I’ll need floor joists that will span 23′-6″ without support. I like how easy it is to band block the truss joists when I’ll have rafter tails hung out over the top plate but the TJIs are cheaper. I know some folks here hate the truss joists but I’m thinking detailing will be much easier especially since I will have to double a few for the stairwell opening.

Your thoughts?

Tim

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

Replies

  1. TLE | Jan 01, 2012 01:19pm | #1

    Floor trusses

    I would usefloor trusses.

    You are probably going to be speced 13" tall on a 19.2" centers.

    Wood joists would be a minimum of 14" on a 16" center.

    As much as I love I-joists, the longer spans (over 20') result in a stiffer floor with trusses.

    Your local lumber yard can help with the specifications.

    Terry

    1. FairviewTim | Jan 01, 2012 01:32pm | #2

      Floor Trusses

      Hi Terry,

      By floor trusses, I assume you mean Truss joists and not TJIs?

      1. TLE | Jan 01, 2012 01:41pm | #3

        Yes, but the term Truss joists is not the typical name for them around here.

        When I see the phrase Truss joist I first think of the name Truss Joist Macmillion (sp?), one of the first manufactures of wood I-joists.

        Terry

        1. FairviewTim | Jan 01, 2012 02:45pm | #4

          Thanks & another thought for anyone

          It seems everyone has a regional name for anything . . . like rim joist and band joist (banding).

          Another thought I had after reading one of Mike Smith's posts:

          I might be able to get out even less expensive if I just run an LVL and use dimensional lumber for joists. I could run the beam across the 24' width and use 14 foot 2 x 10 SYP joists and maybe hangers to keep my full 10' ceiling height.

          Tim

  2. User avater
    BossHog | Jan 01, 2012 03:53pm | #5

    If you want to clear span that and have a decent floor, the floor system needs some depth to it. To span a 24' wide garage I'd want to see something 16" deep.

    Either I-joists or floor trusses would work. Just follow the receommendations of the manufacturer.

    Several eyars back I did a thread about floor vibration. I'd recommend reading it before you make a decision about the depth of your floor system:

    http://forums.finehomebuilding.com/breaktime/general-discussion/floor-vibration

    If you're doing a 1.5 story design, you might consider attic trusses. Just make sure you observe the same rules of thumb about length over depth ratio for the room suze.

    1. FairviewTim | Jan 02, 2012 04:55pm | #7

      Thanks, Boss

      I was leaning towards the TrimJoist (floor trusses with trim on the ends for rafter tail cuts and such) for ease of use. I know they're going to be 14" deep but I haven't done framing in 10 years and, although I still have all my necessary pneumatic and power tools and such, dimensional lumber is much easier to wrap my mind around. With all the squash blocks, web strengtheners, band joist issues and then having to frame and sheath the floor before setting rafters, not to mention figuring our how to double load bearing and point bearing joists with I-beams.

      Trusses would be great if I had the studio mapped out but the roof will be a double gable/pent roof design and that's easier to frame with sticks.

      Cheers,

      Tim

      1. User avater
        BossHog | Jan 03, 2012 10:22am | #9

        I have several comments.

        No way would I recommend using 14" deep floor trusses to span that far. Did ya read the thread on floor vibration?

        There's no reason to pay extra to get trimmable ends. Those are for angled walls or other odd situations. Just have them made the right length with a notch in the end for a ribbon board. 

        I don't understand your description of the roof style. However you frame it, make sure there are no roof loads applied to the floor trusses unless they're specifically designed for it.

        You don't need squash blocks, band joists, or web stiffeners with floor trusses.  Strongbacks are recommended, but they're no big deal. Just slide a couple of 2x6s in through the webs before you close in the ends.

        1. FairviewTim | Jan 03, 2012 04:46pm | #12

          L460 Span Charts

          say I can use a 14" 560 or 360 TJI or a J14 TrimJoist to span the 24' dimension no problem. L460 should be plenty stiff for a studio above a garage and have enough live load left over for a small dance party.

          As for my jumbly description of the roof; it's a gable roof running east-to-west on the 28' run with a dormer-gable on the south (front) that extends from the gable roof peak, and a full-width shed dormer on the north (rear) side.

          Strongbacks is a term I've heard but not real familiar with. Are they the same as web stiffeners? Again, regional terminology confusement requires some translation.

          Cheers and thanks for the help,

          Tim

          1. Piffin | Jan 03, 2012 07:31pm | #13

            Listen to Bosshog. He knows more about wood trusses than most anybody on the forums. It's his career.

          2. User avater
            BossHog | Jan 04, 2012 06:45am | #14

            Here's a good drawing of a strongback in a floor truss:

            http://www.chamberstruss.com/terms/Strongb.htm

            Your post started out with "say I can use a 14" 560 or 360 TJI or a J14 TrimJoist to span the 24' dimension no problem."

            I assume you left out who told you that. But I don't really care. My recommendation to use deeper floor members is based on a lot of years of experience and research.  As a result of that research I'm very conservative on floor design. Not everyone is.

            Whoever told you that was O.K. probably believes it. Ask them if they can tell you the frequency the floor will vibrate at. That will give you an idea if they know what they're talking about.

          3. FairviewTim | Jan 06, 2012 08:59pm | #17

            Thanks again, Boss

            I think I'm coming to a better understanding now. I went to a factory in Brevard where they actually build these things and learned pretty much what you're imparting here. While I hadn't planned to do more than use the second floor space for myself, I am going to rough in plumbing and such for future use and if someone down the line builds out for a mother-in-law apartment the stiffer floor will come into play when you start adding partition walls and furniture and appliances.

            So thanks, again for the lessons.

            Tim

          4. User avater
            BossHog | Jan 08, 2012 08:32am | #19

            I'm glad I could help.

  3. Piffin | Jan 02, 2012 07:08am | #6

    ???????????

    TJI stands for Truss joist International

    Their patent wore out so now lots of people make truss joists but they are basically the same thing

    Is it open web floor trusses you are thingking of comparing to? I prefer thoise when running utilities throught them, but for a simple garage see no need.

    As for rafters - what you can do is lay a plate across top of the floor system, then mount rafters to that. Works the same with either type of truss.

    1. FairviewTim | Jan 03, 2012 04:21pm | #10

      Hey Piffin

      Sorry for confusion, a lot of guys I used to frame and finish with used the term interchangeably and I guess it stuck with me. When I said truss joist I was thinking of something along the lines of TrimJoist or TrussJoist. TJI were pretty much anything that looked like an I-joist, like this:

      http://www.woodbywy.com/floors/f_TJI_joists.aspx

      I'm leaning that way but I've read some threads here over the years that weren't too kind to them. I do like buttoning everything up without drilling a bunch of wire and plumbing chases.

      Cheers,

      Tim

  4. User avater
    hammer1 | Jan 03, 2012 09:55am | #8

    We do quite a few garages with living space over, clear span below. I prefer to use a steel beam across the full span and then use conventional framing. Easy, inexpensive and you'll have a stiff floor for years to come.

    1. FairviewTim | Jan 03, 2012 04:24pm | #11

      Hmmm . . .

      There's another thought, but extra steps also. I guess there's still no easy way out.

  5. senojev | Jan 06, 2012 12:13pm | #15

    A few years ago, I built a house with a  30' (w) x 26' (L)clear span garage as part of the structure.  I ended up using 9.5/12 attic trusses which gave me a very good size room above with 8' ceilings and around 6' 6" headroom at the sidewalls.  The trusses were spaced 24" OC.  When I figured the extra cost of the trusses over materials and labor for framing a floor, sidewalls and roof, there was not much difference and the actual time savings were quite significant.

  6. senojev | Jan 06, 2012 12:13pm | #16

    A few years ago, I built a house with a  30' (w) x 26' (L)clear span garage as part of the structure.  I ended up using 9.5/12 attic trusses which gave me a very good size room above with 8' ceilings and around 6' 6" headroom at the sidewalls.  The trusses were spaced 24" OC.  When I figured the extra cost of the trusses over materials and labor for framing a floor, sidewalls and roof, there was not much difference and the actual time savings were quite significant.

    1. FairviewTim | Jan 06, 2012 09:40pm | #18

      Thanks for thinking of options . . .

      It's just me and a front loader up here on the mountain so smaller pieces would be easier on the old back. I'm kind of a loner when it comes to projects, although I do have friends who are always willing to help. I've seen their nailing patterns though . . .

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

Affordable Scans, Accurate Plans

Hover's smartphone app offers an easier way to get precise 3D scans.

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

  • Affordable Scans, Accurate Plans
  • FHB Summit 2025 — Design, Build, Business
  • A Summer Retreat Preserved in the Catskill Mountains
  • Fine Homebuilding Issue #332 Online Highlights

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 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

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