Hairline Gaps, Pink Mold, and Sealer Question

[JamesRGeib]

I have a fairly new home (about a year old), and the master shower was tiled. Between the floor tiles and wall tiles a few hairline gaps have formed (1/16 of an inch or so and about 8 to 10 inches long) due to settling. The shower was lined with a paint-on liner before the tile was put down, there is a proper mud bed on the floor, and cement board was used for backerboard. The shower has also been sealed by me. It doesn't seem that water has anywhere to go even if it got in these small gaps, but could this be a problem I need to deal with? I don't want to have to repoint the grout. Is there a good sealer that can simply fill in these gaps?

The small amount of water that gets in the cracks takes longer to evaporate too, so we are getting a small amount of pink mold near them. We do dry the shower completely after each use. Any good ideas on removing the pink mold?

Thanks for any help/opinions on this!

James

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[Tool Guy - Kg]

Welcome to the forum, James.

The "change of planes" between the walls and the floor needs to be caulked with a flexible sealant, not grout. The walls and floor expand and contract independantly of each other and need the flexibility afforded to them by a flexible material. Dig out the stiff grout the best you can and caulk all the corner joints in the shower.

100% silicone sealant is very flexible and that's what I would use if shiny caulk wasn't a problem. Otherwise the next best thing are the color-matched caulks that have a matte finish to them. :)

[JamesRGeib]

Tool Guy,

Thanks for the quick reply. That does make sense, but poses another question. I used a polymer sealer on the grout. The polymer sealer doesn't play well with caulk! If I take out the grout and use a color-matched caulk, how do I re-seal the shower? Are most sealers compatible with caulk, or do I recaulk when I reseal? One other question on the same topic: Can I reseal with a different type of sealer over the polymer sealer?

James

[Tool Guy - Kg]

It isn't an issue. You are only digging out the grout in the corners and replacing it with just caulk. Silicone doesn't need to be sealed. It is far more effective against moisture than any sealer is.

And since the only grout you are disturbing is being replaced with caulk, you don't need to re-seal anything. :)

[JamesRGeib]

When I go to reseal the shower in a year or so do you think there will be an issue with the caulk and polymer sealer?

[Tool Guy - Kg]

No. Periodic re-sealing of a shower with caulked corners is the norm.

But I don't understand what you think will happen. Please explain your concerns. :)

[JamesRGeib]

Thanks for your patience! I used a Homax 10 year polymer sealer on the grout, and I'm worried it may not be compatible with other types of sealers being applied directly over it. I really don't trust it to last 10 years, so I would like to reseal the grout at some point with another type of sealer.

[Tool Guy - Kg]

You are right in being concerned that other sealers may not be compatible with the Homax sealer. I can't say I'm familiar with that sealer.

Remember, this caulk job I'm suggesting is purely in the corners where walls meet other walls, or where walls meet the floor.

If you like, we can move this thread over to the "Cleaning, Sealing, and Restoration Forum" if you have specific questions about your sealer. If you do, give us a holler and we'll move it for you. :)

[JamesRGeib]

Sure, we can move it. It's more appropriate for the mold question anyway!

James

[Tool Guy - Kg]

Oh, yeah, the mold. Take a look here in our Liberry (http://www.johnbridge.com/vbulletin/forumdisplay.php?s=&f=8&page=1&pp=60&sort=title&order=asc). It's filled with solid info about all sorts of tiling topics. There are a couple of threads that will interest you. The "About Mold" thread, and another with the title of "Mold Removal Formula".

Little tip: The more specific you can get with your sealer (or cleaning) questions, the better they'll be able to help you in the cleaning, restoration, and sealing forum. I'll move you over now. :)

[JamesRGeib]

I've used it on my shower, and wonder about compatibility with other sealers in the future when I reseal my shower. Any ideas if I'll run into problems?

Thanks,
James

[tileman2000]

Hi James,
Which Homax sealer did you use?I believe that's a water based sealer and you should have no problems re-sealing.And it's a decent sealer from what i can tell.

[JamesRGeib]

I ended up using the 10 year polymer sealer. I haven't been able to find any info on resealing over it.

[sandbagger]

while the caulks are pretty neutral to the sealers, you don't want to leave solvent-based sealers on the caulk for more than a few minutes. Extended exposure can weaken the caulk, as someone found in another thread.

I suspect the pink stuff will go away when you caulk. Just curious - is there by any chance a skylight near the shower?

[JamesRGeib]

sandbagger,

No skylight near the shower. I always thought it would be a good idea to have a UV light in a shower that would automatically cut on for a few hours to help kill mold. I never did do any research on the validity of my assumption.

James