§912.22. Installation standards for manufactured and modular homes

           All manufactured and modular homes shall be installed to meet the following standards, unless otherwise specified in this Part:

           (1) Installation standards for the setup of new manufactured homes shall be in compliance with the manufacturer's installation instructions. Installation for the setup of new or used modular homes shall be in compliance with the International Residential Code enforced by the local authority having jurisdiction.

           (2) Installation standards for the setup of used manufactured homes shall be in compliance with the manufacturer's installation instructions, if available. In the absence of the manufacturer's installation instructions, used manufactured homes shall comply with the provisions of this Part.

           (3) All anchors, piers, and tie-down components used in the installation of manufactured homes shall be tested and meet the minimum industry standards. Installation of such anchors and components shall be in accordance with the manufacturer's instructions.

           (4) As to site preparation, the under-home grade, or ground, shall be cleaned of all vegetation and organic material, such as stumps, roots, etc., except grass not exceeding three inches in height. The area beneath and around the home shall be crowned, sloped or properly drained so that water will not flow or accumulate under the home. All grass and organic material shall be removed and the pier foundation placed on stable soil or compacted fill. When the soil compaction or soil-bearing capacity is not known, the local building authority in the locale may be consulted or a reading by the use of a pocket penetrometer may be obtained. The bottom of the footer or footers shall be placed on stable soil. The pier foundation shall be a minimum of three and one-half inches by sixteen inches by sixteen inches solid concrete pad or equivalent, precast or poured in place, or approved material by the regulatory agency. The regulatory agency, or its duly authorized representatives, shall cause products to be analyzed or tested to require that the pier foundation products have a deflection of not more than three-eighths inch under design load. Such testing may be conducted by an independent third party qualified and approved by the agency. Previous testing data submitted in other jurisdictions may be considered by the agency. Where the manufacturer's specifications have additional requirements other than the above, the more stringent shall apply. The landowner shall be responsible for proper site preparation in accordance with this Paragraph.

           (5) All manufactured homes shall be anchored with an approved anchor system. All auger systems shall be installed to a minimum depth of thirty inches, or two and one-half feet, in undisturbed or compacted soil. Piers are to be installed off center of the anchors so as not to interfere with the proper alignment of the strapping. Anchors may be installed in predrilled holes, provided the anchor penetrates a minimum of two feet into undisturbed soil beyond the predrilled hole. When the anchor manufacturer's installation instructions permit, the hole is then backfilled with soil compacted in layers not exceeding six inches. For manufactured homes produced after July 13, 1994, the installer shall refer to the manufacturer's setup manual for the ultimate load requirements for anchors at the different tie points on the manufactured home. For used manufactured homes when the manufacturer's setup manual is not available, all anchor points at side walls, shear walls, end walls, centerline, and other points as identified by the manufacturer, shall be certified for an ultimate load of four thousand seven hundred twenty-five pounds. Anchors are required one at each end of shear walls; one on each end of each I-beam; one frame tie at each vertical tie point; one in each end of each marriage wall, centerline; and on each ridge beam support post.

           (6) Frame tie ground anchors shall have approved stabilizing devices installed on the inside, in the direction of pull, with the top of the stabilizing plate driven flush with the soil unless otherwise specified by the manufacturer's guidelines.

           (7) Piers or load-bearing supports or devices shall be installed and constructed to evenly distribute the loads. Steel piers with mechanical adjustments shall be securely attached to the frame of all manufactured homes. Manufactured load-bearing supports or devices shall be listed and approved for the use intended, or piers shall be constructed as outlined in this Part. Concrete products shall comply with the minimum dimensional and structural requirements for load-bearing. Solid and cell concrete blocks shall be to the standard specification for load-bearing concrete masonry units, ASTM C-90, 1993 Edition. Poured concrete shall be a minimum of FCL = 2500 PSI. All plastic products shall be conditioned at ASTM D 618-61, reapproved 1990, standard practice for conditioning plastics and electrical insulating materials for testing. Plastics shall be tested to the ASTM D 790-92 standard test methods for flexural properties or unreinforced and reinforced plastics and electrical insulating materials, ASTM D 732-85 standard test method for shear strength or plastics by punch tool, and ASTM G 53-88 standard practice for operating light and water exposure apparatus for exposure of nonmetallic materials.

           (8)(a) In flood-prone areas, the foundation shall comply with the requirements set forth in the manual, Manufactured Home Installation In Flood Hazard Areas, published by the Federal Emergency Management Agency (FEMA). Nothing in this Paragraph shall be construed to prohibit state or local jurisdictions from adopting more stringent elevation or freeboard requirements than those contained in the FEMA manual, consistent with Subparagraph (b) of this Paragraph.

           (b) For all manufactured and modular home installations in this state, the state and political subdivisions may adopt laws, rules, ordinances, building codes, or other measures to regulate installations that include additional freeboard requirements beyond the minimum standards adopted by the National Flood Insurance Program, 42 U.S.C. 4011 et seq. in order to incentivize going above the minimum floodplain management standards. Freeboard requirements shall be uniformly applied based on the Base Flood Elevation established in the currently adopted Flood Insurance Rate Map for the jurisdiction and shall not vary based on alternative or superseded mapping sources.

           (c) All applications submitted to and permits issued by a jurisdiction's permit office shall include the Base Flood Elevation at the permitted site and the required finished floor elevation, including any applicable freeboard.

           (9) The marriage line on all multisectional homes shall be sealed with industry-approved materials at the ceiling line, the floor line, and the end walls to restrict any air infiltration into the home.

           Added by Acts 1997, No. 970, §1. Amended by Acts 2000, 1st Ex. Sess., No. 92, §1; Acts 2001, No. 500, §1; Acts 2001, No. 718, §2; Acts 2004, No. 419, §1, eff. July 1, 2004; Acts 2008, No. 217, §1, eff. August 15, 2008; Acts 2010, No. 1018, §1, eff. August 15, 2010; Acts 2017, No. 221, §1, eff. August 1, 2017; Acts 2025, No. 265, §1, eff. August 1, 2025.