Posted: Fri Apr 15, 2011 1:47 am
I have had (lightly) polished limestone tiles (15 mm) laid at 4mm intervals on a 2 inch mortar (sharp sand & cement) bed on 4 inch compacted hardcore sub base. Its all gone down well and is nice and solid. My priority now is to make the right choices to ensure it lasts well:
My main concern is frost damage, the limestone seems to be more porous than I had expected and i want to reduce any chance over the winter of water being absorbed into the stone then freezing and rupturing the tiles.
As I see it I have two choices: I either use a permeable sand/cement based grout to help drain water off and into the ground or I seal the limestone and use a waterproof grout to prevent water (from above) ever entering the stone in the first place.
Apart from the obvious disadvantage that a waterproof system will drain poorly as it relies purely on gradient drainage and evaporation to clear surface rain. Are there any other considerations or words of warning people can offer?
I am planning to do a worst case scenario "wet freezer test" on a spare piece of tile to try to gauge how concerned I should be about frost damage.
My main concern is frost damage, the limestone seems to be more porous than I had expected and i want to reduce any chance over the winter of water being absorbed into the stone then freezing and rupturing the tiles.
As I see it I have two choices: I either use a permeable sand/cement based grout to help drain water off and into the ground or I seal the limestone and use a waterproof grout to prevent water (from above) ever entering the stone in the first place.
Apart from the obvious disadvantage that a waterproof system will drain poorly as it relies purely on gradient drainage and evaporation to clear surface rain. Are there any other considerations or words of warning people can offer?
I am planning to do a worst case scenario "wet freezer test" on a spare piece of tile to try to gauge how concerned I should be about frost damage.