Hardi board over drywall?

I had a contractor put up drywall and then hardiboard over it. Then the tile guy came by and said that was not done properly. What is the correct type of install for a bathtub hardibacker install please?

The tile guy also said that the hardiboard on the floor should have been laid with mortar. The contractor DID NOT use mortar but instead screwed it down. The tile guy said the screws should be 6" apart and not 12". Who is right?

The tile guy.

You can get the Hardi instructions on the james hardi site...print them out and show them to the contractor. Tell him you want it done by the manufacturer's instructions...or to extend the warranty for life! It can take anywhere from a few weeks or less to never for it to fail, but the odds are much less if done per the instructions. Actually, if there is a sheet still around, there's an instruction sticker on each sheet.

Hey Honeysuckle- the tile guy is absolutely right.

Do not proceed unless you redo the walls: vapor barrier behind the Hardi, corners taped, some folks even will use redgard ( a water proofing solution that you paint or roll on), then tile.

The morter between the subfloor and the Hardi is to fill the voids so that the surface that the tile is laid upon is flat. Hardi is then screwed or nailed with galv. roofing nails every 6".

THe good news is that if he screwed the Hardi into the wall studs, he can UN screw them so that you can re-use that Hardi.

This is NOT a disaster, just a speed bump. Don't stress over it, just re-do it.
Happy trails-

He did not use a vapor barrier behind hardi board. Will I be charged if I ask him to redo properly? He claimed tonight that he has ALWAYS done it this way and never had a complaint.

See all those little blue dots on the hardibacker? EVERY one of them should have a screw in it on the floor.

Other comments already made by others ...right on. This is fairly basic procedure. You see that several people had immediate comments. Your guy did not follow industry standard, manufacturer-specified procedures.

"I had a contractor put up drywall and then hardiboard over it."

Wouldn't it be more waterproof to screw or nail the cement board directly into the studs and leave out the drywall?

Also, is it possible to use Ditra directly over the drywall instead of cement board?

In a shower, you'd use Kerdi, a waterproofing membrane. Ditra is a decoupling sheet for floors. Ditra seams can be made waterproof (the sheet is by itself) by putting a band of Kerdi over them, overlapping the seam by a minimum of 2".

A surface membrane, such as Redgard or Kerdi, or Noble could be used instead of R&R'ing the Hardi, and installing a vapor barrier behind it. A surface membrane has other advantages, too, since the cbu wouldn't, couldn't get wet. SPecial attention must be paid to the bottom, especially since there is drywall in the sandwich.

James Hardy does not require a vapor barrier behind it in their instructions, but suggests it is a good idea. This is probably because the Hardi itself won't be harmed by moisture; they aren't warrantying the studs, only the Hardi. Industry standards for the shower system call for a vapor barrier, not the CBU manufacturers.

HoneySuckle said:

I had a contractor put up drywall and then hardiboard over it. Then the tile guy came by and said that was not done properly....

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Fix the floor. It's bad.

The walls can be left as is but that is not ideal. Lucky you, that your tile guy is thorough and professional.

The walls can be painted over with any liquid membrane. Search on Custom, Noble, Mapei and other company web sites. Redgard is the most famous. Your tile guy will confirm to you that any liquid membrane can be added on top. Or Kerdi, which is also a top layer membrane. Liquid membranes are also known as trowelable, so use that word if necessary when you shop or search.

I won't score any points for thoroughness if I mention you could leave the walls alone, but I do think it is important to say that the floor is the most serious thing. I wont's score any points among participants who want the record "for the future" to be clean of all confusing nuances, but I do think it is important to say that the floor is the most serious thing. There are a number of reasons that all add up that could justify why you could leave the walls as they are now, but all together they are still a weak argument. So, I don't wish to be taken to task for having said that you could leave the walls as they are.

You could also unscrew the Hardi off the walls and remove the drywall too, and then start over again with an extra inch of space added to your bath alcove. If it fits your tub's tiling flange, it is nice to have more space.


The tile guy said the hardiboard on the floor should have been laid with mortar. That is serious.

If not done, your floor tiles may show hairline cracks that are almost invisible and that many people don't care about. Perhaps your GC could let you visit all his previous installs and you can swing by and inspect them all.

There is no reason to let your floor tiles crack when they are not designed to be installed that way. If you wanted a mosaic made of cracked tile pieces, you would design it that way, with a regular width of grout line between the pieces.






David

David, while reading your post, I almost forgot how mad I am at that contractor. I've had two other tile contractors out and each one said the same about the wall job - shabby work, looks like someone was having a bad day etc.

I am going to call the original contractor and have a talk with him. I feel that he should have a chance to fix his bad work. He won't like it one bit, but I am not about to pay another to fix the mess he made.

Anyway, last tile guy said that the hardi-board should NOT have been placed all the way down to the tub. Is he right? He said this is why the hardi board is bowing. Original contractor claimed the bowing was caused by the joists. How is that possible? Last tile guy also pointed out a few things like where the board wasn't screwed down, and where it looked like he glued the hardi to the drywall. My goodness. Why can't these guys take pride in their work?

Pics are too big to post on the forum. Help!!

Hardiboard is not considered waterPROOF. It is designed for wet areas, like showers, but must have a vapor barrier behind it. The drywall, or bare studs, whichever it is attached to, will suffer if allowed to get damp.

Gluing to drywall probably doesn't help at all. It is the screws that hold it in place. On the floor, the mortar is to remove any possible voids due to imperfections in the subfloor. "Hollow spots" could allow deflection, movement, and tile cracking.

Shower stud walls are often less than perfect. They may not be plumb, may not all be in the same plane, and for sure are 1/8 to 1/4 back from the front surface of the tub flange. Lapping the backerboard directly over the flange is sloppy, as it causes a distinct bow out of plumb, and this will be very obvious in the first row of tiles. One techinique is to shim the studs to get a plumb surface, allowing the backerboard to be straight and plumb, and over lap straight over the tub flange, extending down to about 1/4" above the tub deck.

jimbo said:

Shower stud walls are often less than perfect. They may not be plumb, may not all be in the same plane, and for sure are 1/8 to 1/4 back from the front surface of the tub flange. Lapping the backerboard directly over the flange is sloppy, as it causes a distinct bow out of plumb, and this will be very obvious in the first row of tiles. One techinique is to shim the studs to get a plumb surface, allowing the backerboard to be straight and plumb, and over lap straight over the tub flange, extending down to about 1/4" above the tub deck.

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Yep...I went through a good deal of effort to do just this w/our remodel so the cement board behind the shower was overlapped properly. I'm glad I went to that effort though - it still looks good two years later.

to do the walls right, or to ensure that the walls get redone right, Honeysuckle, you need to answer lots of questions. Even about the type of tape used to seal the corners. I fear based on all the foregoing that you will have a problem with getting your old guy to do it right, and it will be difficult to answer all these many many questions.

send your photos to a moderator or to Terry. Somehow they know how to reduce these miraculously. It will answer a lot of questions to see the shape the walls are in and how they touch the tub.

david

This is the site with the tub in question. The one with put in.

I will take more pictures of the other side of the wall. No vapor barrier was used.

There are not enough screws in the backer board. If it is not securely screwed down, it can have flex and bow, which will lead to cracked tiles and grout joints.

I hope they were not finished and ready for tile. Each screw head needs to be mudded, and each horizontl and vertical seam needs to be taped and mudded. You use the fibreglass joint tape, and thinset or a waterproof Type 1 Mastic Mortar for the mudd.

But I would not go there at this point. You mentioned no vapor barrier, and honestly that is a major flaw. You would not see a problem this week or this month, but 10 years from now, the wall behind there could be a mess.

2 kinds of fiberglass tape. One is for drywall. One is for alkaline environments. Big difference. A shower is a harsh environment. The expensive tape, alkaline-resistant, is the right thing to use. I believe it is the only product that has been approved by the TCNA. The other tape degrades, falls apart, does not hold the seams together, in the long term. Very few people mention this, anywhere. It is not common knowledge. When you go into a store, many of the "specialist" staff won't know. Even if they read the labels, and understand it all, they may tell you that the cheap one "works too". Yes, it works, initially, as it appears to hold the Hardi panels together, and if some aisle person is all of 22 years old, his sense of time-risk-proper- and all that is not to be trusted, assuming you want the installation to be done right, by standards recognized by industry associations.


Shower water can slide in behind any tile, even thought the grout looks intact and well attached. Also, grout itself is not waterproof, unless it is epoxy based grout. A shower a day keeps the wall moist inside, if there is any small amount of water getting in. Moist = mold grows. Smells bad, makes you sick, infects the whole house sometimes.



"Mud" is a cute word. Let's call it Portland-cement based product. Thinset is one.

"Mud" is a broad term. In drywall, it can refer to "compound".

"Mud" for some people can refer to the product known as mastic, which is an organic based material, not portland cement based. Organic material rots. When put under shower tiles, it is not up to TCNA standards. Mastic is good as a tile setting product, but not in showers.


Anyone can say, that this or that thing they do is a small thing in the big picture, and that what they are doing will work, and that the TCNA has only adopted a few things as the right thing to do....

Whether you use mastic in a shower,
whether you use mastic only on the screw holes,
whether you use the right or wrong fiberglass tape,
these are details, that may make a big difference

Or none at all. But there is no way to know in advance. I have no problem with a touch of mastic on a screw hole. Just don't use mastic to set all your tiles.

Honeysuckle, these are some of the reasons why you will have a hard time with the previous guy. It takes a lot of talk, a lot of explaining, just to say all of the above. Imagine how hard it will be to talk to someone who knows more than you do and won't listen to your new-found knowledge that is still quite limited. If you have already explained all this ten or twenty time before, it gets easy. Today is not a good day to teach the old guy new stuff.


If you unscrew the Hardi, then later when you put the vapor barrier in, you have to ensure that it is long enough to "drip into" the tub flange.


You may have one other option, an alternative to unscrewing it. That is, to paint a liquid trowelable shower membrane on it.



First, we need to see how the Hardi touches the tub edge. The "flange".


david

HoneySuckle said:

Pics are too big to post on the forum. Help!!

Click to expand...

Try pixresizer; it's freeware, and easy to use:

http://www.download.com/3000-20-10607499.html

I had three independent tile setters come by, and then contact three carpet/tile stores and had them come by to quote on my kitchen floor. When they were done measuring, I asked for a quote on the same "messed" up bathroom. The consensus? They won't LAY a tile on that bathroom wall until it's fixed by you-know-who! The darn contractor I should not have hired, and he wasn't the cheapest

I called him and left a message asking him to come by and discuss how we can fix the problem. Anyone interested in taking bets? Hubby thinks he won't return my call...

Can I report him to Better Business Bureau? Should I write him a "nice" letter, talking about the problem and possible solution based on all these tile folks who inspected the install?

The BBB is a dinosaur and IMO, a lost cause. If the guy ignores you after repeated attempts pony up about $35 (that's the fee here) and take him to small claims with statements from the tile folks you've had come out.