Slope Block Features:   TEL .(805) 376 9924 FAX .(805) 499 0864 280 ASTA AVE. NEWBURY PARK CALIFORNIA 91320 U.S.A. E-MAIL slopeblock1@gmail.com Natural Gravity Walls Permits are usually NOT required for retaining walls at about 3 ft. in height. In most cases slopeblock walls about 6 ft. in height DO NOT require a concrete footing. Use Slope Block Installation Guide for footingless walls. In firm soil for walls above 6 ft. height with a minimum 2ft. wide concrete footing and a minimum tilt of 30 degrees, Slope Block is considered an erosion system. Structural calculations, based on I.C.B.O. (International Conference of Building Officials) ICC Report No. ER-5863, are available. Click report for adobe acrobat .pdf file.   contact - products - projects - features - home SLOPE BLOCK TEL .(805) 376 9924 FAX .(805) 499 0864 Home Page ..www.slopeblock.com  280 ASTA AVE. NEWBURY PARK CALIFORNIA 91320 e-mail slopeblock1@gmail.com Copyright � 1999 & 2000. Slope Block, Inc.. All rights reserved.