Indian sandstone & fairly manky. The pressure wash (at 110 bar) gets the green stuff off ok but won’t shift the black spots. The only way I’ve managed to get 2 spotless slabs is to get on my knees & scrub with a wire brush, which wore the brush out in no time ( & fubared my knees even more)
I’ve tried Patio Magic & Jeyes fluid to little avail, what else works & would there be a discernible difference between a 110 bar & a 130 bar washer?

Help!

Just think of your biceps.

Some folk would pay a fortune in gym fees.

Get a man in

while you’re kneeling on the patio…

Do not and I repeat do not listen to anyone who suggests brick acid….

I used to use the “dirtblaster” lance on my patio, it’s a lot more effective than a standard lance. But nowhere near as good as one of these ..

https://www.amazon.co.uk/Kärcher-T-Racer-Cleaning-Pressure-Accessory/dp/B0000AITPN

Not met dirt yet that can remain in place for long under it.

No bicep usage in scrubbing a patio Colin. I’m sure getting a man in would involve using a more powerful washer or some magic chemical. All i need to know is which.

Jeyes Fluid, diluted to the proper strength for patio cleaning.

Apply it all over with a stiff brush, leave for half an hour, give it a very good scrub again with the brush then rinse off with a pressure washer or hose pipe.

Keep kids and pets well away. Its strong stuff. There’s nothing better than it from experience. I swear by the stuff. The smell keeps cats away too.

There are cheaper versions of that T Racer which do a grand job. Ours gets used annually on north facing patio, comes up like new

Have you tried bleach and washing up liquid in hot water? Pour on from your bucket leave for a minute then use a stiff yard brush.
Works on my slabs (haven’t got any Indian sandstone though, test it on an inconspicuous area).

Here
And as people rarely listen on here do take note, …………DO NOT USE BRICK ACID….
on Indian sandstone. You’ve basically left it too long between cleaning. I don’t like to link to paving expert often as I sometimes think differently but this is bang on.

As above paving expert is the place. Rogers jollop is the concoction.
http://www.pavingexpert.com/cgi-bin/ib3/ikonboard.cgi?s=e40006f6087c37378fc7cdb9d3d16261;act=ST;f=2;t=11988;&#top

What’s the minimum spec steam cleaner I need for a 20 foot by 30 patio.
I’d like something really small to store.

We had one of those T racer things – completely useless, didn’t even touch the dirt. Only thing which works is the lance on a narrow (1cm) beam. Takes ages but gets the bricks back to looking brand new.

Can’t you put together a gang of inmates from your prison and get it sorted, Shawshank style ?

I use bleach. Wet the patio down, throw on a bottle of bleach and scrub in with a stiff yard brush, wait a while then hose off.
North facing garden here (which is why it became a patio) and the above method gets rid of green moss/algae, bird poo and general dirt.

Once cleaned put some sealer on it to slow down the dirtying process…………..

what about a VERY light blast with soda or walnut shell? Not sure I like the idea of pouring bleach and other nasty stuff all over the place and letting it run off to the environment. Tea tree oil works well for mildew around the house if caught soon enough but as with the acid you need to be very careful with sandstone.

Thanks for the replies fellas. According to Pavingexpert It’s actually lichen that I can’t shift cos it’s proper stubborn, I might nuke the patio from orbit, see if that works. 😕

Can’t you put together a gang of inmates from your prison and get it sorted, Shawshank style ?

Wouldn’t want any of those cranks near my house!

I’ve got Indian sandstone at the front of my house which is north facing and pressure wash it twice a year. People don’t realise how quickly it looks crap and the only solution I have is to do it very slowly at very high pressure.

Granite at the back that cleans beautifully.

A bleach solution sprayed on with a decent deflector nozzle sprayer and left rather than rinsed off works. It also means far less bleach being put down.

After this, a spray with MMC Pro twice a year will keep it clean.

I used a Nilfisk patio cleaner to get the algae off about once every six months.

As others have said, do not use any cleaners on sandstone or limestone, at least not without testing them first, some will turn your patio a lovely colour (orange, I think). As will walking certain lawn feeds across the patio, footstep stains anyone?!

Try rubbing it with wild mussels……..

Just bought a nilfisk c130 pressure washer to clean our patio.

I have about 90m square to clean,I tried it out on about 30m square this evening and it made short work of it,using the patio cleaning attachment.ill finish the rest off at the weekend

Try rubbing it with wild mussels……..

I tried that but they were mixed with stomach acid, still didn’t work.

Did our sandstone patio last week. Jet wash got the muck off, but the black spots remained.
Bleach scrubbed in, left for a couple of hours then rinsed, now it looks like new. All the black spots are gone.

Try brick acid.

Just try not to look at it. Go out on your bike instead.

When I have a dirty cushion, I just turn it over. Have you tried that?

Failing that, brick acid.

It’s now absolutely spotless & no chemicals used!

Go on then, how did you do that?
I have the dreaded black lichen and the only thing that seems to work is covering it up for a couple of months.

One of these type of things.

http://www.ebay.co.uk/itm/Kiam-KM3200P-7HP-Petrol-High-Pressure-Washer-3200-PSI-220-Bar-12-6l-m-INDUSTRIAL-/251789980773?hash=item3a9fda3465:g:2bUAAOSwuTxWCkt1