[Seabrook1983$]

Moving the plumbing on a kitchen sink in a 70 year old house, in 2” PVC. In getting from sink to drain/sewer, it’s a long-ish run and I’m confronted by a load-bearing beam that I cannot go over (on top of). There’s a couple of feet drop on the sink side, and a couple more on the drain/sewer side. Is it practicable to make a “U” out of four 90-degree elbows and pipe, and go under it? Isn’t that just an oversized P-trap? Presumably I’d want to incorporate a clean-out as part of this.

 

[jmon]

imo, I would not use the 4 90 degree elbows.

You can run right through the joist/beam as long as it doesn't exceed 1/3rd of the joists depth. I see it all the time.

 

[Nealtw]

Go below the bean and stay below the beam height.

 

[Seabrook1983$]

Seems like I might have some though choices.

imo, I would not use the 4 90 degree elbows.

Funny, I was downstairs and noticed I had done something similar, with somewhat less drop, elsewhere in the plumbing perhaps 15 years ago. No problems, but...lain:

You can run right through the joist/beam as long as it doesn't exceed 1/3rd of the joists depth. I see it all the time.

Oh, boy, I just burned out a couple of Milwaukee hole saws cutting 2-1/4"holes earlier in the project. :crying:

Go below the beam and stay below the beam height.

Cannot. Where I tie in needs to be several inches above that. THEN it drops.

 

[TheEplumber]

Drain lines drop at 1/4" per ft. It is never acceptable to reverse grade a drain line. Once you go under the beam, you must continue sloping down...

Sent from my SM-G970U using Tapatalk

 

[Old Thomas]

If you create another trap you need to think about how venting will work. If you have two traps inline the first trap seal will prevent the second one from venting and it will probably burp and gurgle and drain poorly.

 

[Seabrook1983$]

If you create another trap you need to think about how venting will work. If you have two traps inline the first trap seal will prevent the second one from venting and it will probably burp and gurgle and drain poorly.

Interesting and valuable comment. Under the sink, after the P-trap, I had installed one of those one-way air-inlet valves that substitute for a through-roof vent. Maybe enough? Maybe not?

Well, I spent time working on another part of the project while I mulled it over. I have one fresh hole-saw blade left, and am considering trying to bore through the three 2x12's. Ugh!

 

[SeniorSitizen]

Burning out hole saws indicate too much rpm. A brand name saw will cut for longer than you can in a day. To prevent excess heat try backing the saw out frequently to clear the chips.

 

[Missouri Bound]

I have one fresh hole-saw blade left, and am considering trying to bore through the three 2x12's. Ugh!

If you have a good quality hole saw it should cut like butter.
Or you can rent or borrow a Hole-Hawg with the screw pilots. They pull through the wood. Of course you have to stop every 1 1/2" to clean out the saw.

 

[Nealtw]

What are the rules there about drilling beams, it wouldn't happen here.

 

[Seabrook1983$]

What are the rules there about drilling beams, it wouldn't happen here.

Well, change of plans. Trying to decide where to bore, once through I'm into a very crowded are with lots of pipes (Including, as it's right near the boiler, a lot of pipe leading to radiators - plumbed in inexpertly by me 30 years ago). No way to lead to where I wanted to tap in to a 2" line without going uphill somewhere.

That leaves where the 3" drain/sewer pipe leads out through the wall to outdoors (sewer line), and as the house originally did not have a basement, not all that far below grade. Standing in the basement, the line turns 90 degrees and leaves the house horizontally at chest level. Enough connections/fittings so that tapping into THAT line is tough.

I was shopping on-line, saw "Saddle Tees" to tap into a 3" line. Oddly, the descriptions kept saying for 3" or 4" lines, how could that be. Just went to Lowe's and Home Depot, which I did not want to do. Turns out those were not in stock anyway, I wanted to measure to ensure fit. No go. I liked the ones that you glued in place PLUS U-bolts to secure.

Well, I decided on the scary way - scary for me. Bought a 3"x3"x2" Tee, with the 2" entry slanted. I have barely enough to cut into the vertical 3" line between two fittings, with about an inch left over. I have ONE chance to get this right.

Working up enough nerve to cut. If I get it right, the rest of the run is simpler, I go below that beam and have plenty of room for the correct "drop" of the run. Wish me luck!

 

[Seabrook1983$]

Burning out hole saws indicate too much rpm. A brand name saw will cut for longer than you can in a day.

If you have a good quality hole saw it should cut like butter.

Milwaukee 1/2" hole electric drill, Milwaukee hole saw. RPM's should have been low enough (??? it turns much slower than the Milwaukee 3/8" drill), not sure what a better quality hole saw would have been.

 

[Seabrook1983$]

Well, I decided on the scary way - scary for me. Bought a 3"x3"x2" Tee, with the 2" entry slanted. I have barely enough to cut into the vertical 3" line between two fittings, with about an inch left over. I have ONE chance to get this right.

Working up enough nerve to cut. If I get it right, the rest of the run is simpler, I go below that beam and have plenty of room for the correct "drop" of the run. Wish me luck!

SUCCESS! The line I tapped into serviced a toilet, and after the cutting and the gluing, it passed a flush test w/out a leak.:smile: I now have a place to feed in a 2" line from the sink about 2 feet lower than before, so the beam is no longer a challenge to be met.

Thanks, all, for the input!

 

[Seabrook1983$]

I forgot to report back... All done (well, the plumbing anyway, not the rest of the project), all is working well now. I'm perhaps a wee bit better than minimum slope, I wish there had been opportunity for more.