First of all, spray polyurethane is applied to the concrete surface of the open terrace, which is cleaned from dust, moisture and loose materials. Then, concrete screed of desired thickness can be applied on the spray polyurethane. If the applied area is not a frequently used area, gravel can be laid. Or ultraviolet protective paint can be applied. Since it is the last layer in the closed roof application, after all dust and moisture have been removed from the floor, spray polyurethane is applied and so it can be left.