Moving a shower drain on plywood/mud subfloor

[Aletia]

Greetings - a homeowner here, but we're looking at a bath remodel with a curbless shower, and without going into the history, we need to relocate the drain that was installed in the pre-sloped plywood subfloor. The drain center is off by 3" - which doesn't sound like a bunch, but it's supposed to be a trench drain, and it won't fit unless it's centered. Obviously, a new hole can be drilled - but what steps need to be taken to repair the subfloor and waterproofing? It's over a crawl space, and the shift to the left is parallel with the floor joist. A 6ml vinyl later is installed on the preslope, but the mud layer wasn't yet applied. So we also need to understand whether a whole new sheet has to be re-applied, or if it can be pulled up and reset in the correct location.

Thanks so much for any recommendations!

 

[Jadnashua]

Some of the companies will custom fabricate the drain and can put the drain outlet anywhere, but if you already have it, you probably don't want to deal with that. There are all sorts of things that can go wrong with this type of install. How are you attaching the liner to that drain? Most of those I've seen are not designed as clamping drains, and are designed for surface bonded membranes. Is the slope at least 1/4" per foot to the drain? Did you have to cut the joists to create this? Have you run the deflection numbers to see if the floor is strong enough for tile after doing that (or even before!)?

But, while not endorsing your build plan (I think it has flaws, but you have not provided enough details), I think I'd consider installing some blocking underneath in the crawlspace, then cutting a plug the proper size, fitting it in the hole. Given a couple of joist hangers, the blocking, and maybe some construction adhesive, you can patch that hole so it won't be an issue.

Now, what liner is there? Is it rated to be installed directly over plywood? How are you planning on terminating it in the main floor as a typical conventional liner won't work as is to set the room tile on and you may not want to mud the entire room. Liners often can be seamed, but it's nicer if it can be one integral sheet. IN this case, the patch might create a wet spot as it would slow flow of any accumulated moisture in the mudbed.

Lots of questions, lots of room for problems. The hole is the easy part!

 

[Sponsor]

 

[Aletia]

Thanks to both of you for your replies - the point about the clamped drain caused us to investigate further, and we finally clarified what we have been told is happening. The plumbing inspection is scheduled, and this is being done for that purpose - and after the inspection, will be removed, the rest of the mud goes on, then the trench is dug out for the trench drain. Unfortunately, assuming this is proper, the issue becomes one of communication rather than method (or at least I hope). It still seems odd that you do things one way for the inspection, and then rip it out.
A week ago, we asked about why the hole was placed off center (since the Jaclo drain has an integrated exit at the center of the drain unit), and we got no clear answer until we found the Jaclo install instructions online, and asked him about it when he came this morning to prep for the plumbing inspection. So maybe we're ok. Unfortunately, there have been some communication issues throughout the project, we're getting uneasy, and it's a lot of $$.

 

[Jadnashua]

You can put your drain anywhere in the shower...most people try to get it closer to the center when using a clamping drain, and there are more options when using a linear drain. John is putting words in my mouth...just to be a pain and to try to instill doubt in anything I say - such a professional! The key is you need to maintain a MINIMUM of 1/4" per foot slope to that drain, regardless of where it is. If it isn't centered, that will often mean that the slope from one wall will tend to be steeper than the slope from the others - IOW, it will have to be steeper than that 1/4"/foot OR, you will not have a level perimeter, that most people like. Using a linear or trench drain, you will have sloped wall/floor lines on at least a couple walls. Say you have a 6' wide shower...the round clamping drain is 1' from one end...that means it is 5' from the further wall, or a minimum of 1.25" drop from that wall to the drain (actually more to account for the hypotenuse of the triangle into the corner...that will be more than 5'). If you want the perimeter level, that means that in the one foot to the other wall, it would have to have 1.25"/foot, or 5x steeper! Having a level perimeter is an aesthetic thing, not a physical requirement. There are limits to where you can put the drain and have it both look good and perform well. SO much for John's assertion that you can put it anywhere!

While what you are seeing happens (putting in a liner, testing it for the inspector, then tearing it out and essentially starting over), at a minimum, once the new liner and drain is installed, you need to do another flood test to verify what was done was done properly. MOst plumbers (not all) wont' do a mudbed to put in a preslope. Most contractors don't want to schedule the plumber in twice - once to install the drain and later to install the liner after the preslope has been installed, with the tiling guy in there in before and after. If they are going to move the drain, that could affect the slope of the drain lines, the depth of the trap, how well the vent line works. All of the things that were tested during the inspection, now changed.

Technically, the liner is the waterproof layer, and code requires it to be sloped to the drain. An inspector SHOULD NOT approve a shower install without that layer sloped, but it happens. They wouldn't approve the drain pipe being run with no slope...they should not approve the liner with none, either. Tearing out what was inspected and approved happens, but it's got its potential problems, both with compliance and ultimate success. Good luck. IT may all work great when done. The inspector is not really your enemy.

 

[Aletia]

Thanks, Jim - I don't believe the inspector is the enemy - in fact, I hope he's my ultimate salvation. But maybe that's too optimistic.
Unfortunately, after our GC explained that this was all "for the inspection", he came to me and said that his plumber didn't want to install the drain per the mfr's instructions, that he wanted to use the clamping drain after all, and then install the trench drain above the whole mess. I asked about how he will maintain the slope that way, and won't it raise the whole floor, making transitions even more of a problem? Called the manufacturer yesterday, who confirmed that no clamping drain needed - but if you do, they offer one that can be used (vs. the one he had), but they don't recommend it. They also confirmed that if you do that, the subfloor needs to be dropped even further, since you're forcing the bottom of the trench drain up 1 3/8" higher. Which is what the GC and I discussed. Unfortunately, as we were getting frustrated with each other, the inspector came, and blessed what was there. Seems like GC's trying to figure it out as he goes along, without any clear understanding or plan - and being a IT SysAdmin myself, I find this troubling. I asked about reading the install information with the product - was told "they don't read manuals, they're tradesmen!" When I encounter new stuff, which I do all the time, I take time to try to make sure I'm approaching the problem correctly.
The question now is how to salvage the project, and secondarily, the relationship.

 

[ShowerDude]

simple answer, tear out liner and start with a new plan. . (edit rant)

start first by demanding A proper Flood tested shower pan before you do anything else.

and be sure to repair subfloor properly while at it( a whole other discusiion)

why gamble on your expensive remodel ? from what ive heard you are on the wrong path to a major loss of time & $ and still chasing a compromised plan and result.

 

[Eurob]

I asked about reading the install information with the product - was told "they don't read manuals, they're tradesmen!" When I encounter new stuff, which I do all the time, I take time to try to make sure I'm approaching the problem correctly.
The question now is how to salvage the project, and secondarily, the relationship.

You don't even mention what product you are trying to have installed ..... must be quite easy to find the instruction manual for an IT SysAdmin.

Talking with your GC about the differences in between steps could get you an understanding of what he is trying or going to do .

 

[Jadnashua]

I totally agree with the comment about reading the instructions...too many things are changing, and not reading the instructions can be catastrophic. ON another forum I read, there's a discussion about how Custom changed the formula of their self-leveling cement. They changed the amount of water (and the formula) so it now uses less water. Guess what, it changes how it functions, and would be catastrophic to the job if inadvertently mixed with the old water amounts. Even for something you THINK you know about something....you should read the instructions, since the procedures may have changed.

I do not claim to know it all...but, I do claim to be able to read and understand (or ask enough questions until I do) the installation instructions on the products that I talk about. For the most part, with a company that has been in business for a long time, I believe they have figured out what works and what doesn't, and how best to install it for ease and function.

 

[Aletia]

Thanks for the comments, all. I'm not sure how things can be resolved. The trench drain is a Jaclo Zero-Edge drain body, and yes of course I easily found install guides online. Showing the GC these guides made things even worse - do I trust the manufacturer, or a seasoned professional? In this case, I think I'm figuring out the answer (trust the manufacturer...). He still wants to do things "his way".

The question of due-diligence in the identification of a contractor is a reasonable one. We thought (of course) we had done what was needed. The company has been in business since 1963 (family business). We called at least four number of references from previous bathroom projects, went out to visit a family in a very nice home, for which this contractor did major renovations / additions, and talked to additional customers who had curbless showers installed by the company. BBB ratings were fine. Angie's list wasn't perfect, but very good. So we thought we had covered the bases. What we don't know is whether the project manager assigned to our project was the one who did the others. As things go on, I suspect not, although he was specifically mentioned in a couple of the Angie's List reviews as being very good.

It really does feel like he's faking it, unfortunately, and this project is not a simple one - it requires planning. This issue has come up between the two of us multiple times. He charges into to stages of the project, and then has to be pulled back and work has to be redone. I mentioned that trying to add the clamping drain and then the trench drain will screw up the slope - he said that we don't need a 1/4" slope, which I know we do.

I'm thinking of finding another contractor to inspect the work that's been done and determine whether it can be salvaged without a total tear-out. But how do you find someone credible? Do I have to cancel the current contract and then deal with lawyers? Such fun. Thanks for your observations/recommendations.

 

[ShowerDude]

Being in your situation is tough.

I am not siding with anyone here.

how could i? i am not in your home looking at your shower nor have i seen a single pic or drawing.

from what you e explained it sounds very questionable.

i feel for you and your contractor both.

If you are unable to understamd how he intends to build your curbless sbower or he is simply not explaining it clearly to you. cant you request a stop on the shower portion of your project and have a meetng with everyone involved?

we are listening to your issues but have yet to see a single diagram or drawing of your situation. and cant advise without a lot more info.


I will say this. You seem to be dealing with a reputable contractor that has been in buisness a long time and id tread lightly on abusing their company or name online until you give it a chance to rectify.

It is possible they know more than yourself ??? and do have a proper plan. maybe there is just a communication error, can you request the owner of the company comes out? tell him your concerns

be patient , we contractors have to deal with different personalitys daily and theres always the strain of $ involved which gets emotional quickly

If you yourself dont understand how the shower is built and works, how can you ask the proper questions and or verify the steps? reading the drain manual
is just a very tiny component in a tricky puzzle...

lastly be careful beleiving all you are reading on various forums .as i see youve posted this elsewhere.. that alone will only stress you and misguide you even more....


best of luck to both parties.....