bath tub mold grout or chalk?

[sharon hassinger]

Hi,

This forum is great! My company provides mainteance for a four diamond hotel and we have been struggling to find a solution to mold problems in the the bath tub area.

In particular the joint line between the white porcelin tile and the enamel bath tubs. Right now we have chalk in the joint and are considering replaceing it with grout.

Here are my questions,
1) Will the grout make it easier to prevent mold?
2) If the grout is sealed will that prevent mold.
3) If we choose to remain with chalk, can that be sealed to prevent mold?
4) Once mold has started to grow, what is the best solution to cleaning it?

I look forward to your response.

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[kkowal]

there is a number of possibilities here. firstly, finding the source of the mold problem. mold can occur when showers and tubsurrounds are improperly installed with inferior products. for example, using drywall in wet areas is incorrect as moisture gets behind regardless of grouting and caulking and eventually you end up with mold coming to the surface. we've yet to find any product to get rid of the mold. basically you rip out the installation, use bleach to kill the mold and reinstall. obviously this is not the solution for you but neither is caulking or grouting the problem areas. mold, if not tackled directly, will resurface. any cleaning products currently available are a short term cure and can be abrahsive. others here may have different experiences with mold and how to cure the problem. our experience was with customers not knowing how to properly install showers and tubsurrounds with the right products. it is unfortunate because mold can come up pretty fast and it is a health hazard.

[John Bridge]

Hi Sharon, Welcome to the club. :D

The big problem in that area is that aren't given enough time to let the joint dry out before you re-caulk it, so you are sealing moisture in with the new caluking. There isn't a good answer to your problem.

Grout won't stay in the joint. That's why you find the caulking there to begin with. If you can figure out some way to remove the old caulking (along with the mold/mildew), allow the joint to thoroughly dry out (or dry it out with blowers or something) and then re-caulk, you'll be ahead of the game -- for a while. ;)

[KChurch1]

All the above advice is good. There is no remedy for moldy caulking.... when it molds/mildews, it needs to be replaced. You can't clean it off. I think Dap has a mildew proof caulking. I've used it once, that was about a year ago. I probably should check with the client to see if the mildew has returned. I recall reading on the Dap caulking container that it's not suitable in areas that were previously caulked with a silicone caulking.
When replacing caulking, it's imperative that the area be allowed to dry before recaulking and that the caulk be given time to cure... this can be anywhere from two hours to 5 days... depending on the brand/type of caulking. If these rules are not followed, you will be replacing moldy caulking more often.

[flatfloor]

After you remove the caulking from one or two rooms maybe the hotel can leave them idle for a day or two then try this formula.

http://johnbridge.com/vbulletin/showthread.php?s=&threadid=4991&highlight=mold+formula

[Unregistered]

Our (different) problem is that our genius installers ran clear silicon over the the corner grout lines, and of course, the mildew/mold is starting. I know I should remove all of the silicon and grout, let dry, and then caulk only, but what is the best way to completely remove the clear silicon?

[KChurch1]

Solvents, like acetone, help, but normally we use a razor blade or grout rout to scrape away the caulking and use the solvent to clean up the residue.

[Unregistered]

Thanks, Karen!

[Roger3125]

Thanks everyone from saving me a whole morning of taking pictures, figuring out how to upload the pictures to the site (which incidently I still don't) and describing my shower problems. As it turned out what I am experiencing was described to the tee in the above posts.

Any one else have a stall shower 40 years old with ceramic tile walls. Is it really true that ceramic tiles are not moisure proof? I'm amazed as recently we had another bath that shares the same wall with my bath remolded and the studs in the wall were bone dry. 40 years,,,,that be good, isn't it?

Roger :yipee:

[Roger3125]

Sorry, I forgot to mention in my previous post...anyone have some thoughts of the good and the bad about installing ceiling exhaust fans in small batrooms. The two bathsI have been describing are both about 7 by 8 ft. Moisture in the room as indicated on mirror and of course, the mildew problem. Was thinking of installing a ceiling exhaust in one or both.

Any thoughts on the kind to use and place of such. Directly above the shower, off to the side, above the mirror, etc. Thanks again

I'll be quiet now

[John Bridge]

Hi Roger,

Exhaust fans are great. Get one that's over 200 cfm, though. The little builder's models don't move any air; they just make noise. Mount it near the center of the ceiling outside the shower. How you are able to route the duct will determine fan position, I imagine. :)

[Roger3125]

thanks John for the heads up about exhaust fan in the bath. Always wondered if it should go above the shower or be offcenter. Always thought if above the shower it would collect too much moisture and rust. Regardless if that be the reason or not off center it shall be.

Can I exhaust it into the attic or better to go through eve to outside? Why do I feel your going to say outside and make it that much more difficult for me? Also if I have two adjacent baths can both be Y'd into one another? Pls forgeive my technical terminology.

Is it more common to have a dedicated electric switch for the fan or have it joined into the light switch?

Thanks good buddy
Roger

[doitright]

Hi Roger :)

Exhaust vents should always vent outside. Otherwise, you're just dumping extra humidity in your attic (not recommended).

Seperate exhaust venting is always best (unless you're using a central exhaust fan). Depending on your units, the run length, and whether or not you have backdraft flappers in the existing fans, you may be able to join the existing ductwork with a y.

While joining the fan with the light switch is common (as it ensures the use of the fan), it's not my favorite. Personally I favor independent switches. :)

[Unregistered]

I agree with what jon said drying the shower out is the most important part and also when you recaulk the shower make sure you use 100% silicon we use which is called latiseal. If you use 50% latex 50% silicon caulking it will within 1 year do the same thing as we all know what water does to latex therefore 100% silicon caulking is a must.

[Jim Cuviello]

I did not see it mentioned but it appears that there is no natural stone in the area. If this is the case great but if there is a natural stone surround or floor becarefull what cleaners you use around the stone. We have used MB Stone's Mildew Stain Remover in the past that will not damage the stone.

[Unregistered]

I agree with what jon said drying the shower out is the most important part and also when you recaulk the shower make sure you use 100% silicon we use which is called latiseal. If you use 50% latex 50% silicon caulking it will within 1 year do the same thing as we all know what water does to latex therefore 100% silicon caulking is a must.

I have a friend who is a retired plumber, Many years ago he recommended a product to me called "Polyseamseal" He said that is all he ever uses on shower & tub installations, I used it 5 or 6 years ago to seal a crack in a toilet water tank and it has never leaked! the big secret ( like everyone has stated ) is to make sure every crack and crevice is thoroughly dry! This product can be purchased at almost any hardware store or plumbing shop, or Lowes & Home Depot

[doitright]

D/2 Architectural Biocide works great also on mildew, and safe for all surfaces. We also use it extensively on exterior areas of stone that have the green algae and moss (on the shady side of buildings).

Polyseamseal is an excellent caulk, available in several colors (including clear). As with any caulk, it must dry thoroughly, before moisture can be introduced. :)