Gah, I hate having to stress over these details but I do want this done right!

Also I noticed that the grout seems to suck up water and stay wet looking for a while, when it gets wet (they've been installing faucets so some dribbles of water are around). My contractor said that's because they haven't sealed the grout yet. Is this true?

Having said that, areas such as this and, generally, ANY "Change of Plane" should be filled with caulk. Color-matching, sanded silicone caulk is King. A little tougher to find, but it's out there.

Needless to say, caulking should be done around any areas where the tub lip or edges meet the wall or wall tile, as well.

Last, I remember someone stating that when you caulk your tub have it filled with H2O, (then I suppose to let it dry while tub is filled). I only guess that is so that it is applied when the tub is under the most stress.

Regardless, it boils down to, your contractor works for you. It is your bathroom and whatever his opinion, he should have understood the risk of what he was doing and left the final decision in your hands. I personally would make him grind out the grout and apply caulk so you don't have to deal with it later on.

*****
When do you use caulk instead of grout?

Technically, anywhere there is a change in substrate or backing surface such as the joint between walks and floor and wall joint, caulk should be used in place of grout since these surfaces move independently of each other. However, it is important to recognize and make the end user aware of some important points.

Often, installers use grout in place of caulk for these reasons:

The caulk may not exactly match the grout color.
Even when the caulk exactly matches the grout color when installed, it may not match six months later (caulk will "age" differently from the grout).
Caulk will need to be maintained more often than grout.
Mold may grow more easily on caulk (except caulk treated with mildewcide) than on grout.
Acrylic caulks break down in horizontal wet applications. Silicone, urethane, or multi-polymer caulks are better choices but can be harder to apply.
However, when grout is used in place of caulk, the grout can cause structural and aesthetic problems.

The grout will crack allowing moisture to penetrate.
Where the grout is sufficiently strong, movement in the walls, floor, or countertop can damage the tile.
Grout cannot hide corner cuts as well as caulk.
In summary, caulk is the better choice, but the customer needs to understand its limitations.

******

Basically, the CUSTOMER should be informed and make the decision themselves. It was not the contractors decision to make, there are drawback to each method and as with any and ALL methods everyone has an opinion (I am a caulk fan all the way so no really arguing with you there), but it is never the contractors final decision to make as it is not their house and they are not paying for the job, they are being paid to do a job.

The joists do not have zero deflection at these size of loads.

That means the tub moves down ever so slightly.

It WILL crack a grout joint.

Use caulk.

I do not use silicon caulk since it is all but mposaable to get your fingers clean enough to not ruin contact lenses.

The 'siliconized' caulks are much better.

I have had bad luck with GE silicone white not staying white for long.
My wife than demands it be replaced since she cannot get it clean.

Perimeter and field movement joints are essential and REQUIRED.

Snip

PERIMETER JOINTS: Movement joints are REQUIRED Where tilework abutts restraining surfaces such as perimeter walls, dissimilar floors, curbs, columns, pipes, ceilings, and where changes occur in backing materials, but not at drain strainers.

You can bet if there's ever any question about any given project, THIS is where they'll go for reference-- not to the FAQ's.

However, when grout is used in place of caulk, the grout can cause structural and aesthetic problems.

The grout will crack allowing moisture to penetrate.
Where the grout is sufficiently strong, movement in the walls, floor, or countertop can damage the tile.
Grout cannot hide corner cuts as well as caulk.
In summary, caulk is the better choice, but the customer needs to understand its limitations

You were wrong even by your own link!! I KNEW I should've checked before I posted from my own reference. I couldn't believe that the TCNA would contradict itself like that!

It might look 'better' long enough for you to sign the final cheque, then it will crack and be gappy.

Hopefully, the bath won't be damaged when they scrape the grout out.

That being said, especially if you use silicone caulk, you could probably do a thin skin over the grout, but it'd be better if it was scraped out.

I have clearly stated several times that I am on the side of caulk. I have also stated that the contractor is WRONG and she should have them come back and take the grout our and replace with caulk.

HOWEVER---- I believe the point of my argument is that the topic is obviously decisive. This was HER decision to make, NOT her contractors, however, there is OBVIOUSLY room for debate or there wouldn't be so many threads on this forum about it NOR would the TCNA even suggest it is an option.

She should at least be given the information that it is an option and is not as outright wrong as everyone keeps telling her it is.

My brother in law was trying to convince us to use grout instead of caulk because he built our structure and insisted it wasn't moving. I for one didn't believe anyone could build anything to guarantee it wouldn't move or shift even so slightly to assure that the tiniest bit of grout wouldn't crack, but he being a contractor (and I will admit although he is full of it most of the the time he does do very, very good work) for 40 years, kept insisting.. hence the argument. When you do a search of the internet there are many touting the benefits of grout over caulk with the same veracity you are fighting it.

I am honestly trying to give her information. I fear that like my brother in law, who remained very angry about us not listening about the grout vs caulk (and the glue for drywall but that is another story) some contractors who have been doing this a long time one way have a very hard time believing there could possibly be another "right" way to do things. I am not a contractor, I am simply an avid DIYer who does a LOT of research before undertaking a project.

For lightweight tile backer board over wood frame construction, especially in new construction where the wood might still be acclimating, caulk will handle any movement much better than grout.

Yes, I'm upset that it wasn't my choice, however there are certain conversations I took for granted that I wouldn't have to have, this being one of them. Kali, you've mentioned that it was my decision to make but really, how much do you have to anticipate that you will need to micromanage the job? I've had tons of detailed conversations about the positioning of this that and the other, more aesthetic kinds of decisions. I've micromanaged a lot of this project and there are just certain things your tradespeople should know without the necessity of having a conversation - lesson learned on grout v caulk!

I think this is the way he's done things and he remodels bathrooms constantly and of course I wish it was a conversation we would have had before the grout went in and I had the benefit of this thread.

Thanks for all the time and input. I would probably not hire this guy again. I think overall, we've got a great looking bathroom, but I just need to have more confidence that I can leave the details to the pros.

Kali-- My apologies. I read thru it too quick. It still should not be done, and TCNA is NOT advocating the use of grout under ANY circumstance at changes of plane, What they're saying is that there are installers who will do this, and it's wrong, and this is why.

Kali-- My apologies. I read thru it too quick. It still should not be done, and TCNA is NOT advocating the use of grout under ANY circumstance at changes of plane, What they're saying is that there are installers who will do this, and it's wrong, and this is why.