Leveling/strengthening floors (basement ceiling)

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Old 07-30-15, 05:47 AM
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Leveling/strengthening floors (basement ceiling)

I have an 1880s house with sagging floors due to the following;
1) Flooding basement allowed tree-trunk support columns to rot and sink.
2) Previous owners completely removed a stairway going into the basement (including all support posts)
3) Brick chimney was left, despite fireplace and supporting structure being removed.

I have regraded the yard to alleviate the flooding issues and removed the chimney. Now that the causes are gone, I'm trying to remove symptoms as well and am leveling out the floor.

I'm doing just the stairway area first because it is a smaller area and sagging the most. While jacking things up and trying to determine where more support might be needed, I noticed the following joist.

The picture is of a true 6x9 going from the exterior wall of the foundation to the main beam. As with all the other joists, it is notched so that the top half rests on the main beam and the rest just hangs. There is a sizable crack on one side about a foot long that does not extend all the way through. How can this be secured?

Most other joists are true two inches wide. Does anyone know where I can get joist hangers for them (or can anyone state that I do not really need them)?

Crack on west side of joist. Black wire is just a coax cable (no tension).
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No crack on east side of joist
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Thank you,
 
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Old 07-30-15, 06:57 AM
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Since you lost all the original support, I would build some headers with some adjustable lally columns. Try to sister the cracked joist if you have room. I have no experience using self levelers so I can't comment, on that
 
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Old 07-30-15, 07:08 AM
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I'm already using columns and headers to level out the former stair area.

Is full sistering necessary for that crack or would a decent joist hanger take care of that?

I'm not sure I can even sister. The non-damaged side provides the access I need, but the damaged side is where all the joists (running parallel to the main beam) from the stair area are hung.
 
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Old 07-30-15, 08:24 AM
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I don't know what you mean by full sistering. However, sistering a joist the entire length is the only way to do it. A joist hanger isn't a replacement for sistering. However, you may not need to do either one. A header in that spot is all you need as far as I can see. Also, it wouldn't matter which side you install the joist. If you sister it, do it wherever you have the room.
 
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Old 07-30-15, 10:31 AM
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I did mean "if it had to go the entire length". My limited understanding of sistering is that it's there to provide extra support for an undersized rafter. This particular rafter is not undersized, it is just damaged in one area.

Since both the rafter and main beam are of sufficient size, it seems to me that I could just use a column directly under the damaged area under the rafter where it ties into the beam. If that is true, then I would also think that a rafter tie would work as well. But, that's a lot of assumptions on my part and relies on being able to find a six inch wide rafter tie.
 
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Old 07-30-15, 11:02 AM
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Simpson U610R might be the right size joist hanger for such a beam. LU26R would be a full 2" wide for rough lumber joists. (2x6-2x8) or U210R (2x10-2x12) Finding them might be a problem. Amazon or some other online source is probably your best bet and most convenient. Just google the hanger numbers you need. The "R" denotes rough lumber, meaning the hanger will be a full 2" wide. Here is a link to that page of their catalog.

I would caution you to be very careful about jacking too much. Don't think you can raise in 5 minutes what took 135 years to sag. Often when you jack something up, all you will do is pull the nails out on the other end or break something from all the pressure. You also don't usually want to truly "level" the framing. That's probably impossible in a house that old and you will probably break something or create bulges in the framing if you jack things up to "level".

"Rafters" are generally in a roof. "Joists" are in a floor or ceiling. Its not surprising that the cross beam cracked near the notch, that would be the weakest point. Notching a beam almost cuts it's holding power in half because of the tendency for splitting to occur.

For the photo with the crack, I wouldn't be afraid to slowly jack that up, making sure that as you jack that it's not just bending or doing something unforeseen to the rest of the framing... then install the U610R joist hanger mentioned earlier. Be sure you use the correct nails with it. Those nails have to carry ALL the load. Putting a permanent column under the intersection of those 2 beams would be advisable.
 
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Old 07-30-15, 11:40 AM
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I'm taking my jacking quite slow. So far, it hasn't even been noticeable.

Thanks for the correct on rafters and joists. It make my web searching easier when I use the correct terms.

As much as I want to make everything level, I know it's a pipe dream. My main goal to to at least make it so the middle of the house isn't sagging three inches and I can actually open the french doors.
 
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Old 07-30-15, 01:27 PM
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Once you get the desired height so you can open the French doors, a couple of headers with adjustable lally columns are all you need. I see no reason to add joist hangers & no reason to sister the cracked joist.
 
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Old 07-31-15, 09:32 AM
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All right. Thanks. Now I just need to spend the time getting it to the correct height.
 
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