Limestone problem

[niloc85]

Hi All,

Im new to this forum and to gardening... I had a go at laying a patio, which I was surprised about how successful it was until it came to grouting. The grout left some stains! I tried to clean with an alkaline based solution and it didnt work. I read alot of people saying that acid based solutions are bad for limestone, but if only used to the stone for a very small amount of time and is then washed off it should be ok and remove the grout. Now most of the paving has a mist on it, bit like this http://www.pavingexpert.com/images/stone/black_limestone_acid01.jpg. I applied some much water to clean the area off but I guess the damage is done.

Is there anything I can do without replacing the paving? I wish I would have known I needed to seal the paving before starting. Maybe some lessons need to be learned in the expensive way. PLz help

[London Stone Paving]

Roger is the man to advise on this.
You can get rid of the misting but its a long and expensive process. How many m2 have you got? May be cheaper to relay.

Who told you that acid could be used if it was washed off quickly? The advice is completely incorrect.

[niloc85]

An old friend who is a landscaper, however after this I don't think I will be taking his advice! Its around 10m sq.... So not a cheap replacement, being new aswell I'm reluctant to!

Maybe if I do need to replace, I will look to replace with slate or something more manageable!

What is the process?

[London Stone Paving]

Don't take this as read and I am sure that Roger will be along to advise. From what I remember you need to re-hone the surface of the slabs and then seal. Got a ball park in my head of around £30 a metre

[RAPressureWashing]

niloc85

Can you post a photo on here or email me a couple of photos of the damage? they don't need to be close-ups just a couple of good angles. The whole of the patio will have to be done to balance up the damaged area.

You are right Steve, we do re-hone the surface after acid damage!!!!!