Relocating Soffit Waste Line

[Cduffie2]

Back again with a new (old) house with new (old) problems! Lot's of back story here I'll save for another time but the short version —

We took down the kitchen soffit to replace some leaking galvanized pipes, and now we're replacing all of the galvanized in the house. Now we're wondering if we can move the waste line that was in the soffit, up into the joists. Joists are 2x7, 16" on center.

We removed about 3" of drypack from the bathroom floor above the kitchen so the finished floor height is about 3-3/4" above the top of the joists. Plumber who is replacing the supply lines said that we could sister the joists upstairs with 10" joists — and then drill the 4" hole for the waste line through the joists to get it above the kitchen ceiling. Was also thinking we could put joist supports on as well for additional support.

Is this even possible or advisable or should we just get used to the idea of having the soffit in the kitchen?

 

[Breplum]

Max hole in a 2 x 12 is 3-3/4" in the outer ends of joists.
I am aware of joist repair hole reinforcer supports for 3" pipe from Metwood at over $50 each. for 2x8"

 

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[John Gayewski]

Since you're renovation seems petty extensive have you thought about moving the toilet to a better location? Better is relative I guess. I mean move the location of the toilet so it can be routed in a way that allows you to have the kitchen you want.

 

[Cduffie2]

Unfortunately moving the toilet isn't really in the cards right now — and not even sure there's a great spot to move it to that would solve the issue. But curious if there's something specific you imagined seeing the pictures?

 

[John Gayewski]

Is there a basement? It seems you could either move the toilet over so it's not in front of the window so it can drain next to the window and into the basement to be rerouted. Or over to the same wall as the riser where you could notch and repair (possibly) one joist. There's also the possibility of furring a wall or further to gain some space for piping on that rise wall.

The main problem seems that the toilet was not planned or routed well to begin with, lol.

 

[Jeff H Young]

I dont want you to give up on removing the soffit but I think it easily could be smaller.
What about bringing the 4 inch up another wall that is in the correct joist bay ? or even 2 stacks from below kitchen floor?
I havent done one of these in a while an exiciting job even with chalenges !
I cant get a full handle on the scope as far as structural reasons it wouldnt work with some changes.
BTW any info on the hardware you show image of to beef up hacked joists?

 

[Cduffie2]

A few more pictures in case that helps — and also took another look. Joists are actually 2x10. Spoke with the plumber today and he seems a bit "unsure" to say the least... when I asked, he said it was possible but when I asked about what size the joists would need to be or if there'd be enough room for the pitch of the waste line all I got was a "it'll be close".

Can anyone tell me, is there any way to rework what's here (ideally without putting another hole in the roof for a separate vent) to get the 4" waste line above the ceiling below?

Bracket is one I saw over at Skyline JoistRepair

 

[John Gayewski]

I never understand why people are worried about holes in their roof. We use boots all the time, like every single job we do, we don't have any issues with roof pennatrations or boots leaking. Drive around and look at every roof in the world with multiple multiple holes in them. They work great.

I believe I asked if you had a basement. You'd need to answer that so anyone who wants to help knows the potential options.

 

[Cduffie2]

Mainly worried about another hole in the roof because of many other projects that are underway, and lots of other concerns that aren't really necessary to put here. Plumber was also very hesitant to go that route for some reason.

Yes, there is a basement. I've attached a photo. Stack is on the left.

 

[Jeff H Young]

I got no fear bashing a hole in the roof LOl. the house is practically coming down to the ground and the hole in the roof is an obstacle I get it thats typical
You gotta crack a few eggs to make an omlett , 100,000 dollar remodel and worried about a 200 dollar roof patch. but the hole might or might not be issue , Id say forget about where the hole needs to be concider the entire job of where to bring new lines up and get rid of every bit of castiron and gal pipe . also concider the pipe size dont just copy what is there 3 inch likely is big enough

 

[John Gayewski]

I think unless you can route the stack next to the window, the only way you can leave your toilet where it is (and not have a soffit) is to have some carpenters rework your floor joist system. Building a pocket header would probably work, but it's major.