DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Building & Construction (
-   -   Leveling joists in crawl space (

zero80 03-15-2014 07:25 PM

Leveling joists in crawl space
Currently are living room floor has a slight sag near the wall. After having a structural engineer look at the problem its deflection on the joist do to load. Based on specs from the SE I built 3 2/12 to make a big beam to put in the middle of the sag to hopefully eliminate it. My question is what the best way to level the floor in crawl space? I was thinking about pulling string across all joist get that level then measure up from the string to the joist to find the on even joist. Thoughts or suggestions ?

tony.g 03-16-2014 07:52 AM

If the SE has sized you a beam, he should at least advise on a method of levelling the joists - if that is actually possible.
If it's an older house, and the sag has been caused by the long-term loading of a wall, it's possible the joists may be permanently bowed because timber undergoes long-term creep deformation under load. If you then try to level it - eg by jacking - it may lift or put stress on other parts.

Nailbags 03-16-2014 09:37 AM

the best way I can think of it place that beam use a steel I beam and place it. when you jack it up slowly look for day light between the joists and beam shim accordingly so that it is equally distributed. also you may have to shim between the floor and the joists as well. given that you have a reverse action going on. so go slow take your time it should come out just fine.

stadry 03-17-2014 02:39 AM

screw jacks ONLY,,, hydraulics are too fast & uncontrollable imn-s-hfo :laughing: so what if it takes a while to fix it ? it probably took longer for the damage to occur

zero80 03-17-2014 07:56 AM

The beam already in place. I am using screw jacks three feet apart sitting on top of 2ft 2/12. I am guessing the string idea is the best to go with.

Gary in WA 03-18-2014 09:57 PM

The string line will sag, unless nylon and pulled extremely tight. When stringing for level, I add a second nail in front/diagonally across the string nail because I reef so hard on the string- one nail can pull out. Optimum; rent a laser level, second choice- string line. Even with nylon and a good pull, it will sag 1/8" in 25'. After attaching one end, make a loop for the other nail head by twisting the loop 3-4 times before putting it over the nail. With one hand pulling the string slack while other is pulling the slack end (past the nail)-- the string will tighten and stay there because of the twists you put in (with a little movement of hand/string back toward the nail- at right angle from- while keeping the tension). Add a final couple of winds around the string at the head to keep it there-- when tight enough (when you grab the taut string and it won't pull any tighter without hurting your hand).


All times are GMT -5. The time now is 02:18 PM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1