Bathrooms were gutted and redone in late 1998. MB shower (32″ x 40″) has 4″ wall tile and 2″ floor tile in white. The lowest wall tile in shower has a bullnose lip where it meets floor tile and, in some areas, the outer floor tile sits slightly above the “nose of the bull” and water just sits on the joint. The floor/wall joint grout cracked several months after completion. Wall tile is set on backer board and shower floor tile is set in “typical” reinforced mud over two sheets of 3/4″ plywood.
Tile contractor came back to fix cracks and his fix was to dig out grout at wall/floor joint and apply caulk. I see now that in most areas he did not completely dig out grout and I have a mix of grout and caulk arout the shower floor. Mold builds up after about a week or so and we dutifully clean it as best we can. This is getting old – fast.
I believe I need to dig out this joint again. What specific brand of caulk should I be using here and can any caulk stand up to the situation where water just sits on the joint ?
Thanks in advance
Eric S.
Replies
Is your bathroom well vented?????
My life is my practice!
http://CLIFFORDRENOVATIONS.COM
can any caulk stand up to the situation where water just sits on the joint ?
Not forever.
But try this: briskly scrub (but don't over do it) the area with very hot water and automatic dishwashing detergent (say 2 tablespoons / pint) and rinse.
I have found that it takes much longer for mold to reappear in areas cleaned that way.
Albert Einstein said it best:
“Problems,” he said, “cannot be solved at the same level of consciousness that created them.”
Your mileage may vary ....
Bob,
RE: mildew and mold. It is an awful problem here in Va. Even our glass windows will get a layer at times.
What are you experiencing with Hardie board? Is it less prone to mildew than the composition (pressed cardboard) beaded siding many of our homes have?
People around here are going to vinyl, not because they like it, but because they are tired of having homes clorox/pressure washed 2x/ year, and then paintig ever 4-5 years. The vinyl gets dusty and a pollen coating, but is fairly easy to wash compared to the old siding board.
About 20 years ago, I got a 2 part industrial coating (6-hour pot life), and painted our siding. The paint was designed for chemical tank farms, like clorine storage facilities, but the company reformulated a batch for me to try of siding, rather than steel. Nothing can hurt it short of mechanical damage. Couldn't even clean a brush, cost too much for chems.
The siding looked good for a couple of years, and then began to mildew.
Tilex and a brush would clean it nicely, but had to be done 1-2 times a year. I finally gave up in the mid '90s, and had vinyl installed.
I wanted to get it up prior to the rotting and swelling many neighbors have, who are now facing covering the rot with fanfold and vinyl.
So back to my question, how is Hardie doing here in the Mid- Atlantic states?
PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home
I am not sure your shower is built up to snuff, even though it is fairly new. If installed with a preslope, water should drain very nicely at the floor wall juncture. Bullnose tile haver no place at that juncture either, you actually want the opposite, a cove piece there if you can, or at least straight tile. That bullnose actually directs water into the joint.
So I am suspecting no preslope on the pan and a lousy bottom row of tiles.
That having been said, if you want to attack the mold and not the cause, I would dig out that joint completely with ice picks, dremel tools, whatever. I would kill the mold with a strong bleach solution. I would then let the shower dry out with a fan in place for week. You might even want to invest in a heat gun or hand dryer to really cook that joint.
Install 100% silicone caulk. This is as waterproof as it gets.
My second choice would be a sanded caulk.
You may also want to do some maintenance after you shower. Take a towel and lightly wipe down the shower, especially at that juncture.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
Edited 10/27/2003 12:45:47 PM ET by Boris Yeltsin
Paul
I've used "Hardie Board" on four houses I've built here in North Central Ala. in the last 2 years (including my own) and so far have experienced no mildew problems. Neighboring homes with vinyl siding are having problems with mildew and have borrowed my pressure washer to clean it. I used a high quality flat oil base paint for the siding and a gloss for trim. I'd be interested to hear from anyone who has either applied the CFB or has had it on a building for a longer period to see how it is performing for them??
Bill
Oil based paint should not be used on cementitious products like Hardie materials. The alkalai in the material reacts with oils in the paints to form soap, which will reduce the bond between paint and the siding. The manufacturer specifically recommends against it.
Speaking of mold on the exterior, I've never heard of mold on windows. It must be quite a place. I wonder if the new self-cleaning glass would work there.
never heard of mold on windows. It is an everyday happening here, heat, humitiy, rain everyday. everybody has couple gallon of bleach in the garage.
The siding looked good for a couple of years, and then began to mildew. Tilex and a brush would clean it nicely, but had to be done 1-2 times a year. I finally gave up in the mid '90s, and had vinyl installed.
Hi Paul,
Here in Charlottesville I've found only one surface that absolutely won't grow mold. Came on mahogany furniture that a customer had. Furniture's now 15 yrs old, lives outside all year. Sun doesn't bother it either. Turns out to be boat hull paint with some sort of incredible -cide in it. Didn't apparently harm their dog when he chewed the hell out of it. The sheet that came with the can I bought to respray, said "breathe it and die". Pretty incredible stuff. Also very expensive. Looks like a plastic coating on the mahogany. Not my taste, but it works.
Hmmm, that's not quite right. I have yet to see anything grow on our copper siding. That might be the ticket.
We have no mildew problem in our house, but that's due to conscientious shower venting coupled with humidity monitoring and control to keep it down around 50%rh. The heat pump water heater helps immensely with its byproduct of dry, cool air. Just got an electric bill, 30 days total 840 kwh ($79.65) for our 20k cu ft with almost constant dehumidification (no ac) and my shop with large tools.PAHS Designer/Builder- Bury it!
I think some of the silicones contain a mildewcide, others don't. I think the ones labeled for bath use have the mildewcide. Check the labels.
Do it right, or do it twice.
You might want to try keeping a spray bottle of a bleach-water solution handy and lightly misting the area once a day after showering.
Thanks for responses guys:
For Andy C. - bathrooms are very well vented to outside gable wall
for Bob W. - will try your solution after a thorough Tilex treatment.
for ELCID - I'll read the labels on the new caulk
for GOLDHILLER - essentially I've been doing that (with Tilex) but not every day
Eric S.
Use epoxy-grout. It won't support mould. Its a PITA to install but you will never have to do grout maintenance again.
Made by Laticrete Corp. Naugatuck Ct.
OK - Thanks. I'm off to the Laticrete web site. If you can think of anything I should know other than "following their directions," would appreciate a follow up. Is the product Latapoxy SP-100 the one you were referring to?
I assume that before I use this epoxy grout, I need to clean out ALL traces of grout/caulk between the wall and floor.
Eric S.
Edited 6/13/2004 6:56 pm ET by Eric Svendson
I cant remember but Latapoxy sounds familiar.
I used it on a porcelain tile and I had a hard time getting the haze off the tile. I called Laticrete tech rep and he told me to use automatic dishwashing detergent and a scotchbrite pad. That worked fine with a lot of elbow grease.
And yeah, the old grout has to go. The epoxy grout is packaged in small amounts so you mix often depending on your tile size and spacing. I had a 200 sq.ft. floor using 13" tiles with 1/4" or less spacing. It took 24 packages of grout.