Conflicting advice—please help! [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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10-08-2002, 08:58 AM
Hello. I'd really appreciate guidance from the experts who roam here. I've scoured your forum and found many helpful threads, but nothing that really hits the bullseye regarding my circumstance. Forgive me if I missed a thread somewhere.

I've been the recipient of much conflicting advice about how to proceed with my basement shower project. I have a shower area that measures 30" by 48" and the floor substrate is the concrete foundation. Can I tile over the concrete floor or must I install a shower pan? I've been told that a shower pan (mortar bed and polymer liner) is necessary because of 1.) the possibility of foundational movement, and 2.) standing water that builds up between the tile and underfloor during showers.

Conversely, it's been argued to me that a mortar bed/shower pan is unnecessary because there are no signs of any previous structural movement, and there's already a concrete substrate to attach tile to. The question was posed, if a mortar bed is needed between tile and underfloor, why isn't the current concrete good enough? I had no answer to that—I could only respond by saying, "That's what I was told by another contractor."

If a mortar step is needed, how do I go about it? I've also received conflicting instructions about this process. All the photos/directions I've looked at on the Web have been for tile projects with a plywood subfloor.

So what about it? Can I tile right on the cement floor?

Thanks in advance. Do-it-yourselfers like me really appreciate the helpful people in forums like this.

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10-08-2002, 09:19 AM
Hi Cary, number 2 is probably closest to being correct. You need a mud (mortar) shower pan so you can build a slope in the shower so the water will run off. Others will be along with more precise information. In the meantime go into our Liberry, click show all threads and review all the material in there pertaing to shower pans.

10-08-2002, 09:23 AM
Thanks Jim!

There is a drain installed and the current cement floor is sloped to it. Sorry, I should have included that information!

10-08-2002, 11:17 AM
Cary, If you havent Started yet,Let me tell you how i handle basement shower floors.

You dont need a true Pan with floated mud etc,However a good Paintable membrane is good insurance against moisture getting to your sill plates.
I generally paint the membrane up the walls 4-5 inches in a basement and pay particular attention to were the wall meets the floor.Some may consider this overkill,But then i try to build to last,After all its my name going on that shower.
There are several brands of paintable membrane.I have been using C-cures Pro red waterproofing membrane with excellant results so far Good Luck Todd

Bud Cline
10-08-2002, 02:16 PM
I would agree with Todd in this case, the only difference would be I am rather fond of a paintable liquid waterproofing membrane made by the Laticrete International Company.

They have two products that will accomplish this task. The first is the commercial grade Laticrete 9235 and the second is a lessor expensive product from Laticrete called Watertight Floor n Wall. Both products are used with a companion fabric material that you immerse in the liquid after it is applied to the floor/wall junctures. You then paint it again. After allowing the first coats to dry I would recommend a third application of the liquid.

Now if your existing floor drain is flush with your existing concrete floor then either product should work for you.

You should be aware however that not everyone subscribes to this method but it does work fine.

10-08-2002, 02:22 PM
Thanks guys. I've just read about another product called Hydroment, form Bostik. Heard of it? I'm gonna track one of these products down and get to it!

I really do appreciate the advice. Now when I have electrical issues, can u guys motor over to that forum?

10-08-2002, 03:39 PM
Cary, I'd say you have probably come to the right place for conflicting opinions - just hang around a bit :D :D :D

it'll be good advice, for the most part, but definitely conflicting at times...

(Laurie, ducking in

John Bridge
10-08-2002, 03:46 PM
If you have wood stud walls around your basement shower, you do in fact need to install a true bona fide shower pan liner. I don't know where these other hacks have come from. I don't even know them. Bud who? Todd? :D

The Conflictor :D

10-08-2002, 03:51 PM
What..I'm not good enough to be a hack? :D

10-08-2002, 04:01 PM
John, I hope your last post was intended as a jest. I'd gotten my hopes up for a simpler solution. Even if you're not kidding, I'm going to plug my ears and whistle—think Jim Carrey in Dumb and Dumber.

After scouring information throughout the Web, and here on your site, I think I'm going to take the advice of Bud and Todd. After all, one's a "meister," and the other's a "tile guy." Me, I'm just a schlep.

10-08-2002, 04:09 PM
From another schlep....
He's not joking. If there is wood, you need to keep the water off it. These guys will take care of you!

John Bridge
10-08-2002, 04:17 PM
Hi Cary,

I was joking about calling Bud and Todd hacks. They are actually very experienced tile setters and know what they're doing. I think, though, that they have concrete walls in mind. I also think they will agree that a wood walled shower needs a pan. I think. :)

Let's give them a chance to come back around.

Don't listen to that hack, flatfloor. ;)

10-08-2002, 04:17 PM
Yes, the shower stall is framed with lumber, but there'll be wonderboard (what a misnomer; that stuff is anything but wonderful) on the walls, and I thought any shower pan—mortar and polymer, or paintable waterproofing—only rises 6 to 12 inches above the floor anyway. If you paint the waterproof stuff up the walls as Bud and Todd described, isn't it in effect the same kind of thing? Why would a conventional shower pan installation be better for lumber? Am I slow?

John Bridge
10-08-2002, 04:20 PM
Simulpost :) Mine is above yours.

If it were my shower, I'd install a liner and a clamping drain. Maybe I can be talked out of it. Let's here from the boys again. ;)

Bud Cline
10-08-2002, 04:27 PM

No...unfortunately John is not kidding, but John is like that. John has it in his head that his way is the only way to do showers and in fact his way may well be considerd the best way by many in the know.

We've had this argument here before and will continue to disagree on this topic.

You have to remember that John works for a high-end builder that builds new mansions and money is no object.

What Todd and I are proposing will in fact work. I have in the past hesitated to mention how many of that type showers I have "hacked" together without any problem, ever.

Today's products are quality products and your project isn't all that extravagant. I must tell you though I have no experience with the Hydroment waterproofing products and have no idea what their capabilities or limitations may be.

You'll be getting more comments now that we have again opened Pandora's Box here so you must judge for yourself if this is the path you want to go down. We can't be there to guarantee anything.

This method has come to me through architects and engineers that believe it can be done and do it only this way. My customers using this method have been state and county governments whose inspections can be sometimes very rigid. Never once has an inspector or a General Contractor bawked at this method in my experience.

John Bridge
10-08-2002, 04:33 PM
I don't want you to think I'm just trying to be a pain in the butt. It's possible the method will work. I've never done it. I don't understand the advantage of it, though. It's certainly not going to be any cheaper, and you will have to slope the drain somehow.

10-08-2002, 04:40 PM
Ooops. Didn't mean to reignite the Hatfields vs. the McCoys.

Seriously, thanks for everyone's time and input. Just when I was on the verge of losing faith in mankind, you tilesetting professionals have restored my confidence.

I might have to check in here once in a while even after I'm done with my project—this place is pretty entertaining. Although, it's unlikely I'll ever really be done.

10-08-2002, 04:43 PM
John, the drain's already sloped. That's why I've been kind of confused since I took this project on. It seemed like I was hearing stuff that was unnecessary.

10-08-2002, 05:00 PM

Concrete (Below grade) is already sloped to drain, wood framed walls with Wonderboard. Waterproof floor and walls up 6 to 8 inches. Would be best to waterproof walls all the way up, to prevent the possibility of water thru grout into cbu and getting behind wp.

Hydroment makes a liquid applied membrane and also a trowel applied uerathane (Ultra-Set).

I'm partial to Laticrete.:)

Another Hack Rep

John Bridge
10-08-2002, 05:05 PM
Now, come on, Kurt. I've been trying my best to back down gracefully. I'm doing the best I can, man. :D

10-08-2002, 05:26 PM

Sorry, my friend, I smelled blood-came runn' :)

This is One of those applications where a liquid-applied WP is the Best choice. :)

KW :)

John Bridge
10-08-2002, 06:50 PM
Geez, I'm coughing up blood. :D

John, squirming his way outa here, B.

Bud Cline
10-08-2002, 07:37 PM
I'll accept your apology as soon as you also apologize for calling me a hack, John.

Thank you KW. I've been doing this in certain applications for years without any problems.

10-08-2002, 09:49 PM
'tole ya, 'tole ya, la, la, la, la...

....and that's why so many of us love it here! ;)

Bud Cline
10-08-2002, 10:40 PM

John Bridge
10-09-2002, 05:55 AM
Well, just one disclaimer. KW says its the best idea in this instance. I don't think so. I may work, but it's not the best.

I guy can only do so much sucking up, you know. :D

10-09-2002, 07:04 AM
Waterproofing with a trowelable paintable membrane has become Standard Operating Procedure for any Concrete/CBU Shower On Grade or Below Grade.Architectural Resources,the largest architectural firm in Northern Mn.Has Spec'd this type membrane on all jobs in the last 4 years.Above Grade floated showers with PVC Membrane are still the Norm for all Wood Subfloor Custum Pan Showers.Ive Done Hospitals,Schools,Nursing Homes,and Motels with trowelable membrane and have encountered no problems yet.
Now,keep in mind,I have membrane showers out there that are near 20 years old so the jury is still out on the longevity of the product,However,I will say the stuff is tough and not near as labor intensive as doing a proper old fashioned Pan.(did I say old fashioned??? )
It will work,and it will work well I believe In this particular application.

While Bud and I do alot of commercial work,we are constantly encountering new architecturaly spec'd Products.Architectural Firms cannot spec a product that will not pass building codes so, you do the math John!!!
Pay close attention to the area where your walls meet your floor and seal this area heavily give it 3 coats if you have the time.
Now ,dont get me wrong,Johns Pan will certainly work and work well, It just is not necessary in this particular situation.Your slope is already there.

10-09-2002, 07:44 AM
Thanks again people. John, typically I'm a guy who goes for the full-on, over-built, by-the-book, anal retentive approach to almost everything. But I've been convinced to go with the method recommended by Bud, Todd , and KW.

You don't have to admit to anything however. Your legend is intact with me.

I've got a lot of work to do to finish this bathroom. There's been nothing simple about this remodel (read rebuild). Obstacles everywhere! My furnace duct routs through the top quarter of the bathroom ceiling, and the plumbing and toilet rough-in were positioned so that I had to work hard and stick-build an acceptable south wall. All electrical work had to be redone, and I had to drill through my brick exterior for an exhaust duct. Ever use a Hilti? A big one? Every thing in life should work like that tool!

When I'm done, I'll post some photos for you guys to review. I'll get close ups so you can grade my shower/tile work. Thanks again!

Bud Cline
10-09-2002, 03:53 PM
In this particular situation you'll be fine.

The prison job I just completed had four showers done in this fashion. The last jail I did three years ago was done like this, four showers there. The last two motels I did each had ground level rooms with some standup showers (eighteen in all if I remeber correctly) all done like this.

I have done plenty of residential basement showers this way over many years. It is a proven method.

In fact this isn't much different than the KERDI method that is coming on strong these days, same concept basically and John loves that.

John Bridge
10-09-2002, 04:07 PM
What legend?

I'm devastated. :D