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Discussion Starter #1
I sistered a new joist to an old one that I had to cut a 1 1/2 ft section out of the middle, 2x10x12 joists. I'm curious if I need to toenail the ends of the new joist into the ledger/beam. Anyone have an idea about this?
 

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Preferably, the new joist should bear in the same fashion as the old one. If the old one beared on a sill plate, the new one should also. If the old one was toenailed or end nailed into a ledger, don't repeat that! Use a joist hanger or a beefy corner bracket.
if you sistered onto a joist that had 1-1/2 feet removed from its midspan, then that old joist is no longer a joist, it is a non-functional hunk of lumber. The old joist could be removed if you like.
 

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Ok thanks, old joist is toenailed in, I'll get a new bracket for the new one. I gyess it is just a piece of dead weight now. I will prob just leave it in for a little extra real estate for the subfloor. Also, I notxhed the ends by a 1/4 inch in order to roll them up there. Ive seen where its a good idea to drill a hole at the corner of the notch where the horizontal and vertical edges meet, in order to help prevent splitting. Do you know if this is necessary on a 1/4 inch notch?
 

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I have never seen any data that would lead me to believe that stop-drilling is effective with wood, to arrest an existing crack or prevent a new one. Wood is made of fibers and you weaken it by cutting more fibers. It is smart to try not to overcut a notch in wood in the first place.
Any time you notch lumber, the joist (at least locally around the notch) is only as strong as the dimension of the remaining material. It is not so bad to notch near the end, where the bending stress is less. Notching near the midspan is a no-no.
The stop-drilling method you mention is definitely effective with aluminum and other metals, however.
 

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I notched the bottom and put a steel shim in
Our engineers would love that. :sad: but if you left the old one and nailed them together, there won't be a lot of stress on that. Assuming the old one has good bearing.
 

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retired framer
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Ok thanks, old joist is toenailed in, I'll get a new bracket for the new one. I gyess it is just a piece of dead weight now. I will prob just leave it in for a little extra real estate for the subfloor. Also, I notxhed the ends by a 1/4 inch in order to roll them up there. Ive seen where its a good idea to drill a hole at the corner of the notch where the horizontal and vertical edges meet, in order to help prevent splitting. Do you know if this is necessary on a 1/4 inch notch?
If you are stopping a crack in sheet metal, it is standard to drill a hole to relieve the stress, they do that on airplanes.
Not so much with wood, the grain still works against you.

In this picture you can see that the notch made the joist actually half what it should be and when it flexes, it works on the grain of the wood and splits at the weakest spot and it appears that it went right thru the hole that was drilled there. The fix for it would be to just add plywood to the sides to join it back up or wrap a hanger around it to support the bottom.



 

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Discussion Starter #10
Ok well good to hear, I figure if it splits its going to be that last quarter inch so not a big deal. And I can fix that. Also old joist is bearing just fine at the ends so going to leave it. It did shrink in its 40+ years of life, thats why I had to notch. Was measuring a hair under 9 inches, and new joist was 9 1/4.
 

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Ok well good to hear, I figure if it splits its going to be that last quarter inch so not a big deal. And I can fix that. Also old joist is bearing just fine at the ends so going to leave it. It did shrink in its 40+ years of life, thats why I had to notch. Was measuring a hair under 9 inches, and new joist was 9 1/4.
The engineers her would prefer us just cut it down to match and if we are leaving the old in place we put a small angle to that cut so it will roll up easier. If the floor is nailed to the old one non of the small details at the top matter. But you will be fine.
 
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