which waterproofing system for new shower?

[ratherbefishing]

Plumbing for my new bathroom is almost done. Insulating should go quickly. So, I'm on to thinking about the tile. The shower is 3x4', no tub; tile will probably go to the ceiling. I'll be making a mud bed. What waterproofing system do you guys recommend for a novice? I'd planned on Kerdi, after reading John Bridge's forum. Now I'm not so sure. Our local tile supplier sells Hydroment and Gold Plus. I've heard of RedGard, too.

I've tiled a couple rooms, but never a bathroom. Which system is the best bet for a novice?

Thanks!

[johnfrwhipple]

Plumbing for my new bathroom is almost done. Insulating should go quickly. So, I'm on to thinking about the tile. The shower is 3x4', no tub; tile will probably go to the ceiling. I'll be making a mud bed. What waterproofing system do you guys recommend for a novice? I'd planned on Kerdi, after reading John Bridge's forum. Now I'm not so sure. Our local tile supplier sells Hydroment and Gold Plus. I've heard of RedGard, too.

I've tiled a couple rooms, but never a bathroom. Which system is the best bet for a novice?

Thanks!

You mention you are making a mud bed. What type of mud bed? Has the plumber installed a three piece clamping drain and liner?

A troweled applied waterproofing product is the hardest to use in my opinion. Over a regular mud bed a sheet membrane is best. Over a fast setting screed mortar the liquids work great.

Do you have a tile selected? Many require modified thinsets.

JW

[ratherbefishing]

John,
All that's done so far is the framing and plumbing rough-in. The shape and dimensions don't work for a store-bought pan, so I figure I'll build it myself. Walls will be 1/2"(?) cement board. Tiles haven't been selected yet, but my wife is leaning towards a subway shaped ceramic. Shower floor tiles will be smaller to accomodate the slope. The fella at the tile store recommended Gold Plus, a roll-on membrane.

Oh yeah, I'm the plumber, too.

[jadnashua]

If you chose Kerdi, their recommended wall covering is drywall, larger sheets, fewer joints, cheaper. Since a properly built membrane shower keeps the moisture on the top side of the membrane, the drywall stays dry, and works fine. If it leaked, while the cbu wouldn't care, the structure would have problems, so leaks are a problem regardless, so choose whatever makes you feel happy, and don't look back second guessing. CBU works, too, but remember to wipe it down with a wet sponge first to take off the dust and to help prevent it sucking all of the moisture out of the thinset making installation harder and giving you less time. Other membranes, follow the manufacturer's recommendation on wall structure. A sheet membrane is sort of like putting up wallpaper, except it isn't critical matching patterns and an overlap is okay (you need one, whether it is the main sheet, or the manufactuer's banding material that can be added after or before the main sheets are applied, as long as you get the specified minimum overlap). The key with any membrane sheeting is to get the thinset mixed properly, and to use the proper premium type specified, and last, to pull a bit back off to check for proper coverage. The Kerdi drain is quite flexible as the square holding the grate can be easily moved during tiling to minimize cuts around it. My last one used 2x2 tile, and I was able to just cut four of them out of the mat and slide the center to perfectly align the gap...very neat and easy.

[johnfrwhipple]

If you chose Kerdi, their recommended wall covering is drywall, larger sheets, fewer joints, cheaper...

Cheaper is the plan of attack for most builders, developers and such. Kerdi appeals to that market. If you refer to a TTMAC or ANSI specifications guide you will not find drywall listed. Please don't use drywall. This is horrible advice and outside industry standards.

I love roll on membranes and have privately test many. I have build showers with Custom's Red Guard, Mapei's HPG and Aqua Defence and Latecrete's Hydro Ban. My favourites are the Aqua Defence and Hydro Ban.

The most important thing to remember is that proper coverage rates are realized. A typical gallon container will net about 60 square feet when applied in two coats the Gold Plus is listed for 45 it says here on the PDF Data Sheet. The thickness will be around 20 mil or roughly 2/3 the thickness of your credit card. If your the plumber do I assume then you are the waterproofer and tile setter?

Liquid membranes are very easy to install and like setting tile fail mainly do to improper installations techniques. Bond breakers like dust will make for a poor installations. We always tape our seams with mesh tape and thinset before installing any liquid waterproofing. Before installing we always wash the walls down to insure no dust is present. If you plan to use GoldPlus as the primary pan waterproofing you should check the proper procedure there. I'm a big fan of extra reinforcement at the drain tie in point. Mapei and Noble Company both make products called Drain Flashings for this.

Using a liquid membrane over a fresh mortar bed can be tricky. Unless you have access to a rapid setting mortar like Mapei's Mapecem Screed Mortar Fast Setting you need to wait while the mud bed cures and most of the moisture has left the install. With a traditional 4-1 mix that can be 4 weeks. With a product like Latecrete's 3701 you can Hydro Ban over top in 72 hours and with Mapei's Mapecem Fast Setting Screed Mortar as fast as 24 hours.

You could also simply build a traditional shower pan with a liner and take care addressing the pre-slope and weep holes and have a solid shower.

Time is money. Everybody wants more time and more money.

Choosing the proper technique often comes down to product selection in your area and local acceptance and plumbing codes. A quick trip to city hall will shed a lot of light into what the inspector will want to see. Are you pulling permits for this project?

Sheet membranes are many. There are sheet membranes from Jaeger, Prottego, Wedi, Dal Tile, Schluter and Noble Company and I'm sure even more I have not seen. All are approved for use in showers as a primary waterpoofing material. Jaeger makes the product for Wedi and are one in the same. Noble makes the one for Dal Tile. The Noble Companies Noble Seal TS is my favourite - 30 mil thick or as thick as your credit card. The Jaeger and Prottego membranes are 20 mil - much like liquid membranes. The kerdi membrane is only 8 mil or roughly 1/4 the thickness of your credit card (This I believe is the bare minimum of thicknesses).

The major advantage of a sheet membrane over liquid is Time. If you can not get Mapecem then you need to wait. Most professional will wait about 3 days before covering a mortar bed with a sheet membrane but some do in as little as a day. Mortar beds shrink as they cure and will stress the floor to wall connection - this is yet another reason I love the Mapecem product so much as this shrinkage is way smaller. With Noble and Kerdi you have a chaulking type product that makes the seam connection - relying on thin set to make a waterproof connection is silly. Our homes move and these connection points should have a slight chance of give.

Liquids and sheet membranes both offer up flexibility.

This is a lot to digest and often over whelming - First plan out the design, your tile selection. Houzz.com is a great place for inspiration.

Once you selected a look and tile ask the manufacture which setting materials and sealers they recommend.

Now you have some more info to work from. If your tile is large format, glass, natural stone or higher quality porclean most likely you will find a recommendation of modified thinest. I have yet to find any company endorsing the use of non-modifed thin-set other than Schluter. I think this falls into the same reasoning Jim outline in his post. Cheap and economical.

If your setting the tile yourself you will like the higher ititial grab of modified thin sets and the anti sag mortars make setting large format tile night and day easier than a cheap non-modfied thin set. My opinion - and that of most tile setters in Vancouver I have asked.

If you are the tile setter consider as well working with one supplier. Laticrete and Custom have some of the best systems and warranties for you. Mapei a close second.

There is lot to learn and much debate online. You will find most "Helpful Posters" in fact do not install for a living - they "Sell".

Any online advice should be followed up with an email or phone call to the supplier.

Flood test that shower. Always self inspect.

Protect the waterproofing from harm after it's done.

Waterproofing a shower is not something you can almost do perfect. When it's perfect. It's good enough.

JW

[dlarrivee]

Has anyone tried to use an airless paint sprayer to apply these liquid membranes?

[mtcummins]

If you're using the Schluter products (Kerdi), you could get a 48x48 Schluter shower pan and cut it down to size. They're made to be cutable, so you'd just take 6" off 2 edges to get your 3x4 pan. This would save you the hassle/dry time of doing a mud bed.

There may be other cut-able pans on the market, I'm not familiar with them if there are. These Schluter pans require Kerdi over them and a Kerdi Drain to make a water-tight system. Maybe you can use other products with their pan, but I don't know about that, I just use the complete Schluter system, as it was designed to be used all together.

If you're going that route, you might as well just buy the whole shower kit and get everything in one shot. These generally run about $600.

Lemme save JW the hassle, and tell you right now that he thinks they're junk, they're overpriced, they're marketing hype, that Jim and I are getting paid by Schluter to hock their junk, etc. Its all bullshit, but that's what you're about to hear.

Choose the product you like (all of the ones JW likes are good products as well, if installed correctly), and install it properly, and you'll be fine.

[jadnashua]

IF the waterproofing membrane was also a wear surface (it is most certainly isn't), then thickness might be an issue. ALL are designed to be covered up with a wear surface, and MUST be protected prior to that happening. GoreTEx (TM) is MUCH thinner than Kerdi, and it works fine - because it isn't the wear surface - you NEVER see it as a top layer in clothing. Not saying GoreTex (TM) is a suitable tiling substrate, but this thickness argument just doesn't hold much water (pun intended!) with me. In a real situation, a thicker membrane can make corners harder to keep nice and flat. They ALL can get a hole poked into them, and if it does, it's poor workmanship. They ALL can be fixed, if that happens. ALL of the available membranes that have been approved (Kerdi has, along with many others) include a phrase like 'installed per manufactuer's instructions' that's part of the approval. Schluter recommends drywall, Kerdi is an approved method of waterproofing. Now, if you have a local code that doesn't allow it, it will work equally well installed over cbu, deckmud, a mudded wall, etc. It is NOT approved for use directly over wood, though, but most (all?) aren't. Choose whatever you prefer, but some people's rants against any one particular product are one person's rant, not the industries.

[mtcummins]

I dunno Jim... thicker is always better in my experience...

Thicker TVs make good designer statements and hold up better to their secondary use as a dartboard (when your team is doing poorly)
Thicker underwear are nice and comfy
Thicker glasses make for better vision (and more comfort on your face)
Thicker phones fit in my pocket better
Thicker skulls make smarter people

C'mon Jim. Thicker is better. Get up to speed.

[ratherbefishing]

JW, I am the tilesetter, plumber, framer and electrician on this project. So I'm learning a lot. The framing is straight and square, tho there may be a few more pieces of wood than an old pro woulda used. The last piece of Romex I ran looks better than the first, but they all passed inspection. I'm kinda proud of the copper in the crawl space. Looks almost like I knew what I was doing. But once I'm all done, all anyone will see is the tile. (Cr@p, I think I mighta made myself a little nervous there.)

Time isn't that important, as I'm mostly working on the weekends. Money always counts, but I'll pay a little more for DIY friendly, if not idiot proof.

Mike

[johnfrwhipple]

Has anyone tried to use an airless paint sprayer to apply these liquid membranes?

One guy chimed in here to say how easy it is but I have never tried it. I would think the cleaning of the tool would be more labour intensive than the waterproofing by itself.

7-8 showers is the target in commercial installs per guy per day.

If your doing multiple showers in one location then it might be worth trying. Me and David might hit two or three stops a day and most times the bathrooms are at different stages.

JW

[johnfrwhipple]

JW, I am the tilesetter, plumber, framer and electrician on this project. So I'm learning a lot. The framing is straight and square, tho there may be a few more pieces of wood than an old pro woulda used. The last piece of Romex I ran looks better than the first, but they all passed inspection. I'm kinda proud of the copper in the crawl space. Looks almost like I knew what I was doing. But once I'm all done, all anyone will see is the tile. (Cr@p, I think I mighta made myself a little nervous there.)

Time isn't that important, as I'm mostly working on the weekends. Money always counts, but I'll pay a little more for DIY friendly, if not idiot proof.

Mike

What shape is the shower? What type of tile do you think you will use?

Are you using a regular drain or linear drain? Have you seen the tile top drains?

Do you plan to have recessed shampoo niches?

Steam?

All factors in choosing the best products.

JW

[johnfrwhipple]

...Schluter recommends drywall, Kerdi is an approved method of waterproofing...

Kerdi is a recommended method of waterproofing.

Drywall is not permitted in wet zones. You might apply Kerdi over the backsplash near your sink or behind your stove but not in your shower.

In Europe Kerdi DS is used for primary wet zones (showers) and steam applications. Kerdi is used elsewhere.

Many liquid membranes also list drywall as an acceptable substrate but you would be equally outside of industry standards if used in a shower.

Best thing to do is to phone the TTMAC or purchase their specification guide. Drywall is listed only in non-wet zones.

This is really just common sense and Jim you site the proper rules when you choose. I would imagine you have a specification guide handy. Why not open it up?

JW

[dlarrivee]

Here we go again.

[jadnashua]

The reason WHY drywall is allowed, is it is NOT in a wet area when Kerdi is properly installed. There should be no vapor or liquid water that gets to the drywall from the wet area, therefore not a wet area.

From the Kerdi shower installation manual, it says solid backing materials for installing Kerdi, then, the section that describes what those suitable materials are (sorry, it didn't copy/paste with all the formatting, but it's all there):
Solid Backing Materials

Gypsum wallboard – ASTM C1396/C1396M

Cementitious backer unit – ANSI A118.9 or ASTM C1325

Fiber-cement underlayment – ASTM C1288

Fiber-reinforced water-resistant gypsum backerboard/underlayment –

ASTM C1278

Coated glass mat water-resistant gypsum backerboard – ASTM C1178

Portland cement mortar – ANSI A108.1B

Concrete

Masonry

So, pick one that makes you and your local inspector happy, but ANY of these are approved.