Black Mould on Silicon - How to Replace and Prevent?

mrobsessed

Hi,

I had a shower installed 2 and half years ago but now the white silicon where the base meet the tiles has black marks on the silicon that is mildew/mould. This seemingly cannot be removed by cleaning - is there a way of removing the marks without replacing the silicon completely?

if the silicon does have to be removed what is the best way to go about it? I read that it can simply be removed by cutting most of it out with a very sharp Stanley knife and scraping the remainder away off the ceramic/tiles. Is there an easier or better way or is it just a matter of taking the time to painstakingly remove every scrap?

Once the old silicone has been removed what's the next step? Should the area be degreased before adding the new silicone, and with what?

Bathroom silicone is marketed as 'mould resistant' but is any silicone really mould proof? Is there any brand of silicone that doesn't eventually get mouldy or is mould unavoidable in silicone that is constantly damp?

Any help with this annoyance would be appreciated!

Thanks

vax2002

Have you tried neat bleach and leave it on ?

ankspon

All silicone gets mould over the years,it is due to soap scum,shampoos,body wash and heat in the room etc.It will stay away longer if cleaned properly and regularly but it comes back to us all.You can buy a sealant remover tool for a couple of quid,remove any excess bits and with the area clean and dry put new silicone down and make sure it's for bathrooms.

Leif

vax2002 wrote: »

Have you tried neat bleach and leave it on ?

It works well on silicone sealant, just be careful if there are coloured plastics or paint as the silicone might bleach them, or even damage plastic. Test a small area first.

Maz1963

I bought some HG Mould spray from Lakeland a while back. I've mainly used it on the grout around the shower tiles and it's excellent, just dissolves the dirt away very quickly. I tried it on mould on the silicone seal between my kitchen sink and granite work surface, and it seemed to work there, but think it has discoloured the stainless steel a little so you need to be careful, it's obviously powerful stuff! I would guess it should work very well on any mould in the shower. I had the seal around the kitchen sink replaced a couple of years back because of mould, and it's building up again on what was supposed to be better stuff, so I'm not sure if there's anything out there that completely resists the mould.

lovebooks_2

Neat bleach, or Dettol mould and mildew remover, works for me.

mrobsessed

The Bleach/mould remover ideas sounds promising and worth a try - otherwise I'll go the whole hog and replace the silicone.

Many thanks for all your help!

vax2002

If you do have to replace it, you will need to find something heavy to stand in the shower base, bags of sand ect whilst you apply and leave to set, other wise when you step in the base it will split.

MX5huggy

If you end up replacing, cut out the old then use silicone remover to get the last off, give it a good clean.

Then use Dow Corning 785 to replace all good trade places should sell it.

http://www.screwfix.com/p/dow-corning-785-white/58308

WestonDave

Also when you put the new stuff on make sure it is really really smooth. The fewer dents and bubbles in it, the less places for water to sit and that is where the mould tends to start.

vax2002

Decent tilers carry a bucket and a kettle and stand the unopened tubes in hot water for a few mins before applying the sealant, it lowers the viscosity and makes it flow and lay smooth.
dry the tube cut the end and fit the nozzle, which you dont put in the water...