Found A Broken Floor Joist In My House

[blair683]

I have a question concerning a broken/ cracked floor joist in my house. My house was built in 1918 and is a large 2 story house. The other day me and my dad was in the basement and he pointed a broken floor joist out to me. I never noticed it before but now I cant stop looking at it when I am down there. I feel like the break is fairly new because I think I would have noticed before. I attached some pictures of it below.

The crack seems to be directly below my refrigerator. My basement is completely dry and always heated/ cooled. The joist is an ancient, actual 2"x8" maybe 10" (I will have to measure it again). They are harder then **** to nail or screw through.

How concerned do you guys think I should be with this? I was thinking of jacking it up with a bottle jack until the crack closes. Then gluing a new 2"x8" board to the side of joist with liguid nail. Then bolt and nut through the two boards on both sides of the crack. Or could this be something more structual? Any information is appreciated. I can get more pictures if needed.

 

[lakeroadster]

Have you thought about through bolting steel fish plates on both sides instead of adding wood? Similar to a timber frame splice?

 

[quattro_sinko]

You're on the right track for repairing it. I would use PL Polyurethane and Screws (both sides, new to old, old to new) to sister a new 2x to it though. If you use a bottle jack to lift it (before sistering, go slow and be cautious. Let the adhesive set up (48 hours) before removing the jack. I think there's a natural "defect" on the joist in the photo, it looks like it's cracking at an old knot.

 

[ItsNemo]

Jack it level, sister another piece of dimensional lumber to it (glue and screw) and make sure you run it as close to the full length (if not the full length if you can get it in) as possible.

 

[blair683]

The one side I have easy access to and could run a new board almost full length. The other side I can only get a few feet past the crack on either side of the crack.

 

[ard]

Dont jack it up 'till it closes'. It might not close, and you could hose other things in the home.

Id try to understand what happened to cuase that...anything settling? Anyone do other work? (like jack up the second floor with a bottle jack on that joist?!?)

The 'fix' is after the cause is determined. Or failing to ID a cuase, the determination that there is nothing active going on. Level the floor, or a 1/16th over, sister on a joist.

my 2 cents

 

[firebirdparts]

Scab it, no problem.

 

[blair683]

I can not think of anything that could have caused this. About 6 years ago we had a company water proof our basement. They broke up the floor around the inside perimeter and installed drains under the walls. Other than that, the house seems to be amazing level and straight especially for its age. We have original plaster in most of the house and we never ripped it out because of how good of shape it's in. We purchased the house off of the original family that built the house. We have two kids so I feel like the house gets a lot more traffic than it has before we moved in. Every time my kids and their friends are jumping through the house it makes me think of the broken floor noise.

 

[ambenz]

Age happens...just don't worry too much about it.
Lots of good advice on the repairs...I would go with the full new board and bolt them together.

 

[The Cobbler]

scab another joist to the side you can get to and you will be good. looks like a chimney there, and the 2 additional joists are bearing their weight to 2 outside joists . these days those outer joists would at least be doubled up.
I would jack it up to be inline with the surrounding joists, in other words flat, not necessarily level .

 

[raferguson]

The suggestion to "sister" the joist, put a new joist right next to the old one, is a good one. If desired, you could bolt the two joints together, but even nailing might be good enough.

As far as how far to jack it, I suggest that you put a level upstairs, and let the level be your guide. I saw some pros jacking up a house that had a low corner, and they had a sophisticated electronic level on the floor of the house. They jacked a little, and then waited after jacking, because sometimes it settles a bit. I would not be in a big rush in terms of how high to jack it, take your time, jack a little, let it sit and settle, then jack a little more. That is what the pros do.

However, if you are going to put in a new joist, you may have to jack it a bit higher to get the new joist in. But on the other hand, newer beams are a bit smaller than old beams, I suspect, so that might not be an issue

 

[larry4406]

Rather than a single side scab repair, consider 3/4" plywood scabs applied to each side. Repairs I have done have been 4' or 8' plywood rips centered on the defect (engineer spec'd the scabs). Two plies of 3/4 gets you back to the same cross-section you had with a 2x (assuming you rip it to full depth) with equal strength either side of the joist so it deflects in plane vs rolls.

In my house, the prior owner vandalized many of the joists for plumbing and HVAC. I used 8' scabs centered on the defect. Jacked up and proved straight via chalk line, applied construction adhesive, applied plywood scab, nail 3 rows 4" o/c both sides. Released jack after scabbing and chalk line stayed straight. I had damaged 2x10's.

 

[rlitman]

Dont jack it up 'till it closes'. It might not close, and you could hose other things in the home...

+1 The wood probably shrank as it split.

I'd use a 6' level to jack it until it is straight, and then glue and nail in a sister that is at least 4' long.

 

[shedfullatools]

Jack it level, sister another piece of dimensional lumber to it (glue and screw) and make sure you run it as close to the full length (if not the full length if you can get it in) as possible.

This but use nails instead of screws, or at least a mixture of both. Screws have less shear strength than nails and like to snap.

 

[matt_i]

What I see is a "header" that transfers loads into that joist from two others. Knot right at that same area is a bad luck coincidence.

I would back up that connection with a Simpson tie of appropriate depth, I would use their hex head screws with an impact driver over trying to drive nails into a knot. Hopefully there is room on the back side of the joist near the wall...

Next I would sister the outside (where a long timber appears to be able to fit) with 2x material, hopefully the wiring staples can be removed and there is enough slack so it can be restapled back.

My choice would be the Loctite PL 8X construction adhesive applied in sort of an X pattern. I would use at minimum a 2x (10 or 12) SPF, better yet if you can find Southern Yellow Pine (SYP) and best would be a piece of 1-3/4" wide LVL. I would use the GRK-RSS screws 5/16 x 3-1/8" in a pattern about 1 thickness away from both the upper and lower edge. Probably every 10" or so, staggering upper and lower alignment. Clamp the faces across

As far as jacking, as above I would go slowly and see if the crack closes easily. I wouldn't be hell bent on getting it tightly fitted again, its possible the wood fibers are gnarled, swollen or twisted and won't close back up perfectly cleanly any more. If you can get some construction adhesive into the crack, poked with something like the end of a tie-wrap or scrap piece of solid copper wire, also good.

 

[bob15]

I would use construction adhesive, but I'm not sure if i would use nails or screws....I would (and have used) hex bolts or carriage bolts and/or TimberLok lags.

 

[blair683]

Thank you guys for all the ideas and tips of how to repair. I don't know what I'd do without this forum.

 

[The Cobbler]

actually an easier approach would be to jack it up and put a 4x4 under the crack

 

[blair683]

I though about that as well. I'd rather not have a post/jack where the crack is though. It would be in the way.

 

[TractorJeff]

Broke in a knot due to old age and modern appliances.
Sister it as suggested and sleep tight!

 

[Kaizen]

No big deal. I have had the same issue. As my basement is low overhead I didn't want to have it any lower then the 2x6 rough lumber. So I cut 3/4 plywood and sisters it with that. I did jack with bottle jack and 6x6. Also put gorilla glue in the crack. Screw it with self drilling deck screws like deck mate. I repeated the fix on a few more to stiffen up the floor. Ten years later still perfect.


Sent from my iPhone using Tapatalk

 

[1949 caddyman]

Broke at a knot.

 

[ItsNemo]

This but use nails instead of screws, or at least a mixture of both. Screws have less shear strength than nails and like to snap.

True...the advantage of screws is they draw everything together tight so the glue can do it's job. Use structural screws if you're really feeling it.

 

[yeldogt]

I think it cracked due to the large knots ,, and it's also being used to head off the other joists. Today that would have been a doubled up nailed 2x.

Level it up, especially if the refrigerator is directly above ......If you can get a full length matching 2x in place on the one side you would strengthen the whole assembly. That would be ideal -- use a shorter 4' section on the other side to bridge the crack .... angel two trough bolts on each side about 1' back from the crack through all three 2x's. Use some glue and nail the rest to hold together.

If it was not headed off -- two 4' 2x on either side with bolts would be a typical fix. They do that all the time with termite damage are me.

 

[theoldwizard1]

EDIT: FLITCH plates ! End of discussion.


Segue - At my son's house (built in the late 50s/early 60s; bought as a repossession during the Recession) he did a major remodel of the main bathroom, going down to the studs and the floor joists. When they pulled the tub and the partially rotten 3/4" plywood up under it, one of the joist was rotten more than 1/2 through ! My guess was water would leak past the sliding shower door on the tub and down on top the floor. Floor covering was sheet vinyl so it easily got underneath that. The rest is history.

There was no way to get a new joist (2x10?) between the 2 block wall supporting structure, so when we sistered a slightly shorter new one on, and a non-load bearing wall because a "partially" load bearing wall ! Lots of construction adhesive and through bolts.

 

[ard]

You guys are killing me...F L I T C H plate.



https://en.wikipedia.org/wiki/Flitch_beam

Edit: fish plates stink



(And not picking on any one person- it was mentioned twice....)

 

[Lelandwelds]

Old houses are never straight, square, or level. Nail and then bolt a 2x on either side. Forget the glue. Old houses like to move. Go easy with the jack. Consider a screw jack with half a turn a day if the load is high.

I'd just bottle jack it, sister on one or both. Drive four nails with a nailgun, drill pilots, and carriage or lag bolt it up and forget it.

Or just forget about it for the next sixty years. House wont fall down over one split 2x. Thats just old house "character".

 

[rburke65]

Fish plates....funny. I had fish today!

 

[6768rogues]

Get a new similarly sized board, as long as you can get in place. Look down its edge to determine which direction it has a crown, that will be the edge that goes up.
Put the new one beside the old one. Jack up the old one till it is matching the new one or as close as you can get. If the other parallel ones are sagged, you might only be able to match them. Through bolt and nut it staggered high and low over its length, away from the crack. Glue won't hurt, too.
If it sags back substantially when you take the jack out, you could put a permanent post under it.
I don't use fish plates because they are typically not very long and the bolts will stretch the bolt holes in the wood without much plate length.

 

[MikeF2316]

I'd monitor it for a couple of months, see if gets worse. It may have been like that for years.

 

[Boomer343]

If I wanted to stabilize it I would use Titebond III glue with 3/4 exterior grade fir plywood on either side bolted in an M pattern with 1/4" bolts. Joist would need to be rough sanded.

If it has sagged or needs lifting I would cut the joist then use 1/4" steel plates either side with a piece of channel welded to the plates along the bottom of the joist. Put the metal in place, lift the joist to position and use 1/4 bolts.

Screws and nails will only cause more splitting of that old hard wood. Been there done that. 100 year old douglas fir gets nasty

 

[blair683]

Thanks for all the tips everybody. I will post an update once I make the repair.

 

[coljar]

Lots of good advice and really an easy fix compared to one I had a few years ago. I had bought a house for use as a rental and the whole floor over the cellar had a very pronounced sag with a couple of cracked joist. I tore the whole floor over it up and replaced all the joists. You might paint it after you're done. I imagine you will fix it right, but any repair like that sticks out like a sore thumb.

 

[CTyankee]

Hard to tell from the picture, but it looks like the joist is also helping carry some of the load of the 3(?) joists headed off against the chimney. If you intend to try and jack up the joist, you should also add support under the end joist against the chimney. A few studs could be permanently placed under that joist to help support their load and not infringe on the space.

Lots of way to address the broken joist have already been mentioned. The joist looks like it broke on a butterfly knot. It should have been culled, or at the least, not used in the place it was.

JMO.

 

[NUTTSGT]

Thanks for all the tips everybody. I will post an update once I make the repair.

Make sure you stop as you do the repair and post up some pictures for future reference.

You have plenty of advice so I really don't have to say sister it, glue it & screw it.

 

[CraigStu]

... Go easy with the jack. Consider a screw jack with half a turn a day if the load is high.
I'd just bottle jack it, sister on one or both. Drive four nails with a nailgun, drill pilots, and carriage or lag bolt it up and forget it.

The slow jacking is key. you are looking at one piece of wood but there are a lot of other pieces that have also moved. They moved slowly and best that they go back slowly. With the hardness of the existing joist in mind, I really like the idea of carriage bolts. I would jack it w/ a 2 ft piece of 4x4 under it. Since it is actual dimension lumber the modern equivalent w/ be 1/2 inch under sized so should still be able to be installed. I also like the idea of plywood. You could get high end plywood to more closely match the hardness of the joist.

 

[NWOhioChevyGuy]

Similar issue in my 1880's farm house when I bought it.

6' long 2x8's glued and carriage bolted on, been 10 years and still as I repaired her!

 

[Ntolerance]

Sorry to hi jack but I have a similar issue. Hopefully the pic comes out ok on Tapatalk

I have two low joists. Seen here in the pic. If you look at the header of this non load bearing rough in you can see the 2x4 is bowed. No damage or cracks on the joists.



Second pic is looking at the rough in from the opposite side. Those beams are 10x10. The posts are 10x10. In between the span pictured is another 10x10 post on the upper floor. That post has moved down about an inch. I haven't measured to see if the upstairs post is on the beam or the joists but my gut tells me it's on the joists that have dropped down. But the upstairs beam goes all the way to the roof and it's in the center of the roof peak. I suppose the peak could be offset from the house center.
The joists are 3x10.



I'm thinking I need to slowly raise that lowered joist area up and use this rough in as loadbearing. Not in its present form obviously. But I would like to hear thoughts from the group.

I have also noticed the concrete has settled in this same area to maybe everything has dropped down ?

Sent from my iPhone using Tapatalk

 

[Boomer343]

Sorry to hi jack but I have a similar issue. Hopefully the pic comes out ok on Tapatalk

I have two low joists. Seen here in the pic. If you look at the header of this non load bearing rough in you can see the 2x4 is bowed. No damage or cracks on the joists.



Second pic is looking at the rough in from the opposite side. Those beams are 10x10. The posts are 10x10. In between the span pictured is another 10x10 post on the upper floor. That post has moved down about an inch. I haven't measured to see if the upstairs post is on the beam or the joists but my gut tells me it's on the joists that have dropped down. But the upstairs beam goes all the way to the roof and it's in the center of the roof peak. I suppose the peak could be offset from the house center.
The joists are 3x10.



I'm thinking I need to slowly raise that lowered joist area up and use this rough in as loadbearing. Not in its present form obviously. But I would like to hear thoughts from the group.

I have also noticed the concrete has settled in this same area to maybe everything has dropped down ?

Sent from my iPhone using Tapatalk

Looks like your point loads don't match up .... also the point loads should terminate on a concrete footing that is on undisturbed soil not the floating floor pad. You may be in for some heavy and expensive remediation.

 

[metalmagpie]

To the OP: Put your wife on a diet! LOL