Another thing wth tiles depending how close you live to the sea , depends on the securing of the tiles . I built 600 metres off the beach of the Indian Ocean so just about every 3rd tile had to be screwed down .If had of had wood beams a nail would of done the job. However I preferred to be ant free. The snakes were quite welcome , you always knew they were on the move when the frogs were chirping away ,no frogs and the snakes had probably eaten them so was best to keep looking over your shoulder., and watch where you put you feet until I got the lawn cut. JS