Grotty patio slabs - how to clean?

[cleaningandclearing]

We have a garden mostly laid to patio but it was all laid about 10 years ago so it’s all looking a bit tired now.
DH usually jet washes the slabs as they go black over the winter but every time he does it they seem to get a bit more damaged.

is there a patio slab cleaner that brings them back to their old beige colour? Or can they be painted and sealed? Or should we just jet wash them? I’d like the idea of painting them a lighter colour if possible.

Any ideas to improve them would be appreciated thank you

I jet wash ours. I have also bought a product to use on them to keep the mildew / green slime at bay (might be patio magic? It’s in the shed). I’ve not used the product yet but hopeful!

You'd need to clean them before you seal them, or you'd only be sealing in the dirt anyway.

First off, I'd try eco-friendly washing up liquid and scrubbing with a stiff brush or broom. Cheap, cheerful, should make difference.

If that wasn't enough I'd look at D/2 biological solution (the stuff used for cleaning gravestones without damaging the stone).

If a jet wash doesn't solve it, you have to scrub them with stuff. It's a grim job.
https://patioblackspotremoval.com/products/patio-black-spot-remover-for-natural-stone?variant=41653961130224&country=GB&currency=GBP&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gad_source=1&gad_campaignid=23215438929&gbraid=0AAAAAoVfShLQeXS2UGLKdGBy3DGgNenPg&gclid=Cj0KCQiAwYrNBhDcARIsAGo3u330hYOlaOaVfdDBCDAzvKx0L-YKFGmMeyX8dGcvtinEV8aptdqWYvcaAoF-EALw_wcB

thank you so much, I’ll have a look at that

Can I jump in and ask how you clean the grout between the slabs? Spent a fortune having ours laid last year and they are looking green but I'm scared to jetwash them in case it blasts the cement out of the joints and the gaps then fill up with weeds. Someone recommended a brush on sand that restores colour and removes weeds and green , which you then brush off or is washed off by rain, but he can't remember what it's called so I don't know what to buy...

I use wet and forget. It was brilliant on the corner patio. We’ve bought more for the back patio.

I always use bleach and hot water to bring mine up. Not very strong but slosh it on and leave it wet. By the next day all the algae has gone and I can just wash them off

@Thatsanotherfinemess1 is it Sika FastFix? That’s what our landscaper used.

Another vote for Wet and Forget ... i'll admit I was dubious, but the difference it's made is amazing