fig6 and 10 the length of the front and rear blade extensions can be fabricated in any desired length in the system of the preferred embodiment three blade extension brackets having lengths of 6 12 and 18 inches are provided blade extension bracket 48 also includes a horizontally oriented strut 64 which extends between the end portions of blade extensions 60 and 62 to maintain a predetermined fixed spacing therebetween angled support struts 66 and 68 are coupled respectively to the outer end of front blade extension 60 and rear blade extension 62 and to the vertically oriented members of blade extension bracket 48 if desired vibrators may be coupled to the blade extension bracket referring now to fig1 and 17 a vertically and horizontally adjustable blade extension bracket 70 will be described a bracket of this type is particularly desirable when it is necessary to form a step or sidewalk adjacent to the roadbed or warehouse flooring which is being formed by the remainder of the screed the adjustable blade extension bracket 70 is coupled to the parallel oriented vertically extending side members 72 and 74 of end bracket 12 bracket 70 can be divided generally into a telescopically adjustable first section 76 which permits adjustment of the lateral extension of section 76 with respect to end bracket 12 a second vertically adjustable section 78 permits the entire unit to be adjustably secured to side members 72 and 74 of end bracket 12 section 78 includes a pair of horizontally oriented channel members 80 and 82 which are dimensioned to permit the two telescopically adjustable legs of section 76 to be readily laterally translatable within the interior of sections 80 and 82 securing means in the form of an adjustable bolt such as bolt 84 are provided in.