Replies

1. 
   27sean | Jul 05, 2002 01:51am | #1

   CPE/PVC will last longer, the stuff will last a lifetime and then some. Hot mopping is pretty much guarenteed for 15 years but routinly I have seen it last 30 years.

   Hot mopping is usually subbed out to a specialty contractor.

   Personally, I prefer the PVC/CPE liners. They last longer, are easier to work with, I can do it myself, doesn't stink, not messy etc.... CPE is easier to work with but it is not as easy to get. PVC is pretty much anywhere, even some Home Depots have it. Some people will say that the PVC liner will harden to the point of cracking because of the plasticisers in it but I have never heard of this happening. I have talked to a guy who has been using PVC liners in showers for over 30 years and still does to this day who has not had a single failure so I would say it is safe to use.

   Another important item is making sure that there is a preslope mudded under the pan. This will prevent water from just sitting on the pan and causing mold/mildew. Some guys try to slope the hot mop towards the drain instead of using a preslope but most of the time they just slap that stinky stuff in there and get out ASAP.

   Either method will work just fine as long as it is done properly.

1. 
   crabbyhammer | Jul 05, 2002 10:14am | #2

   Thanks Sean,

   Here's another question. It's going to be a fairly big shower and the woman wants a small built in-tiled seat or bench in the shower, how do I deal with that ? Do I wrap the entire seat in the membrane ? Or do I just wrap the edges ? I'm very confused.

   Thank you again

1. 
   KARLSTER | Jul 05, 2002 02:50pm | #3

   Check out the fold down seat made by ?steammist.  It should eliminate a lot of additional framing, waterproofing and tiling.  I found it on a website that I think is called bathclick.com.

1. 
   crabbyhammer | Jul 05, 2002 06:27pm | #4

   Hey Karl,

   Thanks for the tip, but it has to be tiled bench. Any advice on waterproofing the bench ?

   Thanks, Crabby

2. 
   27sean | Jul 05, 2002 06:38pm | #5

   first build the shower as if you weren't putting in a bench, then right before you tile, you put the bench in.

   Build up the bulk of the bench with either brick or block and then mud it. It usually helps to use a piece of plywood for a mold.

   Example, if you want to put in a corner bench then build up the bulk of it with bricks and then cut a piece of plywood that is the same dimension as the front of the bench. Hold it up against the walls and then just fill it up with mud. You can also do this with out the bricks or block, they are just used as filler. Make sure that the top of the bench is sloped so the water runs off of it and doesn't pool.

   Then just tile.

   There is no other waterproofing needed since the bench is built inside a shower that is all ready moisture proof. Any water that gets behind the bench and through the walls will just run down the moisture barrier on the wall, into the pan and down the preslope into the weep holes on the drain.

   Another cool thing about this system is that even if you have all ready tiled the complete shower you can still add a bench like this the same way.

   If you are using the thinbed method then make sure that you have a moisture barrier (15lb felt or 6mil poly) behind your cement board on the walls. Do not use green board and do not use mastic, use white thinset, modified or unmodified depending on the type of tile you are using.

   Have Fun!

2. 
   Scooter1 | Jul 05, 2002 07:52pm | #6

   Hot Mop or Vinyl? Age old question.

   Sean is right. Hot mops here in SoCal are the rage. 80% of the showers are hot mop. Vinyl is used for new production work and high end showers.

   Hot mops consist of a guy in a stinking Toyota truck building up at least 3 layers of 15 pound felt with hot tar smeared onto every nook and cranny. It is an awful, stinking, hot, disgusting job, but the average small shower can be done in about 30 minutes. Cost is about $150.

   Vinyl comes in 4,5,or 6 foot widths and must be seamed using special cement. It is laid onto the shower floor and up the walls onto the blocking, where it is bonded to the blocking with roofing cement, butyl caulk, or NobleSeal 150 and stapled at the top. The stuff is not cheap, and the average shower will run a couple hundred dollars in materials. It takes me about an hour to lay the vinyl membrane.

   For a bench, Sean is right again, but I do it a bit differently. Once the pan is in, I build the bench out of 8" block right there on top of the pan, then add some lathe and wall float on top of it. No waterproofing necessary. Just tile away. Any water that gets on it will go right down on the pan. Pretty nifty idea huh?

   I would like to take credit for it, but John "the Mudmeister" Bridge called my attention to the method. Here is a thread on how to do it:

   http://www.johnbridge.com/vbulletin/showthread.php?threadid=1354

   Not into a building a custom bench today? Well then try "the Better Bench" a prefab bench that installs with screws onto your CBU. Here is a link for the product:

   http://www.artistictile.net/store/betterbench.html

   Hope this helps guy.

   Regards,

   Boris

   "Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1927

1. 
   crabbyhammer | Jul 06, 2002 07:52am | #7

   Boris,

   Thanks for writing with the great tips. I still have a few questions.Is block or brick the only way to build a shower bench ? Is wood an absolute no-go ? When you say block, do you mean cinder block ? If I use cinder block and mortar to build the wall of the bench how do I finish the top ? Do I include framing to hold up and provide nailers for cement board ? Do you have to attach the block bench to the walls in some way ? And do you need to cold tar the edges- vertical and horizontal edges where it meets the back and side walls ? I'm sorry if these questions are a drag but I just want to get it right. Also, on a different but related subject...after the membrane has been pulled over the threshold is it O.K to nail cement board to the top and sides of the threshold ? That part is really confusing me too, because in all of my research I've found that most people really stress the importance of not nailing below a certain height. If you get a chance give me a shout. Also, thanks again to yourself and Sean for all of the great info.

   Crabbyhammer

1. 
   glenburn | Jul 07, 2002 06:43am | #8

   Well, let me throw in my 2 cents worth.  We just tore out our shower in the master bathroom - we bought an 8 year old house 4 months ago.  The shower was tiled over 1/2" cementitious backer board which was over 1/2" green board.  The entire thing was faced with 4" ceramic tile and grouted with regular ceramic tile grout (rigid).

   As with every tiled shower that I have ever seen, the grout had cracked in the corners.  I have come to the conclusion that anytime one has two walls meeting at a 90 degree angle, a crack will develop in tile grout, period - no exceptions.

   After being in our house for a little over a month or so, my wife started having difficulties sleeping - not like her at all!!!  Then she started complaining about waking up with headaches (never heard that line before).  Finally, she said that she noticed a peculiar odor in the master bathroom (before I got to use it).  After listening to this for a week (may be 2 - I don't remember exactly), I was finally talked into cutting out a piece of drywall next to the shower curb.  When I removed the piece of drywall a definate odor was noticed.  I shined a flashlight into the cavity - BLACK!

   We immediately tore out the entire shower and found a black mold or mildew.  It was concentrated near the corners of the shower where tile grout had cracked and moisture had infiltrated.  Surprisingly, at least to us, there were places where the mold/mildew had gone 5-1/2' up the wall cavity!!!

   I've been the hot mop route.  All it took was a failure or two to sour me on that method - never did like the stink either.  Sheet goods?  Well, I've worked with them in other applications - they have their limitations and special problem characteristics.  Generally speaking, I avoid them.

   Right now I'm rebuilding our shower with cementitious backer board.  On top of that I am using Sealoflex CT waterproofing.  It's not the neatest material to work with overhead or on a vertical surface (it sags and drips annoyingly), but it is both moisture proof and vapor proof.  All joints are polyester fabric reinforced and saturated with Sealoflex CT.  That sucker is not going back to where it was, ever, if I have my way about it.  We will be tiling over it too.  The Sealoflex CT is an elastomeric material.  As I am a factory certified applicator for Sealoflex waterproofing systems, I have used it outside on balconies (love it there and so do my customers).  This is my first attempt at waterproofing a shower though.  Special care needs to be taken to vent the heavy vapor as it is solvent based (naptha). 

   Generally speaking, I'm pleased with the results.  The Sealoflex CT is not inexpensive.  It is also too labor intensive for the average house.  An upscale shower though - I might be talked into doing one at $7/sq. ft..  That's a chunk;  however, the bottom line is a problem-free, waterproof shower.

   By the way, I won't be using tile grout in the corners either.  I will probably go with one of the polyurethanes or silicone compounds.  If the corners are going to move no matter what I do (and every engineer that I've talked with assures me that they will), then I sure don't want to use a rigid material for a grout as it will be guaranteed to crack somewhere down the road.  Rigid grout in the corners just doesn't make sense - at least to me - and yet that is all that I've ever seen in tiled showers and bathtub surrounds!  Of course I will use regular tile grout on the flat walls up to the corners - I've not seen those grout lines crack normally - just a thought for you to ponder.

   Well, that's this greybeard's two cents worth. 

   Good luck,

   Cliff. Johnston

   Granbury, TX