Housing Familiar dwg file. Layout plan, stair plan, construction plan, section plan and elevation design DRAIN PIPE TO HAVE a minimum slope of 1% in diameter from 4 "and larger . Type cimentación.- Foundation superficial. Foundations and footings calendar . Stratum support cimentación.- Mix poorly graded gravel in a sandy matrix, moderately compact. (GP) .. Parameter design for the foundation: - Depth cimentación.- Minimum Depth = 1.2m.- permissible pressure = 1.5 kg / cm2.- Safety Factor = 3.0- Court to limit angular distortion of the order of 1/300