Tub surround walls

[Meshell_45]

Hi I have been reading all the valuable information on here. I have a severe allergy to mold and I have a concern about my walls before tile goes up. The cement board is resting on the lip of the tub and I am concerned that it will cause the tub to crack with the expansion and contraction of the acrylic tub and hardibacker. Is this something that needs to be fixed before tile? Will it crack the tub or cause other damage? I hate to have them redo it...is there an easy fix? I already have the corners done with hydrobarrier and their fiberglass mesh strips. I got kerdi fix for that gap but there is no gap. Also if I do kerdi fix between tub and cement board on floor will 100% silicone adhere to that between tile and tub after its laid? I called laticrete and they said it would...but can't be too cautious with my allergy!! Thanks so much!!

 

[Jadnashua]

It is not uncommon to end the cbu at the tub tiling flange rather than coming over it which often would cause it to bow out. But, it should not be tight down to the horizontal surface of the tub. You could use a strip of the mesh and the waterproofing to seal that joint, with only enough on the tub so that the tile would eventually cover it. KerdiFix is great stuff, but if I were going to use it for that, I'd want to use a strip of Kerdiband, and use the Kerdifix to adhere it to the tub, and thinset to adhere it to the wall with the cbu.

If I were really concerned with mold, I'd consider coating the entire wall surface with a waterproofing material...cbu is not waterproof, just not damaged by water.

Did they install a vapor barrier behind the cbu? (Hardiebacker is a type of cbu). If not, then without removing it, you really should consider a topical waterproofing. That could be a sheet like Kerdi, or the paint-on waterproofing material you used in the corners. If you don't have one, go to a good paint store and pick up a wet film thickness gauge and ask them how to use it properly (well, hopefully, they know!). It is crucial to check you have your liquid water proofing material applied at the proper thickness, and even when using the approved roller, how it is applied will vary considerably depending on technique. Essentially a wet film thickness gauge has some stepped fingers. You press it onto the just painted surface perpendicular to the surface, and see which fingers (steps) are coated. The last (highest) step that is covered with the material (the next ones being dry) indicates the thickness of the material. It MUST be between the min/max specified. Do this in more than one place, and adjust your technique if it is not within the proper range.

 

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[Standardairconditioner]

The cement board is resting on the lip of the tub

Stop using materials that aren't water resistant.

Cement board is popular because it is an old fashion norm, but it is porous and will contain water when it does.

Cement board is heavy to handle, cumbersome to cut, and expensive to waterproof, assuming it is even done right.

Waterproofing is easy when you use products that don't require "waterproofing".

Lightweight and easy to cut Schluter Kerdi-board is not only an entire wall replacement, but requires no additional waterproofing. The product saves tons on labor and material costs.

Watch some videos about installing the product.

Also if I do kerdi fix between tub and cement board

Again, you are pulling your own hair with the wrong use of a good product.

Schluter Kerdi-Fix is not caulking. It is the adhesive for Schluter Dilex (look that up).

A proper Schluter wet-room is caulk-less.

My home Schluter wet-room is made with porcelain tiles and epoxy Bioblock grout. My showerwalls "self-wash" themselves as I shower. I never wash nor squeegee them. It's been a few years, I still haven't seen any mold and mildew pop up. I guess if I start seeing something, I'll try to find the time to pass a sponge over it.

 

[Meshell_45]

I have watched the videos. They don't carry kerdi board anywhere near where I live. I couldn't find a place to buy a few sheets online. I used laticrete. Isn't the kerdi strip same as the latacrete fiberglass mesh?

The hydrobarrier does not bond to acrylic they told me. That is why I was thinking kerdi fix and a line of the fiberglass mesh. The closest home depot is almost 2 hours away and it's my only shower.

Yes the cb is touching the tub. It is supported.

Thank you for your help. Is kerdi fix and the fiberglass mesh to bond to tub not going to waterproof it?

 

[Meshell_45]

Even the home Depot almost 2 hours away has the strip but not the board...I wish it was more widely available. I have read good things about the hydrobarrier and it does not specify a particular paint roller. I am using a trough and doing things coats so it doesn't get too thick. Just wanted something to bond the fiberglass mesh to tub and subfloor joint to tub for extra protection

 

[Standardairconditioner]

Even the home Depot almost 2 hours away has the strip but not the board

That's really funny because the Schluter Kerdi-Band strips are used to install the Schluter Kerdi-Board. Home Depot is a Schluter retailer, and if they don't have specific parts on hand, they can certainly order it.

I would call Schluter and they will tell you if there are any local contractors they can recommend. Schluter products are marked up enough so that contractors will still have an incentive to sell you just the material. Schluter has a published retail price list, and no retailer or contractor should sell above these prices. Home Depot does sell at the published retail price list.

Schluter will never condone their products when you use them in other ways than intended, which is what you are trying to do. Kerdi-Band strips are not made to be used alone. Kerdi-Fix is not a caulk.

Build your bathroom the Schluter way, and your bathroom will never see mold in your lifetime. The rest of your home will fall apart before the bathroom does.

 

[Meshell_45]

Yes I thought it was strange too but I just checked their online inventory because i had seen the roll of mesh. I seen where you can order 10 sheets online but that's all I could find. Is it heavy can it go over cement board? I don't want to pay someone to take down what's already started. I guess I can just do best I can with what I have and hope for best and save for schluter if it fails. My main concern was the cb contact top of tub. Thank you

 

[Meshell_45]

And yes also I was trying to install the laticrete mesh fiberglass same as the schluter. I thought that is what the schluter roll was.

 

[Standardairconditioner]

Yes I thought it was strange too but I just checked their online inventory

Stop buying home materials online. Make a phone call to Home Depot and work with someone that will order it for you. Or a local contractor that can probably sell to you for less.

Is it heavy

Re-read what I wrote in #3. It would be silly if I repeated the same text in the same thread.

can it go over cement board?

"Kerdi-Board" is a wall replacement. Plain "Kerdi" is the thin membrane that goes over whatever you want, but costs just as much as "Kerdi-Board" and requires much more time to install. Note: You do not remove the tub to install Kerdi-Board, you only need material from the tub and up to the ceiling.

I don't want to pay someone to take down what's already started.

Because you want cement board that will hoard water and mold in a few years? You might as well save more dollars with unsanded grout for the tiles too. I really hate grout lines that darken with mold. I love how mine are teeth white and mold-free after years of use and zero cleaning.

 

[Meshell_45]

I have hydro barrier on the cement board so it shouldn't get moisture and using laticrete spectralock. And yes you are right i will never order materials like I have online again. I ended up probably spending more money.

So is the cb contacting the tub ok and putting the fiberglass mesh with kerdi fix at that Junction for added protection going to work?

 

[Jadnashua]

Kerdiband is waterproof, it is not a mesh. The mesh you installed is for reinforcing a seam, but in itself is not waterproof. If you don't use a wet film thickness gauge, you are unlikely to be able to judge by yourself how thick the coating applied is. They are cheap (less than $10), and you should be able to find one at a paint supply store.

As I said, if you had not used a vapor barrier behind the cbu, you should install a waterproof layer on top of the board. My preference is to do that, since very little is then possible to get wet. To avoid mold, you need to break the triangle of either water, food, or the mold spores themselves (almost impossible to eliminate). So, doing what you can do to keep things dry, like using a waterproof topical material, is the first line to preventing mold. Tile are not considered the waterproofing layer and moisture will get behind them. Stopping it at that surface is your best bet, but it must be installed properly. FWIW, HardieBacker is classified as a fiber-cement product. THe fiber in it can contain up to 15% cellulose (paper fibers), i.e., mold food.

 

[Meshell_45]

Oh my....thank you and no did do lots of research and did not use a vapor barrier. I did not see anything on the thickness. Hydro barrier website says when you can't see the substrate it is covered...thank you. I will call them today as I only have a very thin layer and doing the rest tonight.

 

[Standardairconditioner]

When DIY's mix a mashup of different materials like this, a great deal of "research" is needed to make sure things will actually work. In the end, there is no way to do things by the book, other than personal suggestions that vary from each individual's experience. Homewoners hope for the best that nothing fails months or years down the road, on top of the "research" time spent on "What-ifs" and "Maybe".

For those that don't like to gamble, Schluter is one of those few manufacturers that have a complete material solution for ground-up construction. Not only do they eliminate all guess work, they tell you exactly what you have to do, and provide all the material to do it.

 

[Jadnashua]

See note 1 on page 3

http://www.laticrete.com/Portals/0/datasheets/DS-105.5.pdf

 

[Meshell_45]

Well my tub cracked...it's coming down. It's not sticking to the hardi backer in places. It's coming down. Lowes is the only store we have here within an hour...then Menard and home depot 2 hours almost. Lowes has the band. Is that as water proof as the kerdi board? They told me weeks for the board to get here. I can't wait that long...it's my only shower.

 

[Meshell_45]

I'm not DIY ing it I'm trying to find a way to water proof it. My contractor has never used any waterproofing. I researched and though just doing the laticrete is sufficient but I just learned that hardibacker is not 100% cb. I'm just someone crazy allergic to aspergillus and alternaria mold that is trying to make sure it's water proof...

 

[Meshell_45]

Yeah I seen the videos. The membrane applied over drywall...didn't look too bad...I'm sick about it...thanks for your help.

 

[Meshell_45]

And I'm not mad please don't run down my contractor. He has honestly done everything he can to help me. I have no doubts he'll fix it but he is old school and doesn't know anything about the newer waterproofing products. Super good guy and people make mistakes. Just trying to figure out where to go from here. And preferably with things I can get here. I can't miss any more work as I took off 3 days for that and my dog had his acl surgery. I just want my shower back

I have no doubts he will make it right and can. He is used to drywall and tile. He was under the assumption that tile and grout were water proof. He has even said he is learning stuff from me and is actually excited to learn new things, as I am in my profession. I don't know it all or I wouldn't be on here but I have done tons of research. I didn't even know lowes carried the rolls...there website sucks. And yes I did a lot online but like I said my dog just had major surgery and I am a cpa and tax season on top of my full time job has been overwhelming this year.

I had called the company about a crack in the flange and they said fiberglass repair like auto body and my contractor said same thing before I even told him what they said. I know he can fix it...he just knows nothing about the schluter/laticrete...not too many people are affected by a little bit of mold but as I have gotten older my allergy has been worse. Had some pretty bad exposure at work and only three people in the bldg were affected. 95 percent or better were not. He has used other old school methods that are much more difficult than the newer methods on like tile showers.

Like I said I just want to move forward from here...and appreciate your insight and help. Thanks again.

 

[Meshell_45]

Is the kerdi membrane applied with thinset over drywall good??

 

[Standardairconditioner]

Lowes is the only store we have here within an hour...then Menard and home depot 2 hours almost.

Because you already called Schluter System Usa, and they confirmed there are no other regional Schluter resellers or local contractors to buy material from?

My contractor has never used any waterproofing.

You hired someone that has never set tiles before to do tile work? Tile work in bathrooms and waterproofing are synonymous.

I researched and though just doing the laticrete is sufficient but I just learned that hardibacker is not 100% cb.

For those that don't like to gamble, Schluter is one of those few manufacturers that have a complete material solution for ground-up construction. Not only do they eliminate all guess work, they tell you exactly what you have to do, and provide all the material to do it.

I'm just someone crazy allergic to aspergillus and alternaria mold that is trying to make sure it's water proof...

Stop using materials that aren't water resistant.

He was under the assumption that tile and grout were water proof.

No and never. Tile and grout is purely cosmetic. Earth clay and porcelain are very porous, especially volcanic-styled tiles that looks like natural rock. They continuously soak and release water.

He has even said he is learning stuff from me and is actually excited to learn new things

You hired a tile setter that has to learn tile setting from you?

I didn't even know lowes carried the rolls...there website sucks. And yes I did a lot online

Stop buying home materials online. You can always make phone calls to stores and manufacturers that would have recommended local resellers and contractors to buy material from.

I had called the company about a crack in the flange and they said fiberglass repair like auto body

When auto body and chassis rust damage is repaired with fiberglass, the rust does not come back if and only if it never sees water again. This is why restored vehicles are garaged indoors and turn into Sunday cars. No automotive restoration shop will ever guarantee a fiberglass repair because it can't be guaranteed. Water eventually breaks down the glue in the repair, the rust comes back. In the case of a cracked tub, water will get through it, and plenty of empty space under there for mold.

he just knows nothing about the schluter

Schluter is one of those few manufacturers that gives free training with their regional schools and hands-on workshops.

not too many people are affected by a little bit of mold

Actually a lot of people are affected by any amounts of mold, as it is a proven health hazard. This is why manufacturers go through great lengths with products that stop mold dead on. I don't need reports and experts to tell me mold is bad. I can sense trace amounts and even the slightest bit will put me on a disinfection spree. That's why I love my Schluter bathroom that is mold-free after years of use without cleaning.