This detail shows 2 cm (3/4 in.) thick dimension stone on an unbonded mortar bed over a concrete substrate. The mortar setting bed is separated from the concrete with a cleavage membrane to allow the stone assembly to move independent of the structure. The stone is typically fresh-set (i.e. the mortar bed is still workable) and adhered to the mortar with a cementitious bond coat; alternatively, the mortar bed may be allowed to cure before adhering the stone.
Optional compatible waterproof membrane (not shown) may be applied over the mortar bed if it is cured. The mortar bed is reinforced with a 2″ x 2″ galvanized wire mesh. Expansion joints in the floor assembly must be provided at locations shown by the design professional. This detail is based on Natural Stone Institute’s exterior stone paving detail, Full Mortar Bed with Membrane and Expansion Joint. Details that show different or modified concepts or methods can be of equal validity and should not be excluded from consideration. This detail shall not be used for construction without the approval and signature of a licensed design professional. The person using this detail shall be responsible for its complete design and proper application.