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CabinCrisis 10-23-2012 01:36 PM

Replacing in-slab shower base.
Hello everyone, this is my first post so bear with me.
I'm in the middle of a complete bathroom rebuild at a cabin I just bought last summer. I am having a solid state shower put in and am trying to get the plumbing ready for the install. It is going to consist of 2 shower walls, which are exterior concrete block that I will need to frame out to fit the plumbing/fixtures. It was originaly just tile directly on the block. The drain is in-slab and very close to the corner of the exterior walls, so it will need to be moved before I frame out the walls. I have also discovered that there is no shower pan. It appears that the slab was cut out and filled back in with sloped concrete and they tiled on top and called it good. (while looking for the pan I hammered one area out until I hit dirt:eek:)
So now that I have damaged the existing concrete and need to move the drain anyway, I feel I need to just remove all of the concrete in the shower base, do the drain work, and fill back in with concrete. I'm just nervous about taking up that much of the slab so close to the exterior walls. Is this OK to do, or am I asking for trouble?

paintdrying 10-23-2012 02:12 PM

just the slab
The walls are wood and sit on the slab? You do not want to undermine the support under a load bearing wall. A picture would be nice. Also they cut the slab to pour the pan, so it was done once. Now you are going to just do more.

CabinCrisis 10-23-2012 02:29 PM

1 Attachment(s)
The walls are cement block. I am going to fur/frame over them just enough to get the shower fixtures behind, cement board, shower walls.

Also they cut the slab to pour the pan, so it was done once. Now you are going to just do more.
Thats what I was thinking, but the more I open this cabin up the more doubts I have about everything that has ever been done to this place, it's a real DIY free for all out here and not the good kind!

CabinCrisis 10-23-2012 03:45 PM

Does anyone know what would be the best way to get all the cement out without damaging the drain pipe? I've been using a sledge hammer but I have stayed away from the drain so far.
Also, once I am ready to fill it back in is there anything I should know? Just pour the cement in the hole on top of the dirt? Any special type of cement?

paintdrying 10-23-2012 10:11 PM

oh boy.
You will be fine, try and not expose to much under grade. If you actually have a footer you will be fine, but realistically you should be just fine. As for breaking up around the drain pipe, I would just go for it, if you break the drain so what really. As for the pour itself, that is a whole other can of worms. The type of pan, drain, liner ect. I wonder who on here would put a piece of two inch foam board down to insulate the slab? Who would use rebar? Lot of different ways to get things done,I would say spend a few hours on youtube. On a side note, your questions may also be answered by other tradesman. Back in the day plumbers ran pipe and other tradesmans did the other stuff. Just saying

CabinCrisis 10-23-2012 10:36 PM

Confidence is high
Thanks for the reassurance. I'm going to let the shower guys handle most of the rest, they just need a level area with the drain stubbed up a few inches. The solid state shower eliminates the pan, slope, etc.
I'm sure I will be back when I start messing with the drain pipe.

oh'mike 10-24-2012 04:38 AM

You really need to know what you are going to use for the new pan before you replace the concrete---

The placement of the drain and the height of the pipe is critical--

CabinCrisis 10-24-2012 08:40 AM

The company that is installing the shower pan(base), walls, etc. builds to suit. It is going to be a solid acrylic stone looking job. They can put the drain hole in the base anywhere I need it, all they said they need is the drain pipe stubbed up at least 2" above the slab. The only reason I am moving the drain is that it is going to be too close to the corner once I frame out the walls. All the plumbing was originaly dropped in from the ceiling.
From what they tell me, once I have all the plumbing in place and the cement board hung, they come out and measure everything, fabricate it at their shop and install. What could possibly go wrong...right?

oh'mike 10-24-2012 05:12 PM

I build bathrooms---that sounds wrong----

Typically the pan fits tight to the framing--then the rock goes up---tile covers the pans flange and water will stay in the pan---

Open only the portion of the floor needed to relocate your drain and trap---repair the missing concrete leaving an opening about 6 or 7 inches across around the pipe---have some gravel available to fill that when the pan setters arrive.

It is important that the pipe has a little wiggle room----

Ask for a drawing of the typical shower pan/wall/backer board set up-----I've built a lot of showers--many using the cast pans you are describing --and never had one that didn;t have the rock on top of the pan flange---

CabinCrisis 10-24-2012 05:32 PM

I'm sure you are right about the cement board. I remember them saying that they do that part.
I'm afraid that I'm still going to hammer out all the cement though I'm sure it's pretty fractured due to my exploration with the sledgehammer. I also have the feeling that it may not have a trap. So you think I should leave a trench around the pipe when I'm done?
I would love to have a professional do all this but I can't find anyone that will show up as this cabin is in the middle of nowhere. I'm on my own.

oh'mike 10-24-2012 06:48 PM

No trench----open the concrete--rent a small chipping hammer if you can---do the drain moving work---refill and bury the lateral pipe and P-trap in gravel----

Make a small wood box form to keep the pipe from getting trapped in the new concrete--

Then mix up a bag or two of Sackcrete--and replace the missing floor----leaving the new pipe sticking up inside of your form.

Don't over fill the patch area---low is good---the shower base guys will mix up masons mortar to bed the new base into--so any low places will be filled at that time.

If they are adding the base and the rock---you need not worry----I always water proof the new rock with a paint on membrane like Red Guard or Hydroban---so I do not put a vapor barrier behind the rock----Mike----

CabinCrisis 10-24-2012 07:52 PM

Thanks for the tips Mike! I would have sealed that pipe right in the concrete.
One more question, I only have 1 vent pipe for the bathroom and the kitchen sink, it appears to be tied in to the main drain line under the slab, there is nothing tied into it above the slab. This is wet venting right? Everything seems to drain fine, but if I need to change it up I guess now is the time.
The drain pipe runs like this: bathroom sink, shower, toilet, vent, kitchen sink, septic.
Thanks again, I love this site!

oh'mike 10-24-2012 11:31 PM

Without a picture or a diagram I can't say much about your venting---If it's working well---leave it alone--

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