Required Piers and Anchorages

Required Piers and Anchorages A. All used Factory-Built homes are required to have diagonal and longitudinal anchors with tie downs to restrict the unit from being pushed from the main support piers. These diagonal anchors and tie down straps also restrict overturning of the structure. Additional over-the-top tie downs or vertical side wall tie downs to restrict overturning are required for some Factory-Built home installations based on the Wind Zone designation of the home. When a used Factory-Built home is relocated (secondary move) all of the original or existing diagonal, longitudinal and vertical tie downs for the wind zone designation of the home must be reinstalled, however, no anchors removed from the previous installation site shall be used at the new installation site. The installer is required to obtain photographs of all the tie downs and existing brackets present on the home before the home was moved to validate the set-up of the home at the new location. B. Piers or load bearing support or devices shall be designed and constructed to evenly distribute the loads. The maximum pier loads are listed in Table III and Table IV. Piers shall be securely contacting each I-beam of the Factory-Built home and shall extend at least six (6) inches from the centerline of each I-beam. Other types of load bearing supports or devices shall be listed or approved for the use intended. TABLE III – MAXIMUM PIER LOAD IN POUNDS Number of Concrete Blocks Soil Bearing Value Maximum Allowable Load 1,000 lbs./square foot 4,800 lbs. 2,000 lbs./square foot & greater 9,600 lbs. * ABS Pad types include the following: 13 ¼” x 26 ¼” Pad 2.395 square feet ID#4148 4 or 20” x 20” Pad 2.777 square feet ID#1055 7 TABLE IV - MAXIMUM PIER LOAD Type ABS Pad Configuration ABS Pad Area (in square inches) Soil Bearing Capacity PSF (in pounds) Remarks 1-16 x 16 w/1 or w/2 CMUs Max: 5340 # 1-18.5 x 18.5 w/1 CMU Max: 5600 # 1-18.5 x 18.5 w/2 CMUs Max: 7125 # 2-13.13 x 26.13 w/1 CMU Max: 6400 # 1-18.5 x 18.5 w/1 CMU ID# SPA 264 1 1 Max: 7125 # 1-20 x 20 w/1 CMU Max: 5600 # 1-20 x 20 w/2 CMUs Max: 8333 # All pad sizes shown are nominal dimensions and may vary up to 1/8 inch. C. Pier foundations shall be installed directly under each I-beam of the Factory-Built home. If the Factory-Built home installation instructions are not available for a used home, piers for single section homes are to be placed under each longitudinal I-beam not to exceed 8 ft. on center spacing for homes that are 14 ft. wide or less when using a minimum soil bearing capacity of 2,000 psf. End piers shall be placed no more than two (2) feet and no less than one (1) foot from the end of each I-beam. D. For used homes, having no manufacturers installation instructions, of widths over 14 ft, piers shall be placed under each I-beam no further apart than 6 ft. on centers, when using a minimum soil bearing capacity of 2,000 psf. End piers shall be placed no more than two (2) feet and no less than one (1) foot from the end of each I-beam.