The Making of a Master Suite

[ss3964spd]

If it is LB you should be able to trace the load path straight down to a load bearing structure; foundation walls, support beam, etc. That of course assumes it was built right. LB interior walls will, in my mind, also be perpendicular to the joists above.

Glad your floor came up without too much of a fight. I just demo'd my guest bath this weekend, I wasn't as lucky.

[MTy]

So I've got a bit of a problem. Pulled up some of my subfloor(all of it will eventually go) to see what the toilet plumbing is like since depending on what I can do with the toilet will determine my final bath layout.

I'm over on Terry Love getting help with moving the toilet but either way I a going to have to remove some of the waste line and sister the joist to the left of the toilet flange.

1. It is my understanding is I can sister at 2/3rds or more of the joist and not have to sister all of the way? There are some copper supplies I'd like not to have to mess with about 12 inches from one of the walls. Total span is 9ft from load bearing wall to load bearing wall.

[cx]

Originally Posted by Eric

1. It is my understanding is I can sister at 2/3rds or more of the joist and not have to sister all of the way?

I think there is some misunderstanding there, Eric. The only equation I'm aware of involving sistering of floor joists is that if you're sistering for the purpose of reducing deflection, the absolute minimum length you must sister is the center 2/3rds of the unsupported span of the joist.

You've got a bad situation there. I see no way that sistering as a repair will do any good at all in that situation. I can't tell for sure in your photo, but it appears the joist might have been cut away all the way though the bottom below those pipes. Is that the case?

[MTy]

No its not all the way through. There is about 2 inches top and bottom. Would sistering work if I sistered the full length from load wall to load wall? Or maybe blocking and hangers to neighboring joist?

[cx]

What size are those joists, Eric? I can't find reference to that in the thread.

[MTy]

Thanks CX, thought I had mentioned that. Joist are nominal 2x10, 16" on center, with a 9 ft. Span. Besides the cutouts they are in good shape, no knots ect.

[cx]

Eric, if you'll look in our Liberry you'll find a thread for Lumber Notching and Boring Guides. Either of the links in there will be helpful in diagnosing the problem you've got

The maximum hole you can bore in a nominal 2x10 floor joist is 3 inches. The minimum wood that must remain from the top or bottom of the joist to a bored hole is 2 inches.

If you meet those guidelines, your joist is considered whole. If you don't, you would need to correct the deficiency.

Viewing your photo, it's gonna be difficult to correct what you've got even with the correct method of "headering off" the deficient joist as would be done in new construction. There's always a way, but the only way plumbers know is to chop away whatever wood is in the way of their pipes. And they're generally not sufficiently careful to cut a hole in the joist rather than just notching it or chopping it off completely.

Without being able to see the rest of your floor and plumbing there's not much I could suggest. If you think you meet the guidelines, or think you're close enough for your comfort level, you can, of course, move on with what you've got.

My opinion; worth price charged.