Section Inst 603.03 - Design Requirements Including Load-Bearing Capacity(a) The load a pier can carry shall depend on the house, roof live load, spacing of the piers and the way piers are used to support the house.(b) Pier concrete blocks shall be stacked with their hollow cells aligned vertically.(c) Piers constructed of blocks stacked side by side shall be at right angles to the preceding course.(d) Piers shall be: (1) Concrete blocks which have a nominal dimension of at least 8 in. x 8 in. x 16 in.; or(2) Adjustable metal or concrete piers.(e) Manufactured adjustable metal piers shall be labeled for load capacity.(f) Caps shall be used to cap the hollow concrete blocks. All caps shall be of the same length and width as the rest of the piers on which they rest. The caps shall be of solid masonry of at least 4 inches thickness or wood of at least 2 inches of nominal thickness or 1/2 inchsteel on piers of less than 36 inches height.(g) Piers less than 36 inches high may be constructed of single, open and closed cell concrete blocks.(h) Piers between 36 inches and 67 inches high and all corner piers over 3 blocks high shall be constructed out of double interlocking blocks.(i) Piers over 67 inches high shall be designed by a licensed New Hampshire professional engineer or architect.(j) Mortar shall not berequired for concrete block piers, unless required by the manufacturer installation instructions or design.(k) No caps shall be needed for piers using solid blocks.N.H. Admin. Code § Inst 603.03
#8494, eff 12-24-05; ss by #10155, eff 4-14-12