Cleaning some old outdoor tiles

RHemmings

Hi all. I'm looking into how I can clean some old outdoor tiles. These tiles are from the church my wife and I attend. I don't know how old the tiles are: the church was established in 1708, but I have absolutely no idea of its architectual history. But, these could be hundreds of years old for all I know. 



The minister says that some people are concerned about chemicals being used on them. I was thinking of using a jet pressure wash on them, but read that too high pressure or being too close could damage tiles. The simplest way forward is perhaps plain water and a scrubbing brush. Any ideas/advice/hints? 

Brie

try a bit of bicarb and either lemon juice or vinegar in a small area with a not too stiff brush or maybe just a dish sponge that has that plastic scrapey side.  (Lidl 6 pack for under £1 I believe)  (lemon juice smells nicer but could leave it a bit sticky, vinegar works work for cleaning but it will smell like a chippy!!!)

don't use this near vegetation you don't wan to kill.  I use vinegar to kill the grass/weeds that grown between the patio paving stones. 

I def wouldn't want to try jet washing them!  

And remind people that once all the grit is cleaned off them they may be a bit slippy compared to normal.

Sarahspangles

They look like Victorian encaustic tiles. You can get proprietary cleaners and sealers. Don’t use any acidic products on them because they’re not sealed like indoor tiles.

RHemmings

Thanks. There are cleaners said to be suitable for encaustic tiles, such as the following. 



There are also sealers, e.g.:



But, this is getting a bit complex. If they were my own tiles, I would be more confident of going ahead. I'm responding to a comment that there may have been some algae growing on the tiles which make them slippery when they are wet. 

BTW: If I cleaned them, I would go when there isn't a service (but the minister is present) so that people wouldn't be walking on them before they are dry. 

FreeBear

Old fashion soap and a scrubbing brush plus plenty of water. Steer well clear of harsh chemicals and/or high pressure water.

Eldi_Dos

Get  tub of Swarfega Hand Cleaner and try a test in the least noticable tile, with a old toothbrush.
If you are happy go ahead and wash all the tiles then rub in the Swarfega and leave for half a hour  then give them a good scrub with a stiff brush and then rinse off.The hand cleaner is designed to take off oil,grime,tar ect so hopfully should improve appearance of tiles.
You can get tubs in Halfords for £12.99

Sarahspangles

RHemmings said:

Thanks. There are cleaners said to be suitable for encaustic tiles, such as the following. 

There are also sealers, e.g.:

But, this is getting a bit complex. If they were my own tiles, I would be more confident of going ahead. I'm responding to a comment that there may have been some algae growing on the tiles which make them slippery when they are wet. 

BTW: If I cleaned them, I would go when there isn't a service (but the minister is present) so that people wouldn't be walking on them before they are dry. 

It’s a long time since I had encaustic tiles, they’re very hard wearing so you get them on paths and in porches of Victorian and Edwardian houses. They don’t grow algae/slime unless there’s something in the surface for that to grow on. I’d clean them with something like the neutral cleaner you found, and decide later about sealing.