I am new to the forum, and am impressed by the breadth and depth of information on here.
My question is in connection with our Stonemarket Riven patios which were laid by a landscaper approx 18 months ago.
I am pleased with the look of the flags, which are the black 'Old London' type, but I am still getting loads of black dust coming off them. This a real pain with the kids getting black feet etc.
I have tried cleaning with a low pressure wash (Stonemarket don't recommend jet washing) and have brushed them with a stiff brush repeatedly, however the dust keeps coming off.
As yet I haven't attempted to seal them with anything.
My questions are -
1. should the flags still be dusting after this length of time? and 2.what sort of sealant would you recommend to stop it?
No, they shouldn't be dusting. This usually only happens if they've been treated with acid/brick cleaner, or pressure washed, both of which damage the surface layer and make it friable. There are manufacturing issues that could cause it also; you could try consulting Stonemarket, as their warranty doesn't have a stated time limitation. I wouldn't hold out too much hope on that score though!
Eureco in West Sussex make a good water based sealer. For Solvent based, try Worldpoint.
Mouldmaker - do you rate that Eureco jollop? I've tried it on wet-cast products and thought it was pretty poor. It didn't prevent penetration of thin oils (paraffin and lighter fluid), and didn't protect against burger fat. I was unimpressed and surprised to find Stonemarket endorsing it.
