No more pre-Slope? - Contractor Talk - Professional Construction and Remodeling Forum

Mellison · 10-27-2009, 07:17 AM

So I got to thinking,

As new building materials become available should we be re thinking older methods?
Here is my question, feel free to add whatever you like:

With the advent of waterproofing membranes ( Laticrete 9325 Etc). What are your thoughts for a custom shower pan with no pre slope in lieu of a proper application of a water proofing membrane applied prior to tile installation?
I have been applying the Laticrete as an extra precaution and it sort of dawned on me that the pre slope may no longer be necessary.
Also, I was never very confident that all or even most the moisture in the pan would find its way to the weep holes. I just pictured alot of that moisture being stagnent.

Lets say you:

pgc555 · 10-27-2009, 08:00 AM

Get ready for a flood of ideas about this one. You know that I went through alot of "slainin" when I brought up this subject. I can't wait to hear the responses. My opinion, the topical liquid water proofers have advanced to a level that we should be confident in using them. The whole idea is so that the water, as you say, never gets INTO the base. The sheet membranes are doing the same thing,water proofing the pan just under the tile install. I will sit on the sidelines and watch this thread.

wizendwizard · 10-27-2009, 09:35 AM

Most people follow the old saying "You can't teach an old dog new tricks".

With that being said, most setters have their way of doing things and they are set in that way and will never change. They may try new products but they tend to rely on what they KNOW works.

Its like Norm Abrahms flannel shirt, its always worked for him. Why should he change to golf shirts now?

TileLady · 10-27-2009, 02:43 PM

Waterproofing aside, how is the excess water going to get to the drain? Eventually it's going to just start hanging out. Doesn't make any sense to me. The water needs to go somewhere. Sinks and tubs are waterproof but are sloped to direct water flow. My 2 cents.

Splinter · 10-27-2009, 03:33 PM

If you're just slathering 9235 on the top of the setting bed, there's a good chance water will still find it's way into the mortar bed and down to the weep holes. Around the drain itself is the most likely place. A preslope ensures whatever gets to the liner will be directed to the drain.

If your surface waterproofer can have a guaranteed seal to the drain, then certainly the liner and preslope arent necessary. How do you get a good seal to a typical clamping ring drain?

If you havent seen the Kerdi shower, you need to head over to Schluter's website and take a look... The drain gets glued into the p-trap (or in PVC-free NYC, you could Fernco it) and it has a proprietary bonding flange that accepts the polyethylene Kerdi membrane. There's no "weak link" in the design for water to ever find its way through.

If you want to watch one go together, I'm doing 3 here in Nassau County over the next few weeks.

One more thing to add, and it's personal opinion.... I dont like the idea of a liquid membrane over the setting bed in a typical liner shower. Water will get in, but just around the drain.. It will weep through the bed dampening it thoroughly, and that initial amount of water will stay there for the life of the shower. Without the liquid surface membrane, any water from the daily showers that soaks through to the setting bed may "flush out" the moisture from the day before. Just my $.02

Mellison · 10-27-2009, 03:54 PM

Quote:

Originally Posted by Splinter

If you're just slathering 9235 on the top of the setting bed, there's a good chance water will still find it's way into the mortar bed and down to the weep holes. Around the drain itself is the most likely place. A preslope ensures whatever gets to the liner will be directed to the drain.

If your surface waterproofer can have a guaranteed seal to the drain, then certainly the liner and preslope arent necessary. How do you get a good seal to a typical clamping ring drain?

If you havent seen the Kerdi shower, you need to head over to Schluter's website and take a look... The drain gets glued into the p-trap (or in PVC-free NYC, you could Fernco it) and it has a proprietary bonding flange that accepts the polyethylene Kerdi membrane. There's no "weak link" in the design for water to ever find its way through.

If you want to watch one go together, I'm doing 3 here in Nassau County over the next few weeks.

One more thing to add, and it's personal opinion.... I dont like the idea of a liquid membrane over the setting bed in a typical liner shower. Water will get in, but just around the drain.. It will weep through the bed dampening it thoroughly, and that initial amount of water will stay there for the life of the shower. Without the liquid surface membrane, any water from the daily showers that soaks through to the setting bed may "flush out" the moisture from the day before. Just my $.02

Yes,
The seam around the drain is definitely the weakest link.

Just a thought, Even with the pre slope, I can imagine alot of moisture staying in the pan. With No heat and no air flow I can imagine a constant level of moisture.

Alex,
I would like to take you up on your offer to see a Kerdi installed.
I have wanted to see a kerdi system in person for a while. However, I am out of town for vacation starting late next week so it may not be possible.
I will shoot you a PM around late Novemebr to see if it is still possible.
Much appreciated,
Mike

angus242 · 10-27-2009, 04:41 PM

Quote:

Originally Posted by Mellison

Alex,
I would like to take you up on your offer to see a Kerdi installed.
I have wanted to see a kerdi system in person for a while. However, I am out of town for vacation starting late next week so it may not be possible.
I will shoot you a PM around late Novemebr to see if it is still possible.
Much appreciated,
Mike

Mike,

If Alex is offering, I highly suggest you take him up on it. After a session on what Schluter products do and how they can benefit a bathroom remodel, you should be sold on the concept. Waterproofing is a big deal to me and has brought closing bathroom remodels to a new level. When I do my presentation on how we remodel bathrooms, it pretty much sells itself. However, I don't just use it as a marketing tool (although it's a very good one). I really believe in the concept of w a t e r p r o o f i n g.

There are a lot of products out there now that can help you achieve this, not just Schluter stuff. But the point is properly controlling moisture in a wet environment. Do it!!!!!!

Splinter · 10-27-2009, 06:27 PM

No problem-o.... I'll put you to work hanging the Kerdi membrane, so bring your work pants.

I already had a few dozen Kerdi showers under my belt, but I went to the Schluter School down at the CTEF in South Carolina a few weeks ago anyway. I picked up a few new tips and tricks, got a few free bags of DitraSet, and drank beer with a bunch of the trowel-monkeys who are regulars at the John Bridge tile forum. I'll PM you my contact info, get in touch when you're back from vacation.

jarvis design · 10-27-2009, 06:32 PM

I think once you see Kerdi installed and understand how it works, you may never go back to ANY other method!!
Some people here complain about the cost - What does it cost to have a shower fail??

The only challange I face when selling showers with Kerdi is if the customer has not heard about it before - it takes me 10 minutes more to sell the job!! We're in luck here though, good ol Mike Holmes uses it on his show and a lot of people in this neck of the woods watch his show.

Oh, one more thing, see if you can get into one of Schluters Innovation Workshops - well worth it!