Tub surround walls

[Standardairconditioner]

I can't wait that long...it's my only shower.

You're not going to do anymore damage to your woodwork and framing studs if you nail up thick vapor barrier plastic so you can take quick showers temporarily as you figure this out.

You and your tile setter needs to stop and sit together and plan carefully how you will solve this without anymore "guessing" and "what-ifs". Your tile setter is not smarter than any manufacturer. He must do it their way. His experience helps, but does not overrule.

You made a mistake thinking that buying everything "online" was the solution. A "brick and mortar business" is called exactly that for a reason.

You seem too busy to make phone calls and visit other resellers, you may want to pay your tile setter to do that since he is certainly not working on your bathroom at the moment.

 

[Jadnashua]

If you decide to go with Schluter's Kerdi, they list 4-5 different backers that the membrane can be applied to, which includes drywall, and the existing HardieBacker could be left up and used as well. Laticrete's Hydroban sheet membrane (not their liquid) also has been tested and certified to work over drywall.

While you'll pay retail for it, Schluter will ship direct to you and you'd get it in a couple of days, if there are no other easy choices. Laticrete might as well. If you call Schluter, they may be able to tell you of a local tiler that has been to their training, and he might sell you some material as well. Their local rep may be able to help as well, especially with the guy never having used the stuff before, he might stop in and help out a bit, or at least be available to answer questions.

Tile directly over drywall is a recipe for disaster. Tile on Hardie, should be reliable. If you want to avoid any visible caulk, Schluter (and a few others) make engineered joint profiles that can go in the corners and between the wall and the tub surface. There are advantages to using a more modern system...Schluter's is entirely non-organic, and because the waterproofing is directly beneath the tile, very little to get wet which is one requirement for mold to grow. I highly suggest you get a good exhaust fan, and preferably one with a built-in timer or better yet, one with a humidity sensor that will turn on and stay on until the area dries out. Keeping things dry prevents mold. Panasonic makes some really nice, quiet, reliable units, and some of them can be ordered with a built-in humidity sensor, or you can replace the on/off switch with one (works, but I think having it up higher in the fan works better).

 

[Sponsor]

 

[Meshell_45]

I took off work today. By time morning came I was about to have break down. He came and could have diamond bit a space for wicking but put his fingernail and seen if laticrete adhered and it peeled off. He said it's not right, it's coming down. I knew he'd make it right but there is always that little doubt...but that's just from past experiences with less trust worthy people and he actually appreciates learning from what I have learned. I had to get the $115 a roll membrane because noone sells the board and I just didn't want to wait.It was within a 50 mile radius. You can't put a price on your health when you have severe aspergillus allergy.

My contractor was amazing and did excellent! He just isn't up on all the newer stuff. I'm telling you small town! We went to lowes and a contractor friend of his was there and had went to a their 2 day workshop. It's going to start growing here, Lowes also sent a few employees...it was 120 miles away lol. I still read good things about laticrete but I have also read kerdi has issues adhering to hardibacker. Being a person so allergic to mold, and quite knowledgeable from having to be, it irks me that hardibacker advertises as mold resistance when it's 10% cellulose!!!!

We ended up doing it over durock because even with a pipe leak...drywall and water is my very worst enemy! Thank you so much for your help!! And thanks for your tip about the shower. I have a huge roll of 6 mil lol. It's thinnest membrane mold can't pass through.

 

[Meshell_45]

I'm sure drywall would been sufficient but honestly drywall in a wet area with plumbing that you'd have to tear wall out scares the hell out of me. It's a sponge and mold haven that you can't safely or effectively clean mold off of.

 

[Jadnashua]

The installation instructions for Kerdi specifically say to wipe the wall down well with a wet sponge, to use a premium unmodified thinset (no organics, which for you is also a plus - a good portion of modified thinsets use latex in one form or another in them), and to check the coverage by pulling back a section to see if you got good coverage. The issue with HardieBacker is that it is VERY thirsty, and sucks too much moisture out of the thinset before you can get the membrane up unless you wet it first. If you do that, and use a quality thinset, it works very well. It's a learning curve and following ALL of the instructions, even those that may not seem important. As long as there's not liquid water dripping off of the backer prior to spreading the thinset (any backer, but Hardie is probably the worst), it's not too wet. The goal is to let the thinset be mixed properly with the desired flow characteristics and not be hindered by a good portion being removed by wicking into the board behind. In reality, it's not a bad practice to wipe any surface you are going to spread thinset on prior, except maybe for the actual waterproofing membrane itself, since it's not going to absorb water from your thinset.

Building a shower that will be a high performer and long-lasting isn't really hard, but is very detail oriented...you can't skip steps, especially if you're trying to mix products from lots of manufacturers...you don't know how they will interact. This is the reason why Schluter and Laticrete (and others) will only warrant they products when installed as a 'system' in the specified manner. While picking and choosing products across many manufacturers may work, it can be really hard to determine how best to utilize them, and then if something fails, it's finger pointing time. One manufacturer's system, one finger to point.

 

[Meshell_45]

Do you think thats why laticrete did not adhere to the hardibacker? After that the hardibacker came down, he never even tried bonding kerdi to hardibacker. We switched to durock. After I found that the "mold resistant" hardibacker had 10% cellucose. I had just read that someone else had issue with kerdi adhering also to hardibacker. So its laticrete and kerdi that have issues. Like I said being so allergic to mold, it irritates the hell out of me that Hardibacker advertises and does try and hide the fact that it made with organic fibers. Its water under the bridge now but I feel bad for my contractor but I too let him know that its not just laticrete, I read kerdi too had adherence issues. I think its junk and the advertising is misleading.

 

[Meshell_45]

Of course I have no use for anything with organic fibers that is absorbent anywhere near water source!!!

 

[Jadnashua]

When painting a waterproofing material on something like Hardie, it is often recommended to thin the first coat and consider it a primer...that way, it can cure properly before the moisture is sucked out of it.

They also don't have a huge peel strength. Schluter's Kerdibond adhesive once cured, is over 500psi of bond strength...totally different class of material. FWIW, the final bond strength of a material like Kerdi is in the order of 50psi minimum, and can easily be peeled back for days afterwards. Thinset doesn't reach full specified strength for 28 days.

 

[Meshell_45]

It's amazing stuff. Worth every penny to know I will never have to tear my shower out, that is turning out beyond beautiful by the way, for even a little bit of mold. Thank God for Schulter!!!! I think in the end it made it easier to tile too with smooth walls. So thankful for them and my contractor for not hesitating to know it wasn't right with the hardibacker and laticrete not adhering to it and replacing before it was too late. I am a lucky girl!! Thank you for all your help both of you!!!