Have you tried a high pressure cleaner ?

If anything do not use bleach as bleach can give yellow brownish discolouring !

I would use bleach and see if that works!

A good scrub with hot soapy water,, for more stubborn stains, make a bicarb / vinegar paste pour onto tiles allow to sit briefly prior to cleaning with hot soapy water.

Bicarb, vinegar and lemon juice mixed with water – will come up a treat =)

thankyou mums you have all given me something to think about

If you use chlorine try it on a patch first. It depends on the surface whether or not it is advisable. Make sure you wear goggles and breathing mask, especially if you have breathing issues at all. I find the fumes from Chlorine stings my eyes, and I don’t even go in the water. The chlorine we can buy is not the same strength as is used in our drinking water. There are other products listed that would rather try. If you are unfortunate to get any chlorine on your skin at that strength I am sure it would burn it. Some people are allergic to chlorine too. I would try the one listed that is not acidic at all. It sounds a lot safer to use. I hope whatever you choose to use is successful.

try bleach but if the mould is in the grout, it is impossible to clean and will have to be removed

We have outdoor tiles, worst idea ever!!! Get yourself a scrubbing brush on a stick. I like to use washing powder but my dad like dishwashing liquid Happy scrubbing. lol

Oh & I say NO TO CHLORINE, IT CAN DISCOLOUR THE TILES. Trust me, I have been a bond cleaner for years & have seen what chlorine can do.

if you have a high pressure wash, (something like a Karcher) use this. Just be careful not to hold nozzle to close to the area while cleaning

thankyou so much ladys for your help, it is greatly appreciated

Wet & Forget
Wet & Forget has a unique combination of biodegradable selective surfactants for moss, mould and lichen removal on absolutely any exterior surface. When diluted with water and applied, it immediately attacks that unsightly moss, mould and grime. Then Mother Nature takes over. The weathering process gently takes the decomposing material away bit by bit without scouring the surface it has infested. Wet & Forget is the safest, most effective way of removing moss & mould from ANY exterior surface.

Non caustic. Non acidic
No bleach. No water blasting.
No elbow grease.

thanks guys I am getting some great ideas here

Wet & Forget works really well on stains & mould, we used it on our bricks also!

Might be a good idea to get some expert advice. I would be careful about using chemicals and again get some advice around cleaning with chemicals. Might be a good idea to get a professional clean for the first clean and then you can follow DIY cleaning guidelines for subsequent cleaning of the tiles.

I agree wtih MOM109463. I buy 100% Chlorine put it in a Pressure Pump Pack with adjustable nozzle (like the sprayer you get when spraying your grass of weeds and Bindi) Leave for 10-20 minutes and then use a high pressure hose/washer. You will get great results. Please use a pair of safety glasses and mask.

carefully with a broom, mix up a chlorine and water mixture and brush it on, wear old clothes as it will bleach clothes, but a couple of cups of chlorine in a bucket of water is more than sufficient, leave on for a few minutes depending on how bad the staining is then hose of with as high a pressure hose that you have, this will remove mold and stains, and make the nice and white. do a few square meters at a time as it wil get ahead of you but it works on concrete as well with gum tree stains. keep well diluted when rinsing off so that it does not hurt any delicate plants but It is only chlorine which is in our tap water and drinking water anyway. many driveway cleaning people use the same method.