Floor Joist fix.

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Posts: 79
Joined: Sun Mar 11, 2012 3:56 pm

My parents have a mobile home and underneath the home there is a floor joist that has a knot busted out of it. I was thinking the best fix would be to screw a new 2x6 right up against and into the existing 2x6. Would this be the best fix?
Posts: 383
Joined: Mon Oct 25, 2010 9:53 pm
Location: Steuben County, NY

That should work fine. Some glue on the mating surfaces wouldn't hurt.
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Posts: 5696
Joined: Wed Feb 28, 2007 8:01 pm
Location: Weedsport, NY

About the only better way short of replacing the joist would be sistering a 2x6 on BOTH sides, Glue & screw.

"If I can't fix it, I can screw it up so bad no one else can either."
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Greg S
Posts: 541
Joined: Wed Jun 18, 2008 10:13 am
Location: Kingston Ontario Canada

A quality constructive adhesive is the key to sistering joists. In reality when the glue is dry the screws could be removed as they no longer serve any purpose.
An individual must enforce his own meaning in life and rise above the perceived conformity of the masses. (Anton LaVey)
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Joined: Tue Nov 11, 2008 6:12 pm
Location: wisconsin

Just to add to the good advice already posted. Screws don't provide good shear strength, meaning they will pull the boards together good but don't provide a lot of good up and down strength. Whereas a nail provides great shear strength but not a lot of strength to hold the boards together, nails will back out.

How big is this not? Unless it's 2" or bigger it really shouldn't be a problem. But if it is causing a problem then sistering another board is the best bet. Make it as long as you can. If you can fit a full 8 footer in there go for it. Use some construction adhesive like mentioned. Then either use bolts that will go all the way through and nuts on the other side with washers on each side. Or screw and nail it.