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How to tackle mildew on bath seal?

Sasha

Fine, thank you
Messages
17,863
Location
UK
As far as I'm aware I don't have issues with sensitives to mould but for years there has been bad mildew in the bath sealant in my flat - not just a few spots, it's very black. I'm sick of looking at it and want to fix it. I'm wondering if there are any issues I should be aware of, either healthwise or in terms of an effective solution to getting rid of the mildew.

I've read several DIY threads on this topic on various forums and many say that you can't clean the mildew off the sealant because it has grown through it (I've tried a specialist mildew remover and it had no effect at all). Some say you have to strip the sealant off and resign yourself to renewing it every year or so. Some say you can lay plastic strips on top of it but others say the mildew is still growing underneath.

I don't have the energy to fix the problem myself so would get a plumber in.

Any views on what's both an effective solution and a healthy one?
 

Mij

Messages
2,353
I don't have advice to give as far as fixing this but to prevent it from building up more mix 25 drops of Tea Tree oil in 2 cups of water in a spray bottle and spritz your tiles after you shower. This prevents any bacteria or mold from taking hold. I've been doing this for years and it keeps my bathroom fresh and mold free.
 

snowathlete

Senior Member
Messages
5,374
Location
UK
Replace it, but get a handyman to do it rather than a plumber as that will likely be cheaper.
I know you can buy some sealants that have anti fungals in them, I don't know how good they are but might be worth looking into.
 

Sasha

Fine, thank you
Messages
17,863
Location
UK
I don't have advice to give as far as fixing this but to prevent it from building up more mix 25 drops of Tea Tree oil in 2 cups of water in a spray bottle and spritz your tiles after you shower. This prevents any bacteria or mold from taking hold. I've been doing this for years and it keeps my bathroom fresh and mold free.
That's interesting - some people suggest wiping the sealant free of moisture after each shower but using an antifungal spray is an interesting idea.
 

Sasha

Fine, thank you
Messages
17,863
Location
UK
Replace it, but get a handyman to do it rather than a plumber as that will likely be cheaper.
I know you can buy some sealants that have anti fungals in them, I don't know how good they are but might be worth looking into.

Thanks, snow - I'm getting a plumber in for some other stuff so thought I'd just not have the aggro of finding another tradesman but I'll get a quote.

On the DIY forums people have tried the antifungal sealants but they don't seem to work. It seems to be one of those areas where there are a lot of claims for stuff that works and it doesn't. :p
 

peggy-sue

Senior Member
Messages
2,623
Location
Scotland
Sealant is actually very easy to replace. It comes in a big "gun-type" bottle with a nozzle to apply it.

The "secret" of getting it even and properly sealed to the bath

is to wet your thumb with a bit of slightly diluted dish-washing liquid (which stops the sealant sticking to you)

and to very, very gently, slowly and lightly run your thumb over the surface to create the proper sort of seal.

Sodium bicarbonate is a great cleaner and will kill smells and bacteria. It's not bad for mildew either, but as has been said, if mildew is already in the sealant, you need to get rid of it.
An antifungal one might be a good idea - but get somebody else to do it if you have any sensitivity issues, or reconsider whether issues with antifungal chemicals might preclude this.
 

Sasha

Fine, thank you
Messages
17,863
Location
UK
you can also get this stuff. No idea if it is any good, but its easy to apply yourself by the looks of things.
http://www.polycell.co.uk/products/polycell_sealant_strip_for_kitchen_and_bathrooms.jsp

Thanks, snow - that's one of the ones I had a look at but I'm not sure what to make about people's comments that the mildew is still growing underneath. I'm not sure how much of a health risk mildew is (to someone who doesn't apparently have a sensitivity to it). My mother has had one of these sealant strips on her bath for probably 20 years now and it's still squeaky clean (on the surface, at any rate!).

I read on another DIY thread just now that if you apply one of these mildew sprays to the seal by soaking toilet paper in it and leaving it overnight it will clear it so I'm experimenting with that.

Such a human universal, this, that you'd think there'd be a well-established solution!
 

Min

Guest
Messages
1,387
Location
UK
The only reliable way to remove the mould is to replace the sealant, although I have had good results with leaving cotton wool pads soaked in bleach on the mould overnight (this does not remove the staining the mould leaves behind).

If you are replacing the sealant, fill the bath with water first so there's no cracking of sealant from the weight of the water if the bath is not filled until afterwards.
 

Sasha

Fine, thank you
Messages
17,863
Location
UK
I have had good results with leaving cotton wool pads soaked in bleach on the mould overnight

I've had the loo paper soaked in mildew cleaner on there for a couple of hours now and some did actually come off onto the end of a toothbrush (though there's so much of it that it didn't make any difference in what was left behind!). I wonder what it will look like in a few hours. :alien:
 

Sean

Senior Member
Messages
7,378
Hydrogen peroxide is often good at that sort of stuff. Has the advantage of being a liquid, so it gets into fine recesses that a brush or sponge can't.

Or just replace it. But it is one of those jobs you need to do right.
 
Messages
646
Any views on what's both an effective solution and a healthy one?
Whatever the manafacters claim (25 year lifetime etc) in most cases (i.e where there's less than perfect air circulation) mould will be problem and the sealant will need replacing every few years.

Although, for those whose hands work OK and can concentrate for the time the job takes (needs to be a single operation to avoid flaws) the solvents used in the sealants are foul, so anyone who finds smells/chemicals an issue - be forewarned if you are aiming to do this job yourself, or need to use the area being worked on for at least a couple of hours after the sealant has gone down. The problem is compounded by the fact that the most effective sealants are spirit, not water based, so to give a finish to to the 'bead' you need to use white spirit.

The only effective mould removers are bleaches of one kind or another - Hydrogen peroxide is not too offensive, but again anyone with sensitivities can find scrubbing with bleach a bit of challenge - using a DIY face mask can help. Using preventers like Tea Tree Oil can keep the moulds at bay for a while, but there's a danger of selective breeding and you can end up with only the most resilient strains being active and resistent to any remover. Ensuring good ventilation (almost impossible) is the only way to limit mould growth in the long term.

IVI
 

peggy-sue

Senior Member
Messages
2,623
Location
Scotland
There are sensitivity issues with tea tree oil too. I'm horribly allergic to it and the smell makes me choke.

We've got wet wall in the bathroom, rather than tiles. After showering, I (or myOH) use a flexible plastic doofer for flattening wallpaper to swipe all the condensation from the walls back into the bath. This really helps to keep airborne moisture down.
 
Messages
29
Location
Toronto, Ontario
you never want to use bleach or ammonia as they are highly toxic. Hydrogen peroxide is your best bet but better to prevent it than have to clean it. For a chemical free caulk use only 100% aquarium grade silicone, as it is the only non-toxic caulking. Grout should be sealed with a non-toxic grout sealer to prevent mould in the grout as that seems impossible to clean once it's in there. http://mychemicalfreehouse.blogspot.ca/2013/02/a-non-toxic-bathroom.html
 

sianrecovery

Senior Member
Messages
828
Location
Manchester UK
I had a mold expert survey my flat, and he - I am sensitive to mold, and he knew that - told me to not use bleach to kill mold, because the spores are more toxic as they die. He suggested getting someone else to replace it. Failing that, to wash it down with detergent and let it dry, before covering it with a mold resistent paint. He said repeated applications of bleach do not completely kill the mold anyway, just make it more hardy.
Not sure if that's good advice or not, but passing it on anyway.