Lavatory drain path to avoid beam

[FLWmimic]

Hi, First time poster, lots of time lurker here.

I have a mudroom lavatory over a suspended concrete slab (new construction). Unfortunately, the 1 1/2" drain landed directly over one of the integral 5" W X 11" D beams. The 4" slab (over 7" polystyrene formwork) has already been poured. I just now realized that my sub used a 90 elbow/4-6" chunk of pipe/90 elbow combination to avoid the beam (I can't tell whether they are long-sweep 90s). It's all over a storage area of the basement.

I would have used a couple of 45s. Function & building-it-right are my first priorities. However, I am a novice, an owner-builder, and I am the first to admit that I don't know best. On the other hand, I'm a farm girl: this mudroom will be USED, and I don't want it to get clogged!

Should I go to the time, bone-jarring effort and eternal concrete dust to correct this (if I even can)? I will be renting a 3" core drill this next week (to fix other problems this sub created), so now is the time to do this if I should. However, I need you experts to tell me whether I should based on benefits/costs analysis. I admit that I'm anal, so is this really a problem, or not?

Thanks in advance for any advice.

 

[Terry]

Can you post a picture of what is there now? 800 pixels or less and an attachment.

Normally from vertical to horizontal, a long sweep. From horizontal to vertical a medium sweep.
If this is what you have I would leave it. And yes, the 45's are better.

 

[Sponsor]

 

[FLWmimic]

Can you post a picture of what is there now? 800 pixels or less and an attachment.

Normally from vertical to horizontal, a long sweep. From horizontal to vertical a medium sweep.
If this is what you have I would leave it. And yes, the 45's are better.

 

[FLWmimic]

Can you post a picture of what is there now? 800 pixels or less and an attachment.

Normally from vertical to horizontal, a long sweep. From horizontal to vertical a medium sweep.
If this is what you have I would leave it. And yes, the 45's are better.

Sorry, it's impossible to take a pic because it's all hidden in the floor system unless/until I cut the foam away. However, I'm attaching a schematic of what I diagrammed out to replace it w/45s. Just picture that he used the 90/pipe/90 combo instead of where I drew the 45s. This is why I also can't tell what sweeps he used, although I would like to assume that he used the proper ones since he is a licensed plumber. Hope this helps.

 

[Sylvan]

I also like follow decent plumbing codes which require a long sweep on drainage under 3"


What you can try rather then tearing anything up is try to snake the line and see if the cable can easily pass the fittings installed


Also in the future tell the plumber in case they not have common decency to install under ground piping NO LESS then 2" as codes set up minimum requirements

 

[FLWmimic]

I also like follow decent plumbing codes which require a long sweep on drainage under 3"


What you can try rather then tearing anything up is try to snake the line and see if the cable can easily pass the fittings installed


Also in the future tell the plumber in case they not have common decency to install under ground piping NO LESS then 2" as codes set up minimum requirements

Thanks for the idea. I currently don't have a snake (I planned to do the electrical & sub out the plumbing), so I tried to pass my fish tape through- it wouldn't pass. I don't know if this is similar to a snake, or if a snake would be more flexible.
Currently, it's just the stub out passing between the floors- no additional pipe is connected.

RE the last, well, suffice to say this plumber will no longer be working on the remainder of my project (and no, I didn't hire the cheapest guy; I interviewed 10 plumbers, got references, and hired the only one who had had any experience w/ICF).

 

[wwhitney]

What does the current drain do after it penetrates the slab?

Will there be a vanity that would hide the drain pipe if it kicked out of the stud wall (with 45s) above the slab level? If you have a 3" core drill, it wouldn't be hard to core drill the slab in the 4" section and replumb the drain that way. [Assuming you know where all the reinforcement is.] The way you've drawn it would be harder to do, as you have fittings within the slab, I think you'd have to make a bigger hole and then patch the slab.

Cheers, Wayne

 

[FLWmimic]

What does the current drain do after it penetrates the slab?

Will there be a vanity that would hide the drain pipe if it kicked out of the stud wall (with 45s) above the slab level? If you have a 3" core drill, it wouldn't be hard to core drill the slab in the 4" section and replumb the drain that way. [Assuming you know where all the reinforcement is.] The way you've drawn it would be harder to do, as you have fittings within the slab, I think you'd have to make a bigger hole and then patch the slab.

Cheers, Wayne

This is why I love the ability to post to a community forum. . . brainstorming ideas that make you think of other possibilities, thanks! Although it was going to be a floating vanity, there may be possibilities on either side of the wall for this. I do not know exactly where the current drain was going, although I (again, as a novice) can see 2 possibilities. It does drain into a storage area where I am not concerned about pipes crisscrossing & showing beneath the ceiling (no wall directly beneath). When I'm home this evening I'll pencil out a couple of follow-ups to your idea to see what you think.

I also had the idea of using the 2" vent penetration he placed 6" away in the same wall (same 90/pipe/90 construct, but 2") as the drain. I believe this penetration is for the combined basement vents, but I think I have figured out a different way to rout those if necessary.

 

[FLWmimic]

This is why I love the ability to post to a community forum. . . brainstorming ideas that make you think of other possibilities, thanks! Although it was going to be a floating vanity, there may be possibilities on either side of the wall for this. I do not know exactly where the current drain was going, although I (again, as a novice) can see 2 possibilities. It does drain into a storage area where I am not concerned about pipes crisscrossing & showing beneath the ceiling (no wall directly beneath). When I'm home this evening I'll pencil out a couple of follow-ups to your idea to see what you think.

I also had the idea of using the 2" vent penetration he placed 6" away in the same wall (same 90/pipe/90 construct, but 2") as the drain. I believe this penetration is for the combined basement vents, but I think I have figured out a different way to rout those if necessary.

What does the current drain do after it penetrates the slab?

Will there be a vanity that would hide the drain pipe if it kicked out of the stud wall (with 45s) above the slab level? If you have a 3" core drill, it wouldn't be hard to core drill the slab in the 4" section and replumb the drain that way. [Assuming you know where all the reinforcement is.] The way you've drawn it would be harder to do, as you have fittings within the slab, I think you'd have to make a bigger hole and then patch the slab.

Cheers, Wayne

Above all, your comment about where the drain goes made me realize that it will need to turn another 90 or 45/45 since there is no wall directly beneath it. That would make 3 90s in a row. Therefore, I really need to fix this.

If the first thing I try doesn't work, I am going to kick it out of the stud wall on the side where it will come out under a bench (per your suggestion) and core drill a new hole.

Thanks to everyone for taking the time to respond and give me helpful info!

 

[Sylvan]

Good luck

 

[Tuttles Revenge]

We work with floating vanities a lot. I devised a box that sits underneath but is just 4" out from the wall floor to bottom of the cabinet. It can hide stuff but still gives the appearance of that floating box.