sandstone flags

[lorien]

we have laid reclaimed sandstone flags in our conservatory and wonder whether to clean them and if so with what. The patina is great, but there are paint spots on them which if sanded off leave a clean mark. I am aware how porous they are and wonder if brick acid would be too harsh. any comments?

[J H Clifford]

I've cleaned up quite a few reclaimed flags over the years, using different methods for different types of flags, and for different stains and marks.

If you can let me know what the reclaimed flags are, and perhaps email a couple of photo's to me - john@westminsterstone.com - I'll see if I can help with a solution.

Cheers!

[84-1093879891]

Brick acid tends not to work with paint spots, as it is intended to react with cement- or lime-based contaminants. Applying an acid wash can give a whole, fresh look to some types of stone paving, but you need to be careful as certain types of stone - and, from experience, it does seem to be the imported Indian sandstone that is particulary at risk - can develop a nasty orange-rusty colouring when washed with even a diluted acid. As ever, try it on a small discreet corner first.

Piant stripper, though, does seem to be more effective and less risky. It's bloody nasty stuff, so make sure you've got gloves and goggles on, and you're not wearing your party frock. Work the jollop into the paint spots with an old paintbrush, and wash off with copious amounts of water as the paint begins to dissolve.

Good luck!