joist crack repair question

hoping someone can answer this.

i have a few 2x10 joists that have horizontal cracks.

each joist has only one crack.

they all appear to originate from where the nails went in to secure the joist to the joist hanger.

these joists also have bridging in the center span.

my question is, if these cracks are stable over years and have not grown in length. is it safe to presume they were from the original construction, and not from being stressed ? (ie. heavy loads on top).

the other question is, if the crack originates from the end, where it's resting on the hanger, wouldn't a load on top, tend to compress the crack together ? (since the hanger is providing some resistance from the bottom of the joist).

and thirdly, what does "sistering" the joist actually do ? it would seem to be futile, since the sistered joist, would need to be in a hanger too to support the weight wouldn't it ? (i don't see how just lag bolting another 2x8, 2x10 next to an existing joist is going to help that joist bear any loads that are vertical - since the sister joist isn't resting on anything - just lag bolts - and the forces are still transmitted to the existing joist hanger of the existing joist).

thanks in advance for any responses.

basically i'm wondering if i should worry about those cracks or not - they are stable, and have not changed in size. the joists in question are also sorrounded by doubled up 2x10 joists, 16" away.

Reply to
Joe
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Well Joe, I think you worry too much. It is very common to run into

2x10's and 12's with splits on the ends, especially douglas fir joists. Not that I like it, but you just have to use them and it has always turned out fine. There are probably several reason the crack doesn't compress together. First, there isn't THAT much weight on any given joist. Second, the joist usually doesn't wind up resting on the bottom of the joist hangar--it shrinks up off of the joist hangar and is actually held by the joist hangar nails working in shear. Sistering can make sense if you are looking for a stiffer floor, for example. I'd guess it is best to have the sister supported on its own (by a ledger or maybe a new double hangar that goes over both joists) However, it may be that the joist hangar on the orginal joist has plenty of capacity.

Are your floors real bouncy? If they are, there is a small chance the splits are something to be concerned about. But if you have no other indications that your floors are underframed, I wouldn't worry about it.

Reply to
marson

thank you for the replying.

yes, they *are* douglas fir joists.

no , there is absolutely no bounciness at all. the floor is rock solid.

i guess i won't worry about it, but i marked the end of the crack with a pen, just in case (to monitor if it grows). it's been stable for years, so i think you're right. it's probably nothing to worry about.

Reply to
Joe

Reply to
jloomis

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