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speedball1 · Apr 20, 2009, 07:14 AM

Tom, there are situations where you have to make a connection under slab. What do you do in these cases in your area ?

Never in new construction! Most of the plumbing companys I've worked for are new construction or repair. I've never worked for a company that specialized in remodeling. I never liked remodel jobs. The demo always seemed dirty and with older homes you ran into problems with the older plumbing.
If we have a under slab leak in a residence that we have done we take up the slab,dig down to the leak, cut it out, solder in a new piece of copper, run a test, cover it up, patch the slab and hope like hell the inspector doesn't find out what we did. So far we've been lucky, that doesn't happen too often down here and all our repairs have held. I don't advise making joints under the slab if there's another way and if hobbzilla can get that hot and cold manifold moved over inside a wall he has the freedom to loop a feeder line to any fixture that he can't move over with the manifold. We both gave him viable options. Let's see what he decides. Regards, Tom

hobbzilla · Apr 21, 2009, 12:49 PM

Well I've been called a lot of things in my life: Hobbs, Hobb-knob, Hobbzilla, Ryan, Ryno, Ry-Ry, Rybo-Dybo, and zilla, but that might be my first "Hobb". :)

I just checked around and silver-soldering, since it is actually a weld, is an approved method of making a connection under the slab here in Dallas, TX. To add some additional concerns, I found out I do in fact have post-tension cables. And my shower manifold is about 1.5' from an exterior wall and have been told it is probably coming up through not just a 4" slab, but the outside pier which can be 2-3' deep and 2' or so wide...

I did a quick test on the manifold and from touch and sound, am fairly confident it only feeds the tub. I think I realize that no matter what, I will have to open the slab at least enough to cap off the lines.

My goals are:
1) First and foremost to protect the value of my home and keep it insurable. Therefore, I will get a permit and make sure it passes inspection.
2) Do as much work that I feel comfortable myself in order to stay within budget ($2k)
3) Leave the drain where it is at all design costs.
4) No platform or step-up shower.
5) Avoid creating a stagnent line to the shower. Since I don't know the source, the line will still contain water and can corrode the pipes and or be a heath concern.
6) Avoid silver-solder. Given that I do not have the experience, the equipment, and that although is code, can increase my odds of having a slab leak, silver-soldering is something I want to avoid.
7) Avoid running pipes on exterior walls. While I believe the garage is technically considered an exterior wall, I am confident any copper placed in that wall will not have a concern of freezing.
8) Work smarter, not harder. :)

So, my revised plan is as follows: I will crack open the slab to see where the initial run comes from and attempt to move the entire manifold as Tom suggests so it is no longer in the middle of the new shower. If I don't have the slack to move it, or if I damage the pipe, I am left with no other option but to silver-solder. I believe I would have to cap it will silver-solder, so I might as well just trench and extend the lines versus leave them stagnent _and_ capped. I think I can save some extra slab work by running the line to the tub through the shower curb if needed..

I have a plumbing contractor coming over to give me a quote and look at this today so I will see what he says.

Well, I'm back and in the thick of it. I wanted to write a few thousand words but I'll just post some pictures.

I have been informed by several people, that my idea for keeping the drain where it is based purely on my laziness. If that is the case, then since I already have to dig a trench for the drain, if worse comes to worse I will just run new lines to the tub in the drain trench.. Are there any issues with that?

As you can see, it does appear the manifold simply feeds the tub and nothing else. The tub has no manifold.

Also, is it a good sign or bad sign that the drain is already about 4" into the concrete and there is still concrete left to break up? I'm afraid I'm over a concrete beam being so close to the exterior wall.

Can the drain be run "in" the concrete? Or does it have to be run in the ground under the slab like the supply lines?

speedball1 · May 3, 2009, 04:40 AM

is it a good sign or bad sign that the drain is already about 4" into the concrete and there is still concrete left to break up? I'm afraid I'm over a concrete beam being so close to the exterior wall.
Can the drain be run "in" the concrete? Or does it have to be run in the ground under the slab like the supply lines?

You did say the job will be inspected, correct? And let me see if I understand,
You want to place a 90 on the old drain raiser, using the old trap and vent, and run a new drain line in the pour over to another 90 which would then stub up to pick up the new shower. Is this correct?
Since by doing this you are not only building a dog-leg in the drain line but also converting your "P" trap into a running trap,(see image).
I think I'd run that by the inspector first. What do you think? Regards, Tom

hobbzilla · May 3, 2009, 09:47 AM

Tom,

The jury is out on the inspection. I did contact the local gov't and apparently I need like 3 or 4 different permits (general, plumbing & electrical). With each running about $100 and the fact that I'm looking to be about $500 over my original budget... To make matters worse, the inspector had never heard of the schulter kerdi product and there is a good chance, unless kerdi was in the 2006 IPC code (doubtful) using standard drywall will be out of the question -- which means more $$ spent on cbu or similar. I am not sure how many inspections are required and at what stages they will need to be performed. No matter what, if I end up hiring a plumber, they (the plumber) will pull a permit regardless on that and if an inspector comes to look at that, I may get fined right then and there without the other permits pulled.

The city goes by the 2006 IPC code.

You want to place a 90 on the old drain raiser, using the old trap and vent, and run a new drain line in the pour over to another 90 which would then stub up to pick up the new shower. Is this correct?

I guess I don't know what I want to do yet. :) I was most definitely planning on using the existing vent and keepign the main drainage line that it is tied to now. Both the tub and the old shower's vent is halfway between them both on that exterior wall which didn't make the picture frame. I guess all of this will depend on several things:

1) Is it okay (code) to run a drain line in the pour? Or does it have to be in the ground under the slab?
2) How close to the stub does the p-trap have to be?
3) I am not opposed to opening up the current drain, taking out the trap and simply cutting and extending the line, creating a new p-trap where the new drain will be.

Thanks in advance for the assistance!

speedball1 · May 3, 2009, 11:39 AM

1) Is it okay (code) to run a drain line in the pour? Or does it have to be in the ground under the slab?

It's not good practice run your drain lines in the cement Instead of under it. I've seen floors that developed cracks after a while.

2) How close to the stub does the p-trap have to be?

Since it's not good plumbing practice to offset the trap, create a dog leg in the drain line and change the "P" rgrp into a running trap Code does not addrese this.

3) I am not opposed to opening up the current drain, taking out the trap and simply cutting and extending the line, creating a new p-trap where the new drain will be.

I would definitely go with door #3. I can see backups due to hair plus a very smelly drain in your future if you offset the trap. Good luck, Tom

hobbzilla · May 3, 2009, 03:03 PM

Tom,

Thanks, after I cut the slab and cut the existing trap and extend the line and make the new p-trap, what kind of slope do I need to adhere to in order to allow the shower to drain properly?

I know the shower pan is 1/4" inch drop per foot...

Thanks in advance!

speedball1 · May 3, 2009, 04:13 PM

I know the shower pan is 1/4" inch drop per foot...

And so is the 2" drain line. Good luck, Tom

hobbzilla · Jun 3, 2009, 08:38 AM

Tom,

Was this is your vision put into place?

More photos available here.

I got a little pex work involved to as you can see under the tub. I put in some new fixtures that were all done in copper and sweated on. Put in some ball valves just in case I need to do it again!

Milo Dolezal · Jun 3, 2009, 08:44 AM

Nice... 2 things:

1. Drywall: is that drywall approved for wet location ?
2. To maintain even flow, Body sprays should be roughed-in in a loop-type installation . See drawing...

Otherwise, you've made good progress... It looks nice and clean

hobbzilla · Jun 3, 2009, 09:07 AM

Milo,

1) No the drywall by itself is never a good idea to use in a shower. However, I'm using Schluter Kerdi as a water-vapor barrier. The manufacturer recommends installing it directly on standard drywall. More info can be found on their website.

2) Yes I read that in the instructions... I ended up biting the bullet and sub'd out the slab & plumbing to a pro. It is too late to update the plumbing -- and quite honestly, I probably won't be using them that much anyway -- I'm all about the rain shower head! The sub assured me that for just 2 spray's it wouldn't matter... oh well. Live and learn!

I think I got a good deal. He stated the plumbing company he works for would have charged $1500-2000 for this job; I paid him half that. It took he and a partner close to 9 hours to do all the work in one day. It would have taken me a month in my spare time.

Milo Dolezal · Jun 3, 2009, 09:15 AM

Great, I am glad you are doing it the right way and using the materials designed for shower installations. I couldn't tell from the photos...

As far as the body sprays go: If you won't use them too much than it should not be a problem. It is mostly only a visual thing, anyway. Without the loop, flow may be uneven. Advice: get Hans-Grohe or Grohe body sprays heads. They have very low flow that accommodate 1/2" pipe and 2 sprays.

Once again, great job ! Please, don't forget to post photos of finished project for all of us to enjoy ! Good luck... Milo

speedball1 · Jun 3, 2009, 03:14 PM

Originally Posted by hobbzilla

Tom,

Was this is your vision put into place?

More photos available here.

I got a little pex work involved to as you can see under the tub. I put in some new fixtures that were all done in copper and sweated on. Put in some ball valves just in case I need to do it again!

That's exactly what I had in mine. Once you get that manifold in a wall you can loop it up and drop it down and pick up anything you choose. Nice job!