I remodeled a bathroom about 6 years ago and the homeowner recently called me and said the caulk needed to be redone. When I got there, I could see why. He is a 65 year old bachelor and the tub had not been cleaned since I installed it and mold was growing on the caulk.
After thoroughly cleaning the tub and tile, I removed the old caulk and recaulked using tub and tile caulk. (I can’t think of the brand, but it was the only tub and tile I saw at Lowe’s.) About two weeks later, he called me back and said the new caulk was failing. When I arrived, the caulk on one portion of the tub looked like it had melted and was similar in consistancy to caulk that is not fully cured. I questioned him about exposure to any chemicals and he said there was none. The only things the caulk was exposed to was water, Tone soap, and Head n’ Shoulders shampoo.
I couldn’t figure out what caused the caulk to fail but went ahead and cleaned the new caulk out and cleaned the area good with alcohol to try to remove anything that might be destructive to the caulk I would be putting in. Although he had half a tube left from where I had previously caulked it, I went to Lowe’s and bought another tube in case the earlier tube was defective in some way. It was the same brand as what I had used two weeks prviously.
Two more weeks went by and, Tuesday, he called again. I went over and it was the same thing. The caulk looked as though it had melted. I am at wits end as to what is causing this. He wondered if the hot water in his shower was causing it but his water heater is set VERY low. The first time, he used his other bathroom for 24 hours after caulking before showering. This last time, he waited 3 days before showering so the caulk had plenty of time to set up good.
I’m going back on Monday and clean and caulk it again. I have already bought a different brand (Dap) of tub and tile to try on the chance that it is defective caulk. Does anyone out there have any idea what may be causing this? I have never seen anything like it. I’m almost to the point of having him have his water tested to see if there is anything in it that shouldn’t be there. Any help will be greatly appreciated.
Elections belong to the people. It is their decision. If they decide to turn their back on the fire and burn their behinds, then they will just have to sit on their blisters. ~ Abraham Lincoln
Replies
Mckenzie
I have had the same think happen and was going to put the question out there myself, with a second part but you got to it first,
I my case it is a tub with shower, a soap dish is in the center right below the soap dish the caulk has a gummy melted look. Recaulked it and the same thing happened, but not as fast as in your case. It took several months, my thought is the soap or type of soap has some type of reaction with the caulk. I used Dap caulk with mircoban the anti mold additive.
The other problem I am having is the caulk seems to get black mold not on it but ratter in it under the surface of the caulk. I think it is the mircoban additive that is the cause of the problem in my case, Did yours have mircoban in it?
Wallyo
Sounds as if moisture is getting behind the caulk or the wall. Re-grouting and sealing would be my first fix. If the mold persists, make a hole in the other side of the wall and take a look. Most silicone caulks need to cure 24 hours to cure before seeing water. Good luck,
Jim
The awful thing is that beauty is mysterious as well as terrible. God and the devil are fighting there, and the battlefield is the heart of man.- Fyodor Dostoyevski
Moisture behind the wall?Yes it could be happening but I have had the black mold happen on several baths. The last one was retiled just 2 years ago, it happened on all three walls the caulk looked like it had been there for ten years. I did the tile job no chance of a leak. Also it was in a rental and the tub had about three weeks to cure since the apt was empty and no one used the shower in that time. Yes moisture behind a wall is always a problem but to have this problem on more then one bath?The other bath with the melting caulk I also tiled. It is older but the area is always the same right below the soap dish. Now that I think about it I tHink I have recaulked it 2 times. Every time I have used dap with mircoban latex/siliconized caulk. All of the tile jobs are on durock or hardie board with thinset mortar.I think I am going to switch brands and try 100 % silicone caulk.Wallyo
It's my understanding that mold needs 2 things to grow (the spores are everywhere), food(wood, drywall mud, mastic, paper faces of drywall, skin cells that we're always shedding, etc.) and moisture. So in my mind, the job is to figure out if; a) the folks shower often(shower never dries), seldom clean, don't use an exhaust fan properly, and or there are areas that hold water. b) Accept the fact that grout, mortar, and cement board are not water proof and consider that the construct may be deficient.I had a similar problem with mold under a large soap dish. It turned out that the 2x block I screwed through the durarock to support the dish while the thinset cured would get wet and mold. I ended up redoing a large section of the wall 2+ days work, all on me. I reset the same soap dish and used a 2x wrapped with visiqueen, ran the screws out before re-tiling I`heard the block fall), and filled the holes with 50 year Polyseamseal. After that wake-up call, I did a lot of research on building better wet areas. Now our showers get either Kerdi or Latticrete 9235. 20+ showers and 3 years later, zero callbacks. just my $0.02Jim
The awful thing is that beauty is mysterious as well as terrible. God and the devil are fighting there, and the battlefield is the heart of man.- Fyodor Dostoyevski
From what I remember, 100% silicone will cure even under water! I installed a special seat where my toilet flapper sits (the old one kept leaking, no matter what I did or what kind of flapper I used, so I bought an over-sized flange-like seat out of a catalog) and the instructions said to glue the seat in with silicone and you could use the toilet right way because the silicone would cure under water. Seemed to be true.
100% silly cone is not the way to go....
use one of the poly types other than Dap...
try Stika...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
By poly I take it to be poly urethane? I never seen a caulk labeled poly just silicone, or latex siliconized. that is both the box stores and my tile supplier where does one find it I would remember $11.oo per tube.What does it clean up with I just used a urethane grout that can be used as the caulk, loved it. Put the grout in a piston cake decorator from the dollar store it came with a tip that gave the perfect bevel, cleaned wet with water when dry you used a concentrate they included.
Lowes for the poly...
and it's 3 bucks and change... or so a tube...
HD for the 5600.....
and a caulking supplier for bothe of them and more...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
Yes, mine had Microban. I still can't remember the brand though.Elections belong to the people. It is their decision. If they decide to turn their back on the fire and burn their behinds, then they will just have to sit on their blisters. ~ Abraham Lincoln
One possibility is that the caulk never fully cured due to moisture. Could there have been residual moisture in the seam? For example, the tile backer got wet and hadn't dried out yet? Silicone caulk would cure better if that's the case, but I prefer tub & tile caulk because I haven't found silicone to adhere as well to porcelain.
I don't think this is the likely explanation since the caulk would only fail in those areas where moisture was persistently present, but it's something to consider.
Seems to me that there is moisture getting to the caulk from behind. Wicking from the green-board which may have been used This happened to me caulking a lead shower pan that had failed. Under the tile it was filled with water. Learned this on my second visit. Shower stall had to be redone.
You got some bad caulk. It was old or had been allowed to freeze.
I think DonCanDo has it. Probably moisture behind the joint. Clean, scrape with a razor to remove all old caulk residue. Then use a ScotchBrite green pad with alcohol or other solvent. Then put a fan on it for a few hours. Slide in a paper towel when you think it's dry enough. It will tell you if there is any more water in the joint. A blow dryer or heat gun may do the trick too.
I like to use 100% silicone kitchen & bath caulk, one with a mold inhibitor.
If the joint is big, use backer rod.
Then give it 24 hrs. minimum to cure.
Pete Duffy, Handyman
I agree with DanH. Check the expiration date on the caulk. I had the same result with some that had gotten old.
I vote for the area you caulked not being completely dry.
I've taken a heat gun and used it to try to dry out the area you're caulking before. If the substrate is saturated, it may take months to dry out if you're not lucky.
Jon Blakemore
RappahannockINC.com Fredericksburg, VA
when the substrate is damp us a mositure cure poly caulk....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
I wasn't aware they existed. What brands do you like?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Vulcum...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
can't remeber the other one...
got a brain lock on it...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
PL also make poly caulk..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
YUP...
that's the other other one...
and OSI...
if one of those 4 don't do it... nothing will...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
Don't forget the 3M 5200 polyurethane caulk. $11 a tube and fantastic adhesion. The tubes are aluminum to keep the contents from absorbing moisture through the walls of the tube. Available at boating stores and at HD out here.Bill
the BB's carry that now...
for less$$$$$
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
Yep, PL poly is great caulk. If you've used it you know it is very sticky so you have to take extra care when applying it. Mask the joints with blue tape first.
Today, for the first time, I used denatured alcohol to tool the joint (with double latex gloves). That's the way to go -- it worked much better than using mineral spirits to tool poly.
Billy
...doing a little work on Mother's Day...
BillHartmann is 100% correct about neutral cure silicone. I have used a lot of it and yes, it doesn't smell of acetic acid, kind of a 'pleasant' smell, actually. I rarely see it at the box stores or lumberyard, usually find it at the sealant/glazing supply houses.
I have only use PL Poly on exterior work.Never thought about using the alcholo.I use rubbing alcholo for tooling, pre cleaning, and cleanup on silicon..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I've used it only on exterior work too. Today I was caulking some wooden window frames in window wells. Maybe I'll try the PL poly in a bath someday.
I'll try the rubbing alcohol the next time I use silicone - thanks for the tip. The rubbing alcohol probably will work on the PL poly instead of denatured alcohol.
Billy
Sitka was the other one...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
Occasionally I get a tube of silicone which has gone bad. Fortunately it's easy to tell before applying it. If the amonia smell is not there, or very weak, don't use it. I learned this the hard way when I unknowingly used some bad silicone caulk in two different showers for two different customers. I noticed it didn't smell as bad as what I was normally used to, but thought nothing of it. The both called me back within a few days and I had to scrape out the uncured caulk, then clean up the residue with paint thinner, before applying new caulk. Of course, I took a sniff of the new caulk before applying it, made sure it stank really good.
On another note, this actually worked in my favor. One of the customers was planning on having a small deck built and didn't know I did carpentry work. She was discussing it on the phone with another contractor and I overheard the conversation. Asked her about it, she asked when I could start, and I said tomorrow. She's still a regular customer to this day.
Anyway, if you use silicone, always give it the sniff test first. If it doesn't burn your nostrils, don't use it.
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Cheap Tools at MyToolbox.net
See some of my work at AWorkOfWood.com
"Fortunately it's easy to tell before applying it. If the amonia
smell is not there, or very weak, don't use it."First it is vinegar and not amonia smell. Actually acetic acid.Also there is what is called Neutral Cure RTV.It has been around for a long time. Used for use on electronics.But, for some reason, it is now becoming common in general
purpose caulk.The GE type II RTV silicon is a neutral cure." Our very best Silicone Sealant. A premium neutral-cure RTV Silicone."http://www.gesil.com/product.asp?pid=GE5030-12C&srch=202&key=CATID&catalog=&brand=&saleprice=0.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Vingar! That's it! I couldn't quite put my thum... er, nose on it.
So this RTV caulk doesn't have the smell or what?
EDIT: Never mind. I shoud have read the rest of the posts. :D
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Cheap Tools at MyToolbox.netSee some of my work at AWorkOfWood.com
Edited 5/11/2008 7:43 pm by Ted W.
It is used extensively in metal applications (flashing, metal roofing, etc.) because the acetic acid in regular silicone is bad for metal contact.
Billy
Exactly. I've used a ton of it to glaze insulated units into metal frames. It is safer to use around the thermopane sealant.