SmartSeal Patio Cleaner Xtreme - 2 x 5L - Powerful Black Spot Remover Patio Cleaner & Rapid Mould Lichen and Algae Remover for Cleaning Stone Paving, Concrete, Sandstone, Porcelain, Slate & Granite

This stuff is brilliant! Works so easily on dirty, spotted patio slabs. Just spray on using a watering can and brush round to ensure complete coverage. Leave for 30 minutes to an hour and then wash off. Needs hardly any scrubbing and the results are stunning (see photo - before & after). Better than anything else we’ve tried!

This stuff is excellent. Follow the instructions and it works wonders on patios. It doesn’t entirely deal with black spots, but it transforms old dirty slabs, with very little effort. I also tried it on composite decking, worked just as well, looks like new. Just be careful getting it on your hands or splashing it on your face or whatever - it does burn a bit. It’s similar to a really really strong bleach. Thoroughly recommend.

Works well. Expensive and I needed more than I thought I would, but it definitely worked well.

I don’t often leave reviews, but I purchased this, and didn’t think it would do much. I had a patio full of gunk and algae that hadn’t been touched in years, so I used a sprayer to apply this cleaner (I used 2/3 cleaner 1/3 water dilution so it was a bit stronger). And then left it for roughly 2 hours before using my patio attachment on the jet wash and the difference this made! Wow! I’m very impressed! There’s was no need to scrub in the solution I just let it sit and get to work. The only thing to bear in mind though is that it does smell quite strong…

Does what it says on the label. My sandstone patio came up clean even after years of neglect.

The pictures speak for themselves, I’m amazed at how well my patio slabs have cleaned up. I added it neat to one slab at a time and wire brushed each slab, left for at least half an hour and then jet washed off, taking advantage of some sunshine yesterday. I couldn’t get the top off the container though so asked my son for help but after that it was simple and straightforward, also kills the weeds that were coming through. Because I put it on neat it didn’t go as far as I wanted it to but will definitely order another 5L to finish off.

Was fairly dubious as with most claims however, I found this stuff to actually do the job and cut through some of the most stubborn stains on my Indian Stone Paving. I sprayed it on with a garden sprayer, left for an hour then jet washed. Some of the stains were still there so a re-treated those areas whilst concentrating on other sections, its a fairly large patio. When I came back to look at them it had dissolved the black marks and staining. Patio looks extremely good. One word of warning is that this stuff contains bleach so I have ruined a pair of Jogging bottoms with spray back. Unless you like the pink streak look :) Use plenty of water if your near plants or the lawn but after a week I have had no bad reactions and the patio looks great. Only took a star away as it is expensive, I used all of it. And yes I would buy this again

This stuff is the mutts nuts! It will bleach and clothes and mark any surface it comes into contact with but it really cleans a dirty patio.

Absolutely unbelievable. This works so well and so so quickly. Used on my patio which had lots of black spots and dirt. It came out like new. A little brush after application and it’s brilliant. Very fast delivery working 2 days.