By ANSI Standard Specification A137.1 Metropolitan Ceramicsâ unglazed tile is classified as quarry tile, however, the exceptional technical characteristics noted enable them to be used in virtually any application suitable for ceramic tile. Metropolitan Ceramicsâ unglazed tile meets both the ASTM standards, the ANSI
Thickness is rated differently, depending on the material used. A thicker gutter system will be sturdier, more durable, and more expensive. Aluminum systems range from .019 to .032 inches in thickness. Copper is usually rated in weight, with a heavier weight indicating greater thickness. It is common to see 16-ounce and 20-ounce options for copper systems.
Currently there is no standard in the roof drainage industry but these concepts are based on handed down experience. 1  Outlet Sizing and Spacing Your gutter system will perform its best when a proper outlet size is chosen to drain a given roof area. Downspout sizes must not exceed the bottom width of the gutter. furthermore, the standard norm for gutters among many in the rain carrying industry is to allow 1 square inch of outlet opening in the gutter for every 100 square feet of roof area being drained.