# 3285.304 Pier configuration.
(a) *Concrete blocks.* Installation instructions for concrete block piers must be developed in accordance with the following provisions and must be consistent with Figures A and B to § 3285.306.
(1) Load-bearing (not decorative) concrete blocks must have nominal dimensions of at least 8 inches × 8 inches × 16 inches;
(2) The concrete blocks must be stacked with their hollow cells aligned vertically; and
(3) When piers are constructed of blocks stacked side-by-side, each layer must be at right angles to the preceding one, as shown in Figure B to § 3285.306.
(b) *Caps.* (1) Structural loads must be evenly distributed across capped-hollow block piers, as shown in Figures A and B to § 3285.306.
(2) Caps must be solid concrete or masonry at least 4 inches in nominal thickness, or hardboard lumber at least 2 inches nominal in thickness; or be corrosion-protected minimum one-half inch thick steel; or be of other listed materials.
(3) All caps must be of the same length and width as the piers on which they rest.
(4) When split caps are used on double-stacked blocks, the caps must be installed with the long dimension across the joint in the blocks below.
(c) *Gaps.* Any gaps that occur during installation between the bottom of the main chassis beam and foundation support system must be filled by:
(1) Nominal 4 inch × 6 inch × 1 inch shims to level the home and fill any gaps between the base of the main chassis beam and the top of the pier cap;
(2) Shims must be used in pairs, as shown in Figures A and B to § 3285.306, and must be driven in tightly so that they do not occupy more than one inch of vertical height; and
(3) Hardwood plates no thicker than 2 inches nominal in thickness or 2 inch or 4 inch nominal concrete block must be used to fill in any remaining vertical gaps.
(d) *Manufactured pier heights.* Manufactured pier heights must be selected so that the adjustable risers do not extend more than 2 inches when finally positioned.