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First ever shower stall, using Kerdi have questions.

madmadscientist | Posted in Construction Techniques on November 16, 2010 09:21am

I’m under the gun to get my bottom floor bath redo done before the permit runs out. I’ve run into several conceptual issues and could really use some advice.

View Image Here is the plan view of what we are trying to do with the bottom floor bath.

 

View ImageHere’s a total side view of everything. You can even see the ceiling mounted rain shower head and the ceiling fan and light.

 

Ignore the placement of the vanity in this shot it should be rotated 90deg and placed against the wall we’re looking through here. In this version the tiles do not go all the up to the shower head level, do they need too?

View ImageTa-da one clean bathroom space! Now, lets get to the problems….

View ImageI’ve decided to use the Kerdi system and have purchased the Kerdi Shower kit with the 32″by60″ pan. This should have everything I need to waterproof the shower floor and walls.

View Image Problem #1…this is the drain pipe for the shower…notice how it is higher than the floor? Because of where our sewer main is, this is as low as this line can be and still drain properly….

View ImageThe top of this line is ~5″ above the floor! What in the heck can I do about this? So far my only idea is to build some forms and pour some additional concrete in this area to raise the floor level up and cover this pipe. Then I could set the Kerdi shower base on this raised flat-level platform and continue as normal? I don’t want the step into the shower to be any higher than required…anybody have any idea how little concrete above the pipe I can get away with?

Shower Questions

1. The rain shower will project down from the ceiling about 1′ leaving it ~8′ off the floor. How high up should the waterproofing-tile go and how high up should the glass enclosure go?

2. What to do about the drain line being 5″ above the slab in shower area? -Does it make sense to pour a base-footing for the shower to cover the pipe? If so should I use regular concrete? or what? Dry pack mortar?? The Kerdi shower curbs sit on the outside of the pan so I would need to size this base to be big enough for the curbs also?

3. Placing the drain- I’m pretty sure that the existing location of the drain stub-out is off by 6″…I’m worried about adjusting this as it looks like from reading the kerdi instructions that you have to have this placed EXACTLY in the right spot?

4. On the walls of the shower I would like to use plywood so that I can screw in anywhere for the grab rails and not have to worry about it. Whats the recommended thickness of plywood for this application? Can I adhere the kerdi straight to the plywood or would I have to screw in cement board to this? I’m kinda worried about the thickness of this wall 3/4″ ply + 1/2″ backer board + 1/2″ tile…maybe I don’t need to worry about it?

That’s part one any helpful advice would be greatly appreciated. I want to have showerbase issue figured out and done by the weekend if at all possible…

 

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Replies

  1. User avater
    madmadscientist | Nov 16, 2010 09:24pm | #1

    I'm sorry guys I do not know what I'm doing wrong. In the preview the pictures show up but on the post they don't?!?!?

    If you click on the picture it takes to to it.

    Hello editors-site managers? Why is this happening? When the pics are hosted off site why do they show up fine in the preview but like this in the actual post?

    1. calvin | Nov 16, 2010 09:37pm | #2

      no way hose A.

      You will have to import the file from your computer...............

      or

      save them to the desktop from the site (such as diagrams and product pictures), then upload that file here.

      A real bite me situation for sure. 

      1. User avater
        madmadscientist | Nov 16, 2010 09:54pm | #4

        WHY!

        What is the point of that?

        Do they want to 'Own' all the pics or something?

        Why wouldn't they want the pics hosted off site they will save on bandwidth and hard drive space?

        Oh well, dang, if you click on the blog link in my sig you'll basically see these same posts....

        1. calvin | Nov 16, 2010 10:18pm | #6

          What is the point of that?

          I don't know Daniel.

          Why don't you ask? 

          and when you do, point out to them again how easy it is to explain something when you can narrate right along a posted picture or diagram.

          Be sure to mention how valuable the countless picture threads were, and the value of the loss done with little thought during this changeover.

          You might even point out that we cannot change our profiles, nor know when people have read a reply.

          Oh hell, don't piss around.  Find someone that'll listen and tell them what you think.  You just might be the lucky one.

  2. User avater
    madmadscientist | Nov 16, 2010 09:52pm | #3

    Bonfire of the Vanities

    Looking at how exactly I am going to install the bath vanity and have run into a couple of problems.

    View ImageHere's the vanity we got from the Home Decorators Collection.

    View ImageNotice the fancy sides and top edges. This thing can not be placed flush against a wall on its short sides.

    View ImageAnd here is problem numero uno.. This is the stub-out for the sink drain...its only 4.5" from the wall....not sure how I managed to F this one up so much....because of the position of the stub-out the drain lines for the vanity can not come in through the openings in the back of the vanity. The only thing I can think off here is to cut a hole in the lower corner and bring the drain line in that way. I'll probably also have to shorten the drawers on that side as they look to slide all the way back to damn near the back of the cabinet.

    View ImageHere's a shot of the back of the vanity showing the access holes for the drain and water supply lines.

     

    Which brings me to issue #2. How to get the water supply lines in. If I have the vanity as shown in the previous post they would have to come in from the side which will be visible from the front.

     

     

    One thought is, is that if I raise the vanity up enough I might be able to bring the lines down the wall and have them enter the cutout just above the sole plate of the wall. For this to work I need to raise the vanity up ~4".... I'm not sure what's the best way to do this.

     

    View ImageHere's a shot of the legs that came with the vanity. They measure ~7.5". Could it be just as easy as buying some legs that are 4" taller? With the stock legs the vanity top is at 36" which I feel is a bit low for me and for elderly folks. I think 40" feels a lot better and with the taller legs it'll be easier to clean under it?

    Vanity Questions:

    1. What to do about getting the drain line into the cabinet when the stub out is unfortunately placed.

    2. What's the best way to raise the vanity cabinet up ~4" so I can get the water lines into it easier?

    Any useful advice would be greatly appreciated.

    1. calvin | Nov 16, 2010 10:11pm | #5

      Raise the entire floor in that bathroom

      And hope that a step down into the "hall / whatever" won't cause as many headaches as one out from the shower.

      That'll fix your vanity height problem also.  Unless  you're 6'8" , raising the vanity up to almost 40" would be a mistake.  Think about brushing your teeth while you're sauntered up to the bar.

      Wall spout?

      1. User avater
        madmadscientist | Nov 17, 2010 04:34pm | #9

        thanks Calvin

        For the reply.

        I'm only 6' tall but I have 2 bad discs and I find bending over to wash my face in a bath sink to be a lot less painfull if the countertop is higher than the 'standard' 36" On our previous kitchen we set most of the counters at 40" and I loved it.

        I'm honestly not trying to be difficult here but I really don't see how this situation where the top of the curb will probably be ~10" off the floor and the shower floor will be ~6" why that's so horrible? A standard tub-shower combo has a 18" lip and I don't think people typically build steps  in front of them?

        Though I do believe that I will have room for a 12" deep step and I think if I put it at 6" then it would just be a 4" step over the curb?

        1. calvin | Nov 17, 2010 06:32pm | #12

          Here's my take on the shower level.

          and you should mock up what you are talking about so the wife and kids can do their step thing.............

          A tub is a tub.  You expect to step over that 15" thing to get into it.  And it's only a bit higher than floor level to the bottom of the tub.

          In your proposed shower, you are stepping up over a curb and down 4" to the shower floor.  Now, that's not bad, but when you leave, you're stepping up over that curb and then down ..............a pretty big different level.

          Please, build a quick mockup and have them try it out.

          With wet feet on a slippery surface.

  3. User avater
    Homewright | Nov 16, 2010 11:46pm | #7

    A couple questions here...

    What is in the space behind the shower where the pipe is running through?  How much space if any is available in there?  You can feasibly run a drain beneath the level of the main then pump it into the main but again, the space to accomodate the set up is what my question refers to.

    Why aren't you using pressure treated plate material in your walls?  If you're doing a permitted job, I'm sure the inspector might make issue with this oversight.

    The drain coming out of the concrete for your vanity could also be corrected if you're willing to cut some concrete.  A diamond blade on a skilsaw and a handsledge with mason's chisel would allow you to redirect the pipe to the appropriate height/position.

    I don't recall offhand what the Kerdi recommendation is regarding plywood but I just installed a steam shower and we put all 1/2" backer in.  Plan ahead where you want grab bars and do the same blocking as seen in your photo at the appropriate placements for your grab bar mounts.  Then you can forego the plywood altogether and just put in the backer board on your framing.

    If you're pushing to beat a permit's expiration, you might be setting yourself up for a domino effect of troubles by rushing through some critical details.  Not to sound rude but shouldn't you have been doing this before now?

    1. User avater
      madmadscientist | Nov 17, 2010 04:41pm | #10

      Thanks for the reply

      I am aware of pump systems but I strongly prefer my plumbing to work when the power goes out so I'm against using them if I can get away with it.

      Not using PT plates in the walls for the bath but I've got peel and stick membrane underneath them and they've been there for about two years and look as dry as can be. Job is of course being done with permits. I'm going to try to have the inspector out Friday to do a 'preliminary' framing inspection to see what he has to say....

      I've got to look more deeply into the Kerdi specifics...the install instructions say you have to install a strong-stiff wall covering to support it so I thought why not use 5/8" ply to match the drywall around it and I'll be able to screw in non loadbearing shower widgets where ever I want. I have already added some blocking but I guess I just will add more in every possible place we could want to install grab bars.

      Ya, shoulda done this looooooooong ago.

  4. interlodge | Nov 17, 2010 09:53am | #8

    Kerdi

    No plywood directly under kerdi. Block between studs for handholds as suggested earlier.

    Schluter (Kerdi) actually prefers basic drywall applied with a non modified thinset. You can use cement backer (CBU) but it can add a few installation issues that might cause a beginner difficulties, like hardi is so thirsty it prematurely dries out the thinset causing setting and very possibly curing issues unless you really wet the board before application ( or use a diluted admix primer compatible with the thinset) . Other CBU's have similar but maybe not as exaggerated issues.

    Good idea to thoroughly read

    http://www.schluter.com/media/ShowerHandbook.pdf

    PT plates. I am not commenting on overall construction, I didn’t even look at the pic to see where they were used, However do not use any regular PT wood in the shower construction anywhere. It shrinks to much and will crack tile and mortar. If you are required by code to use, you must find KDAT pressure treated (kiln dried after treatment)

    Otherwise put a strip of plastic under the framing if warranted (like on concrete).

    Height of shower, As suggested they do make evacuation pumps for showers. They also make premade shower receptors, that can be combined with tile walls, that incorporate a shallow rise above floor with an evacuation pump.

    I think raising the 6 inches is above thickness specs for drypack mud bed. I’d have to check on that and think about options. If it was me I’d prefer not to pour an actual concrete lift just in case I ever had to get to the plumbing again. There probably is a good method if you still choose to go that route of elevating the shower

    1. User avater
      madmadscientist | Nov 17, 2010 04:45pm | #11

      going with

      A wood base for the shower...that way the pipes won't be incased and inacccesable and I can build the platform so that I can get at the drain couplings to wiggle things around if need be.

      It just seems strange to me that Kedi prefers regular drywall? I wonder why plywood is allowed? I mean it'll stick to paper faced drywall just fine but the wood doesn't work?

      So what do you think about how high up the tile should go? All the way to the 9' ceiling? or what?

      I actually downloaded the Kerdi manual and have been reading it...gonna look at the install videos today also....hopefully I won't be so clueless for long.

      Thanks for the reply.

  5. User avater
    madmadscientist | Nov 17, 2010 09:45pm | #13

    conceptual problem solved
    Finally got my mental issue with the raised shower floor being a problem. Got set straight on the breaktime classic forum.

    What I was missing was the step down from the inside isssue. I was only thinking about getting into the shower.

    So, my rough plan now is to extend the raised wooden platform to include a step/landing on the short side which is where the shower door will be.

    Consensus seems to be that the height of the platform should be the same as the shower floor.

    Also I will use 5/8" drywall for the shower walls and kerdi and tile all the way to the ceiling but stop the glass walls 6" from the ceiling.

    That's the rough plan for now gonna build the platform tomorrow.

    If I attach the platform solidly to the wall framing does anyone think that it will be necessary to nail the bottom plate to the concrete?

    1. calvin | Nov 17, 2010 10:06pm | #14

      I would fasten everything

      You let something float and use tile, expect cracks in at least the grout.  But you could get further opinions over at the Classic.  There's alot more brains there.

    2. interlodge | Nov 18, 2010 04:20pm | #15

      the bottom plate must be fixed. The slightest movement will leads to cracks as Calvin suggested.

      Good choice on the drywall. 5/8 is a bit more solid. The reason plywood doesn't work is plywood expands and contacts with humidity changes (very minimumly ) . It is not a completely stable substrate. Tile likes a stable substrate.  cbu, tile backers like denseshield, or drywall with a surface membrane are all stable.

      I'm not a big fan of a step but if that's what you have to do if you don't want a pump.

      I think code might require a handrail for a shower step even though it's only one step(IRC)  .     AaAsk your inspector as I'm not sure on that

      1. DanH | Nov 18, 2010 04:31pm | #16

        Certainly a handrail at the entrance isn't a dumb idea, whether it's required or not.  And it would be wise to at least install blocking inside for future handrails, and take pic tures/measurements of where the blocking is.  (Put copies of these in an envelope taped to the inside of the vanity cabinet or some such.)

      2. User avater
        madmadscientist | Nov 18, 2010 05:25pm | #17

        this is going to be
        An elderly friendly bathroom so I'm planning on putting grab rails all ober the place so obviously putting some near the step.

        On fastening the plate......if I can find kdat wood I'll build it out of that...

        I'm worried about the radiant tubing in the slab which I am sure will be under the area of the platform.

        Do you think that there is a way to securely fasten the plate without penetrating the slab?

        I do own a ramset but knicking one of those tubes would be a huge setback...

        1. calvin | Nov 18, 2010 05:49pm | #18

          Careful planning

          Daniel,

          Whenever floor heat is involved, a final plan must be in place for any and all walls and other potential fasteners into the floor.  Since this bath must be after the fact I think you could PL Premium the wood down to the concrete-wedge in place while the glue sets.  And, take precaution to  not bang it around framing on top of it.  Nail gun or screws to do the rest of your assembly.  Or, assembly the parts, set them in the PL and brace in place till it sets.

          You have any pictures of the hose install?

          1. User avater
            madmadscientist | Nov 18, 2010 06:39pm | #19

            yep
            Careful planning is always the best....

            As only a resonably competent diyer I admit that I F up a lot more than the experienced pros here do...

            I do have good pics from when we did the radiant install...which is why I know I'm screwed.....

            This was supposed to originally of been a clawfoot tub soooo....

          2. calvin | Nov 18, 2010 07:34pm | #20

            Daniel

            With common 6" or slightly more centers on the hoses, you still are not confident missing the hose?  Would the depth of hose allow any help?

            With the PL on hopefully not fresh concrete and walls wedging that box down...............you might get away with it.  The step and any "glass" wall will be the week point.

            I see now why you didn't want to raise the whole floor.

            Hopefully you'll figger a way to capture the heat below the raised shower floor.  Nothing nicer than a warm floor.

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