Patio, slab, concrete cleaner

Can anyone recommend a cleaner for slabs? Some are buff and some are grey and need a really good clean, I know can jetwash them but I don't think that alone will do the job.

 

I used to use my jetwash on our York stone patios and paths. Always a pain, 'cos you have to "suit up."
I now use "Wet & Forget." "It does what is says on the tin."

A neighbour used a pump spray with a mild solution of bleach. This was very effective on his drive which was ordinary concrete paving slabs.

 

I use sodium hypochlorite , diluted 2 to 1 . Its chlorine used as a swimming pool biocide. Basically a very strong bleach , so care is needed . Goggles and gloves . Costs about £2 a litre , apply with a hand pressure spray. Works incredibly well , test area first though. Lots of how too videos on Youtube
Sodium Hypochlorite 14-15% Patio Cleaner / Swimming Pool Chlorine - 10 Litre | eBay

 

My yard is slabbed I did buy some patio cleaner but found a good strong bleach about £1 and a hard strong yard brush tends to do the job better so thats what i use now

The garden path and at the bottom of the garden is pattened black concrete most cleaners would clean it but they would also remove some of the colour so i use bucket of water / strong washing up liqiud and hard brush it cleans the concrete and birds poo as well

 

Everybody, thanks for your helpful advice, wet and forget had been one I'd seen that had great reviews but it's always better when people you trust tell you it works, got some scraps of slab so I'll probably have a go at all your idea's, thanks again

 

Cop this........
Patio Black Spot Remover 4 litres for Block Pavers

 

Hi shiny your patio nice nice pics