Foundations and footings for concrete masonry units (CMU) walls.
(1) Footings for load bearing CMU walls must be continuous concrete having a minimum twelve width-by-ten inch thickness, placed a minimum eighteen inches below the finished grade, and reinforced with a minimum of two No. 4 continuous rebar.
(2) Foundations must be one of the following:
(a) Concrete reinforced vertically and horizontally with No. 4 rebar at twenty-four inches on center; or
(b) CMU reinforced vertically and horizontally with No. 4 rebar and having all cells below finished grade fully grouted.
(3) Vertical reinforcement must be spaced at four feet on center, within twelve inches of each corner, extend at least twenty inches up into the CMU wall, and extend at least six inches into the footing with an additional six inches bent at ninety degrees and tied to the horizontal footing rebar.
(4) Foundations must be six inches in width or the width of the CMU wall, whichever is greater.
[Statutory Authority: RCW 70.114A.081
. WSR 99-03-065, § 246-359-410, filed 1/18/99, effective 2/18/99.]