Limestone is one of several natural stones that can be made into tiles, used for flooring, backsplashes and bathtub surrounds. This porous tile comes in a variety of colours, ranging from off white to pinkish, shades of grey and even a tint of blue. Because limestone is a natural substance, there are imperfections and colour variances in every tile. This is part of what provides its charm. Installing limestone requires heavy lifting and plenty of patience to be done correctly.
Ensure that the floor is clean of any dirt and debris. Apply a levelling compound to any places on the floor that are uneven with a putty knife, covering all joints between boards and damaged areas. Using a power sander, sand the floor to a smooth finish.
Lay the limestone tiles out on the floor to gauge their appearance. This is important because each tile is slightly different. Laying them out before installing them will ensure that no tiles clash with one another. Some tiles may have small holes or dips in them, but this is not a defect. These holes will be filled when you grout between the tiles.
Using a 10-millimeter notched trowel, apply a layer of white, rapid-set adhesive over the area for one tile. Do not use grey adhesive, as it may discolour the tiles from the underside. Place the limestone tile on the adhesive and shift it slightly to set it. Leave a gap of 6 millimetres before laying the next one. Continue laying the limestone tiles using this process until you have completed the room.
Apply a coat of natural surface hardener sealant. Pour it into a wide container for easier access. Brush the sealant on the limestone tiles with a 4-inch paintbrush. Any brush marks that remain after a few minutes should be removed by wiping over them with a white cotton microfiber cloth. Allow the sealant to dry for at least three hours before walking on it.
Fill the gaps between the limestone tiles with flexible grout. To do this, spread some grout on a squeegee and pull it across the tiles, allowing the grout to fill the gaps between the tiles and any small holes or dips in the tiles. Allow the grout to dry for six hours. A second application of grout is needed because the limestone tiles are typically 20 millimetres thick and a single application will not fill the gaps between the tiles. After the second application, allow the grout to dry for 24 hours.
Clean the limestone tiles thoroughly with a damp sponge to remove any dust or residue, and then dry them off with a towel. Apply a second coat of the natural surface hardener sealant and allow it to dry for 24 hours.
Apply a coat of natural surface wax to the limestone tiles. Allow the wax to harden for 10 minutes, then buff the tiles with a soft brush. Although only one coat of wax is required, additional coats will give added protection to the floor.