Hi,
I’ve been looking online for the last few weeks trying to find a solution to a problem I’ve had with a Black Limestone patio.
I run a small one man Landscaping company in Bedfordshire, I’ve recently laid a black Limestone patio approx.35m2..this has been my first Black Limestone patio to be laid, I’ve laid plenty of sandstone and honey coloured limestone but never black.
I’m fully aware it needs treating with kid gloves as it is easy to stain with cement whilst laying and its a big mistake to use acid for cleaning. I’ve also had so many conflicting stories with regards to sealing the product, some companies say to leave it a while others suggest sealing it before grouting.
I took the latter advice as I use Easyjoint grouting material, I’m sure you are aware of this product and my main concern was leaving any of the oil residue that can be left if not careful, I took the advice of Azpects who manufacture easy joint and sealed the patio prior to jointing. I used their own product easy seal limestone and slate sealer.
This was applied and left to dry over a weekend and then I applied the grouting material on the monday ( just to note I use easyjoint all the time) the sealer repelled the oil and water as I’d expected but when the water dried on the surface it has left a white stain, I’ve included some photos below.
The stains seem to be where any of the water sat, there is a fall built into the patio so most of it has run away but you still get wet areas remaining.
Obviously my customer isn’t happy about this, I’ve been onto Azpects and have asked them to look into it, they tell me its calcium deposits from the water and subsequent rain...because the sealer is working so well at the moment its not allowing water to transfer through the stone and when it dries/evaporates its leaving the white mark you see.
They suggested I use another of their products a mortar and calcium cleaner but with extreme caution as black limestone can obviously discolour once chemicals are applied, there has been some success but the stains are still visible…I’m obviously concerned about using a stronger mix due to the reasons above. I’ve been using a hand scrubbing brush at this stage, but I’m running out of ideas , I'm hoping someone may have some useful info and may be able to offer some advice?
Can you recommend any other cleaners to use on black limestone, pads etc for scrubbing , anything?? does Azpects answer of Calcium deposits sound feasible or not, I’ve done everything to the letter with all the products but I’m not getting anywhere…hope you can help.
I can honestly say I have never had any other problems like this occur on any stone I've used, I went into the project fully aware how 'delicate' black Limestone can be, I've had a bloody awful time of it all, I'm meticulous when working and have been racking my brain to see if its something I've done, I've followed all processes to the letter...safe to say I'll never,ever touch the bloody stuff again..Hope you can help.
Many Thanks
Darren
The Green Room
Patio after being jointed, looks lovely when wet.
Slabs after drying out, white marks all over
Views: 4245
Replies
Here are a few previous threads Darren:
https://landscapejuicenetwork.com/forum/topics/black-limestone-re-c...
https://landscapejuicenetwork.com/forum/topics/sealant-and-black-li...
https://landscapejuicenetwork.com/forum/topics/efflorescence
have laid this in my own garden, and since doing so will never offer this to a client. its a nightmare. the images you have seam to be the natural salts coming out of the lime stone which do go away eventually. with regards to sealing i tried a recommended one and whilst it did seal the paving i wouldnt say it left it with the black look more a darker shade of grey.