Voice your concerns with the contractor.

All wrong for either and get this done right now or live to regret it.Tile backer does not mean good for showers get the waterproofing done right .

You want some sort of cement board. The drywall you're referring to is appropriate for the walls in a bathroom, but not the walls in a shower/tub. Obviously your contractor thinks it's acceptable, but it is not preferable, and an experienced tile setter wouldn't have chosen it.

e-XP Tile Backer "appears" to be rated for use as a tile backer in wet areas and is waterproof. I have no idea how you will what he used from a picture. Is there any scrap pieces laying around? Does he have a receipt showing what was delivered to your home?

It's water resistant drywall which is not for shower area with direct exposure to water. I plan to apply grout sealer by myself. Do you know approximately how many years this shower can last if it's only used a few months per year? It's inside the guest room. The tiles are already installed. I'm not sure if I should ask the contractor to tear everything apart and redo it. Thank you.

No guarantees, but grout sealer is not waterproof and will do nothing to stop the water. You may start getting mold in a few years or it might be longer. It will happen and the more it is used the worse the mildew and eventual rot. Up to you how you proceed

Sealer isn’t waterproofing and none of that meets code. No gypsum based anything in a wet area. That’s a mold sandwich getting ready to be created. You look at that and have to ask what else is jacked up and going to be a problem after his tail lights fade in the distance.

Tile sealer seals the tile does not seal out water you need to start over and if you don't you will be back here very quickly wanting to know who you can blame when the wter is leaking.

Sealer does nothing. If a shower is properly waterproofed you could shower in it before you lay the first tile.

"Have the contractor apply Schluter Kerdi membrane over the gypsum board and the walls will be completely waterproof, gypsum board or not."

HU-867564120, OP stated tile is already installed.

"Gypsum anything doesnt belong in a wet area. Period. Junk products. And that is going to have moisture issues."

This is old-school money and time wasting thinking. Yes, years ago inappropriate gypsum products were used in showers and failed. This ain't that. This is state-of-the-art technology verified by 3rd parties. Get with the program, Luddite.

Properly installed, this installation will not have moisture issues.

This ain't that.

@Joseph Corlett, LLC The contractor confirmed that they used "Gold Bond XP drywall sheet" as tile backer. The product description says "Use as a tile backerboard in dry areas, and in areas with limited water exposure" The contractor didn't apply any waterproof membrane like REDGARD or Schluter Kerdi. They only taped the drywall joints and then apply thinset and tiles. Do you think this will work fine?

Do you know what is the best way to protect the bathtub when removing the tiles and the backer board? The contractor damaged the bathtub (more than 30 chips and dents) last time so they had to tear down the wall and replace the bathtub.

No. it won't work fine.

If the tile backer plainly says, "not for use in wet area", then what are you asking about?

No. don't use it. don't apply Redgard to it.

As for Schluter or Kerdi, check w/them to see if it's a suitable substrate.

Why didn't they just put up Durock and use Redgard over it?? tape, mud the joints, redgard, done. This is only partially done. all of it should be painted.

UNLESS, you choose to do a vapor barrier BEHIND the cement board

In this case, no waterproof membrane on top of the board is required.

Again, remove the purple stuff and use the products that are meant for wet areas.

And let me stress again, Grout Sealer does not make grout waterproof.

Did they already tile this bathtub surround??? good lord. if they did, it's not correct and you're setting yourself up for failure in the future

@Beth H. : From the OP:

"The tiles are already installed. I'm not sure if I should ask the contractor to tear everything apart and redo it."

"they used "Gold Bond XP drywall sheet" as tile backer."

"The contractor didn't apply any waterproof membrane"

"They only taped the drywall joints and then apply thinset and tiles."

You will need to completely tear out the tile and wall board, and it seems you now understand that.

"Do you know what is the best way to protect the bathtub when removing the tiles and the backer board?"

Before doing that, cut a sheet of plywood to fit and rest on the lip of the entire tub.

Lol, the contractor has even replaced the tub once before, so she'll see if a lesson was learned in that regard. However, I don't think she will be able to teach this particular contractor how to install a surround correctly and with the proper materials.

"Do you think this will work fine?"

It depends upon how often the shower gets used. Six times a year for a guest and you'll be fine. If you'll use it daily, I'm going to have to join the tear-it-out club here.

Fire the guy you hired and get a person who knows how to do the job correctly.

I'm building this new house with a nationwide production builder. Their construction team insists that nothing is wrong with the purple drywall they used in the bathroom. I checked the Residential Code of my state and it's clear that "Water-resistant gypsum backing board shall not be used where there will be direct exposure to water, or in areas subject to continuous high humidity."

The builder refused to fix this issue and they asked me to close the house next week. I'm still awaiting the feedback from the city inspector after talking to him last week. Could you give me some advices? Thank you.

There has been a ton of advice. If they refuse to remedy the shower, and the building dept. issues the CO, you have 2 options close or lose your deposit and they will sell the house for more dollars to someone else. ot much else you can do , a tract builder does not care enough to make this right, it will cost him to much and mess the overall schedule of the development to do anything else.

My advice: Close on the house next week and monitor the shower to see if it becomes a problem.

In a production build you are buying a completed house that has been built by someone else. Legally, it is pretty similar to buying an existing home and is not like building a home on property that you own. You really have no leverage to demand a change and this is not worth losing your deposit or paying late fees over.

What they have installed is a system that has a much higher likelihood of being a problem, but it is not necessarily going to be a problem. I tore out a shower in a property that just had tile over regular drywall without any product to retard water and it was pristine after 30 years and that was a three bedroom, one bath home.

Grout sealer is waterproof, I am not sure why people are saying it does nothing. The entire purpose of the product is to is to put a molecular layer smaller than water molecules on a surface so that water molecules can't enter the grout. That is the exact same way that all waterproofing happens. That doesn't mean than anything you paint on tile grout is going to turn your shower wall into a submarine, but it will retard water while it is intact. Since it is your only safety layer, you will need to be diligent about cleaning the walls and reapplying sealer, but it can extend the life significantly and, under the correct conditions, permanently.

I'm guessing this isn't the only place the builder cut corners.

"I'm building this new house with a nationwide production builder."

Yikes. Maybe you can be part of a future class action, like chinese drywall.

"It's inside the guest room."

I'm sure you have more than 1 bathroom. Have you thought about the other tubs/showers?

The tile backer in another shower is the Denshield which has an additional water barrier on it.

The builder redid the bathroom shown on the picture because the contractor damaged the bathtub. The builder told me that the Denshield was out of stock so they used the purple drywall as a replacement.

The builder won't allow me to access the house during the process. I found out there's no water barrier on the purple drywall but it's too late. They have installed all tiles.

I found this sentence on the agreement- Moisture Sheetrock installed in wet areas per code

The XP purple drywall they used surrounding the bathtub is not per code.

Do you think they can hold my deposit in this case?

I think you should prob get some legal counsel. can't believe the builder won't budge on this even after showing them the specs on the purple stuff that comes directly from the manufacturer! it clearly states "not to used in wet areas". In the first paragraph of the page you posted, it says the gypsum board has to adhere to ASTM C codes. (And the ANSI codes which tells you how the ceramic tile is to be installed on these products) I would look up each of those codes and see what it says. I bet it's going to say you have to use something like Kerdi or Schluter membrane over it.

https://www.astm.org/c1396_c1396m-14.html

https://blog.ansi.org/ansi-a108-a118-a136-2021-installation-ceramic-tile/#gref

2509.3 Limitations

Water-resistant gypsum backing board shall not be used in the following locations:

1. Over a vapor retarder in shower or bathtub compartments.
2. Where there will be direct exposure to water or in areas subject to continuous high humidity.
3. On ceilings where frame spacing exceeds 12 inches (305 mm) o.c. for 1/2-inch thick (12.7 mm) water-resistant gypsum backing board and more than 16 inches (406 mm) o.c. for 5/8-inch thick (15.9 mm) water-resistant gypsum backing board.

If you have those codes saying it's not right, and you have the purple stuff people saying it's not right, and the builder is still refusing to fix it, then I'd say you have a pretty case if you want to go that route.

But like mentioned above, if he skimped on this one thing, how many other things did he cut corners on? We've all seen the shows, and we've all read horror stories on here w/builders of these homes. (there was one who fought for two years to get 50 diff things fixed in her home! And I'm not exaggerating) The builder waited until the warranty expired and then kept blowing her off saying, "it's no longer covered". I have a feeling you'll run into the same issues w/this crook.

if you want the house, present him w/the evidence. if he refuses, bargain to get your deposit back and you'll drop it. If he refuses, then I guess you have a choice to make. Speak to a lawyer first to see where you stand.

Or, just eat the 10K and redo the shower when you move in and pray that other water related issues don't pop up down the road.

Unfortunately, most large production builders have clauses that require closing the house once the CO is issued or face significant penalties, which can eat through a deposit pretty fast.

The problem is, even if you have a winnable issue, you still have to close, but once you close the chance of winning the issue goes down significantly. So it is often very difficult to negotiate repairs and deposit returns at the end of the build.

I wouldn't close on this house unless they fix the issue, or put in writing that they will fix the issue by a specific date (which is less preferred and risky). You have much less negotiating power once you close on the house. Even if they threaten to fine you for delayed closing, I would assert that it is not done to code or to their contract. If you really want your deposit back, I bet that you can negotiate to get a full refund of your deposit in order to just let this whole thing go.  You still have some power as long as you don't close on the house. Even if they think they could turn around and sell it for more, they would still need to find a buyer with financing lined up, schedule closing, etc. That all still cost them more money.  Plus there is a risk that you could sue them.  I would escalate the issue and ask to speak to someone higher up if the person you're speaking to doesn't have the authority to get this resolved.

I would recommend a consultation with an attorney before any more communication with the builder on this issue. Take your contract along with you and do it before delaying the closing.

Many of the large production builders are a bit ruthless about closings. Essentially you have agreed to buy a house from a seller when certain conditions are met. You can't go back now and add conditions into that agreement that were not there to begin with. Even when those conditions seem as obvious as code compliance.

Most of these contracts contain a clause that the buyer can't delay closing once the certificate of occupancy is issued, even if there are legitimate issues. The OP has likely already agreed to close on the home and then continue to negotiate or litigate issues. Production builders do this to remove the problems that were discussed above.

Additionally, saying things like "I am not going to close unless," can trigger a breach. They can then go sell your house to someone else, keep your deposit and possibly sue you for any discounts they had to give.

These things seem unreasonable but some of these large national builders have a history of dubious business practices. Not that long ago there was a class action because a national builder would schedule several closings on Thanksgiving and Christmas eve, and then charge the delay fees for their office holidays if you couldn't close the home on those days.

Take your evidence to the local building inspector please. The builder won't get a CO or may have an issued CO revoked. If that's happens, he won't be able to tear that out quickly enough.