white marks on my newly sealed black limestone - TilersForums.com

[lucysummers]

Just had 45m2 of black strata limestone laid, we cleaned it last week and allowed it to dry and then sealed it the next day with Thompsons clear limestone sealer, it dried for about 6 hours and then came the rain. I have now a patio covered with what looks like white salt marks and it looks horrendous. I called back the guy who laid it, who brought round some patio cleaner that contained acid, we tested a couple of the slabs, seemed ok so proceeded to do the top end of the patio (where the shed shall be laid) it has now taken the colour out of the slabs and left them greyish white. What should I do next?

 

[DHTiling]

Hi lucy..


It is water bloom... and needs removing

but the use of acid will make it worse.. and grey the slabs..

You need to use LTP Grimex and give the slabs a good clean.... then leave to dry , once dry then use 2 coats of LTP stone oil and then 2 coats of LTP colour enhancer , this should give you a really nice finish.

 

[lucysummers]

Thanks dave for your speedy reply, when you mean the colour enhancer is that the intensifier or the mattstone product? I notice there are 2 mattstones one with H2o so which is best to use? As I mentioned we only applied the acidy stuff to the top area of the patio which seperated by a step from the bottom half of the patio, which we also sealed and has the whitemarks on but we didnt put the acid cleaner on this bit thank god, so this part of the patio still has the thompsons sealer on it with white marks, should I treat this area the sames as the top area? Its only the top area of the patio that we cleansed to see how it would come up and this is where the limestone has gone grey so the process that you have mentioned above should i do it on the whole of the patio regardless? It has cost us £4000 and at the moment I feel distraut with the whole thing, I feel as though it is ruined, I wanted to post some pictures to show you but not sure how to on here

 

[lucysummers]

this photo is how it looked before with marks on


this is the top bit of
patio that we cleaned

 

[DHTiling]

Morning

I have a method statement on the main pc, I will post it once I get on that later but yes it can be saved


Sent from my iPhone

 

[lucysummers]

hi Dave, much appreciated, please can you tell me what I should be applying to the top patio thats has been sealed, then went patchy and now has been washed with acid and lost its colour and B, what i should do with the bottom patio that was also sealed at the same time but is covered with marks also but hasnt been washed with the acid. Plus the method, pulling my hair out! I have located a place close to home where I can get the products, thanks Lucy

 

[DHTiling]

It needs removing , I will switch the pc on and post the method
Sat in garden at present


Sent from my iPhone

 

[lucysummers]

ok thank you so much, off to get the grimex this afternoon, enjoy the sun:smilewinkgrin:

 

[DHTiling]

Hi Lucy..

This is a method statement from LTP for the cleaning of a patio just like yours with same acid washing etc...

Wash surfaces thoroughly with a strong solution of LTP Grimex. This will help to break down and remove the sealer from the stone.

Use undiluted onto the surface of the granite and then agitate immediately using a black pad or stiff brush, adding a little water whilst scrubbing. Do this for 20 - 30 minutes and rinse well with plenty of clean fresh water. Leave to dry 30 minutes.

While the stone is still saturated with moisture we would suggest then washing the surface of the stone with a medium strength solution of acid in an attempt to even the discoloration of the stone caused by acid etching from the cement cleaners that were used.

Apply a 1 : 3 solution of LTP Grout Stain remover to the surface of the stone and scrub evenly over the surface, Leave for 5 minutes, agitate again and then rinse thoroughly with plenty of clean fresh water.

Leave to dry for 48 - 72 hours.

To help restore the colour of the stone we would like to suggest LTP Stone Oil to deepen the colour followed by LTP Colour Intensifier for extra protection.

Apply these products first in an inconspicuous area to help establish the optimum number of coats. Probably Stone Oil 2, Colour Intensifier 2.

Allow 4 hours drying time between each application.

 

[lucysummers]

thanks Dave should i follow this process to for the bottom part of the patio, which is also stained with watermarks, but wasnt cleanes with the acidy stuff, its just got the sealant on put i think we need to start from scratch. Just looked at another post from april that you replied to 'is my patio ruined' and her pictures are amazing, thank you