Clay tile roof should have how much overlap? a. 6" b. 3" c. 10" d. 12 What is the heaviest roof material per sq. ft.? a. Slate/concrete tile b. Asphalt c. Fiberglass d. Tar & gravel with ballast Wood shingle/shakes should be spaced how far apart? a. 3/8" b. 5/8" c. 1/2" d. 3/4" Flat roofs - what is the most common cause of leaking? a. Seams b. Ponding c. Parapet walls d. Gutters What does water ponding cause? a. Shorten life expectancy b. Promotes fungi & moss growth c. Allows seepage d. All of the above Flat roofs- what is the cause of blisters? a. Rotted underlayment b. Poor grade of shing