Mixing Kerdi and mortar beds in new shower

[am118]

Folks,
I'm building a custom shower (78" x 40").
My drain is about 23" from one end.
I was thinking about using a 48" x 48" kerdi shower pan (and cutting it to fit the drain end of the shower) and then using a mortar-sand bed for the remaining shower floor area (about 30" x 40" or so) at the other end.

Is this doable?
Some say not to mix the two systems.
Others say go ahead.
Any advice?
I figured that once the tile is over both, there wouldn't be much difference.

Help?!

J.

[jadziedzic]

The Kerdi tray has a fixed slope built into it; if you extend one side (with a mud bed) then to maintain the proper slope the far end of the bed will be about 5/8 inch higher than the opposite end of the Kerdi tray. The tiles on the mud bed end will be cut 5/8 inch shorter than the ones at the Kerdi tray end, and the ones along the long walls will have angled bottom cuts. You'll get better results with a mud bed for the whole area (and save the cost of the expensive Kerdi tray).

You might want to wander over to the John Bridge tile forums (http://www.johnbridge.com/vbulletin/...isplay.php?f=1) - there a LOT of knowledgeable folks there.

[jadnashua]

the tray works well IF you can cut or add (nearly) the same amount from all sides. Ideally you want the drain in the middle, too so that the slope is similar from each end. You should try to have the outer edge the same height all the way around. That means in a rectangle, the shorter side will be steeper.

[johnfrwhipple]

In my opinion you will get a much better looking shower with a linear shower drain and one way slope. The Kerdi drain can be extended but the slope will be messed up as it will look good on the short end (kinda) and then go cockeyed on the long side. You will get a better look with ProSlope and the best look with a linear line drain.

I would use mortar ( 4-1 dry pack, 5-1 dry pack, 3701 Laticrete etc) only on the floor of the shower and not the foam pieces that come with a Kerdi kit. I bet when you compare the costs the linear shower drain and ease of installation - you will be installing your first trench drain. That is a large area to funnel water into one small 4" point. A ton of grouting. A Ton of cutting...

Are you building over plywood or concrete?

Remember if you decide to use a Kerdi drain you will need to use Non Modified thinset for much of your work. Check your dates carefully as this is the cheapest kind of thinset on the market. You can get a 25 year warranty with a Laticrete shower - I think the Kerdi system is 3 maybe 5 years at most...

I can help with your build in any way. I have been building showers for about 20 years now. Never have I nor never will I use the Kerdi shower kit. To much styrofoam and the wrong setting materials in my opinion.

Before taking any advice online ensure the person offering it to you is still in the business. I think you will find most posters on John Bridges web forum (the heavy posters) are all retired... Many are not even in the business I have found. Ask for a company name. Check references. Look for free advice - many websites try and get you to pay for extra advice in the way of ebooks and such.

Good Luck.

John Whipple
By Any Design Ltd.

Vancouver

[johnfrwhipple]

Here are some good reading sites for the Kerdi Shower Kit. http://www.schluter.com/media/ShowerHandbook.pdf

Look closely at the pictures showing the pitch out from the center. Once you extend the shower you will have a one way pitch for a distance and then pitching back to the center. This will make for some tricky tile setting...



Here you can see how the floor pitch will alter. Looking into the shower if the entry was along the long wall the tiles will slope left to right then level out. This will like very odd in my opinion.

I would call Schluter directly and ask them which kit to use. Their rectangular kit would be a better fit for your install - not perfect but better than the square one your suggesting...



This is Schluter's tub to shower conversion kit. This would be a better choice for your shower. My sketches are close to scale. With this setup you could get a much better looking shower.

You can reach Schluter's tech support here;

USA: 1-800-472-4588
Canada: 1-800-667-8746

And learn how to read thin set production dates. Many non modified thinsets are quite old as many stores carry very little of this product. Work with thin set no more than 8 months old if you can. 12 months at the very longest.

Some stores that sell Schluter's products don't carry non - modified thin set so you might need to go to a tile store.

JW

[johnfrwhipple]

Here is line drain, slot drain, channel drain, trench drain or what ever you want to call a long rectangular drain installation.

The pitch only needs to go one way on each side of the shower.



You can use a regular shower drain and go with a traditional install and it will look something like this;



This video will show you a simple approach from Nobel Company to grading your shower floor...



Here is a video from Quick Drain USA showcasing their install system;



An video showcasing ACO's linear drains here on Designing Spaces;



You can order line drains from ACO, My Shower Grate Shop, Nobel Company, HeelGuard USA and Quick Drain USA. As yet Schluter has no approved line drain with UPC classification. They might sometime this Spring but are still working on a Prototype to my knowledge.

Good Luck.

Please let me know if I can help in anyway...

John Whipple

[am118]

Wow!

Thanks Guys for the great information.
John, your diagrams and suggestions are outstanding (especially for my novice brain).

We thought about the extended 60x30" Kerdi drain but the drain doesn't line up.
The idea about the Proslope is new. And it can be used for the 78 x 40 without any problem?

With such a gentle slope, is it THAT difficult to tile? We're using the 2x2" tiles on the shower floor.
The door is on the top left of your diagrams (and is about 28" wide).

Thanks for all the help..I'm overwhelmed!
Cheers,
J. Norrie (Nova Scotia)

p.s. One last thing, is it out of teh ordinary to mix the Kerdi or Proslope systems with mud beds? Does it affect the "walking" texture or feel of the shower floor?

[jadnashua]

If I was going to do this and was using kerdi, I'd build it all with deck mud. If I could, I'd center the drain.

[johnfrwhipple]

Your welcome.

A 2"x2" tile is ideal for a Kerdi Drain and of course you can Kerdi over a mud floor.

The Kerdi pre made kits take the hard part out of building a shower floor and the messing around with cement and sand. That said if you need to do a fill in you might as well do the whole job a mud job. It will make for a much denser floor.

I'll look for some more videos for you and must warn you that many videos online show this process incorrect. What town are you in? Let's find out first what "Products" you have to work with.

If you can send me your town (I understand if you don't want to and can email you my reps names if you prefer) I'll ask my suppliers to send you an email letting you know where and what is available.

There is a hundred was to bake Chocolate Chip Cookies at least - and just as many ways to build a shower floor. First step is an ingredients list...

More Questions for you;

Are you in a rush? Do you have kids that need this working right away? Are you on a budget? Do you own tools or have access to them? Are you able to transport heavy bags 50lbs etc?

All of these play into the equation. This is the fun part the planning.

If it works on paper - it is going to work in the field or in this case your bathroom.

We mudded out a shower floor today. I'm off to soccer practice and will post a few shots tonight or early morning.


To answer your question about the proslope you can use them for longer showers but need to order extenders. You can as well make them out of one single 2"x10". You Could even skip them all together if you wish...

It's easy when you have a plan!

JW

Wow!

Thanks Guys for the great information.
John, your diagrams and suggestions are outstanding (especially for my novice brain).

We thought about the extended 60x30" Kerdi drain but the drain doesn't line up.
The idea about the Proslope is new. And it can be used for the 78 x 40 without any problem?

With such a gentle slope, is it THAT difficult to tile? We're using the 2x2" tiles on the shower floor.
The door is on the top left of your diagrams (and is about 28" wide).

Thanks for all the help..I'm overwhelmed!
Cheers,
J. Norrie (Nova Scotia)

p.s. One last thing, is it out of teh ordinary to mix the Kerdi or Proslope systems with mud beds? Does it affect the "walking" texture or feel of the shower floor?

[johnfrwhipple]

If you want to install a regular shower drain or a Kerdi Drain and the drain placement is not centered a great way of greatly improving the look is to use a concealed drain or "Tile Top" drain.

Visit my Shower Grate Shop here and take a look. With shipping the price is most likely the same as you would pay for a Kerdi Drain or perhaps a fraction more...



Yesterday's progress...

I'll make up and example of how this drain looks with the tile top. Once you see it you will be so impressed.

I would still go with a line drain - but I'm partial to these new linear shower drains. Notice as well the CSA label on the video. Ensure all your drains are CSA approved!

More installs from My Shower Grate Shop;

[johnfrwhipple]

We have a great new project starting here in North Vancouver in a few weeks time. It will give me a chance to showcase my Kerdi Drain and Kerdi installation practice.

I am a firm believer in the Kerdi Membrane - Just not the recommended installation procedure offered up by Schluter Canada and Schluter USA.

I will document my process and the only difference between how I will install the Schluter Kerdi sysytem and drain will be the use of Kerdi Fix instead on Non-modified thinset in the seams.

This is key to a watertight installation and our goto procedure here in Vancouver.

Stand by for updates...

John Whipple