No caulking at shower wall to pan seam?

Here is the subject; New construction home with a ceramic tile shower and a fiberglass pan.

During a recent inspection of the home it was found that no caulking had been applied at the horizontal joint located between the shower pan and the shower walls.

As typical, I recommended they had this joint caulked before the shower is used. Now their builder is not only saying that they will not caulk it, but if it were caulked, the warranty would be voided. He stated that caulking it would trap moisture behind the tile shower wall covering.

(It is ironic that this comes just a couple days after inspecting a 4 year old home with the exact same missing caulking, and with the entire sub floor rotted from the shower leaks. )

My experience is missing and/ or failed caulking in showers typically leads to water damage in some form. The absence seems to be begging for water intrusions, and movement of moisture through capillary action.

BUT, I am trying hard to keep an open mind; and my question is;
“Is there any application where it would be accpetable not to caulk this joint between the tiles and the shower pan?”

Preferably a reference to an ANSI standard, or some Tile Industry standard of practice to back it up, or refute it, would also be nice.

My intial research does not support the absence of caulking, but thought I would tap into the collective knowledge here at NACHI. Thanks.

Harold i believe your builder is just trying to snow you…i have never heard of such a warranty limitation…in fact i think the opposite is true …failure to provide a consistent bead of water resistant caulk between tile and base could void warranty of drywall and structure behind same…jmho…jim

have him produce the document where it says caulking will void the warranty, he won’t and common sense will hopefully prevail
if this is the only item stopping the transaction he did pretty good

Here’s a site that shows replacement recommending sealant as the final step.


You can ask, also, for the maufacturers instructions (and warranty info).

Here’s some…

Well that is my thought… just a way to get out of something so minor.

Nice one Barry.

Ya, I suggested that the agent have the builder show her (in writing) where the warranty would be voided if the shower wall was caulked to the pan. Obviously he will not be able to do so.

Thanks for the links. Those should be helpful.

yep, wanna bet we can find more links about repairing leaking showers than caulking voiding warranties :twisted:

He, he, he …no kidding. :smiley:

I just feel like I have entered the “Twilight Zone”, when I get feedback like this from an inspection.

I wish I knew how to upload the pictures, because it is good for a laugh. The joint is mostly bare, but with some crumbling grout in places, that slopped over during the wall finishing. At least if the builder thought that this was going to be the finished product, then they would have cleaned the crumbling grout off.

Hi Harold.
I’ve been doing tiling and showers for 24 years, here’s what I think. When you are using a fiberglass pan that has a small shallow “weep wells” to the left and right of the front of the pan… Caulk the joint in question except for the wells. That way (hopefully) any water that may find its way down the wall runs behind the tile and discharges out through the wells. If the pan doesn’t have those small notches or weep wells, it entire joint gets caulked.

Hope this helps.



Roofing caulk should NOT be used in this area!


The builder is right. The tile itself is permeable, but back behind there somewhere is a water barrier. Anything flowing down that WRB needs a way to get back over the lip of the shower pan, and down the drain.

I’m told a permeable caulk is best at the bottom edge, never a silicon caulk.

The tile is permeable, but should be sealed… So I don’t understand that statement.

really? you’re joking right? least I sure hope so

Caulking not required when the process of waterproofing the walls and shower base prior to tiling the walls.
One should have a clue as to what was used for a backer for the tile work.
Corners of the shower stalls sometimes get caulked with a matching colored caulk to allow for movement and sometimes that is not done either.
The movement and cracks in the corners of the tile grout will allow water infiltration and more reason to have a waterproof backer and no caulk at the base and tile so moisture can come out.
Whether the wall is totally waterproofed or not, the lip of the shower base is always waterproofed with a membrane before the installation of the cement board backer.
That prevents water from wicking back under the tile backer and leaking.

The photos shown on some of the links above are showing green MR Board which hasn’t been allowed for a wall tile backer in showers for years.
That is remodeling and hopefully done correct afterwards.

Here is a pic of a waterproof shower.