(1) Installation instructions provided with manufactured homes must be followed for installation. These instructions are designed to be applicable when certain aspects of the manufacturer's installation instructions are not explicit, not stipulated or need clarification, or when the manufacturer's instructions indicate that the requirement may be left to the authority having jurisdiction. The Federal Manufactured Home Construction and Safety Standards Program (24 C.F.R. 3280, 3282 and 3283) requires that all manufactured homes be provided with installation instructions covering foundation, anchoring, utility connections, and other items. Such installation instructions shall be utilized and followed for the installation of all new manufactured homes. Previously occupied manufactured homes and mobile homes which do not have manufacturer's installation instructions shall be installed according to requirements herein. The term mobile home shall be synonymous with the term manufactured home when used herein. Manufactured homes located within rental communities shall not be required to have poured concrete or permanent foundations.(2) Definitions: (a) Anchoring Equipment: Straps, cables, turnbuckles and chains, including tensioning devices, that are used with ties to secure a manufactured home to ground anchors;(b) Anchoring System: A combination of ties, anchoring equipment and ground anchors that will, when properly designed and installed, resist the overturning of the home or the moving of the home sideways by wind;(c) Footing: That part of the support system that sits directly on the ground at, below or partly below grade to support the piers;(d) Ground Anchor: A device at the manufactured home stand designed to transfer manufactured home anchoring loads to the ground;(e) Pier: That portion of the support system between the footing and the manufactured home, exclusive of caps and shims. Types of piers include, but are not limited to, the following:1. Manufactured steel stands;2. Manufactured concrete stands;4. Other approved or listed equivalent.(f) Radius Clips: Means or method to protect strapping from sharp edges during loading.(g) Site, Manufactured Home: A parcel of land designed and designated for the location of one manufactured home, its accessory buildings or structures, and accessory equipment for exclusive use of the home;(h) Stabilizing Devices: All components of the anchoring and support systems such as piers, footings, ties, anchoring equipment, ground anchors, or any other materials and methods of construction which support and secure the manufactured home to the ground;(i) Stand, Manufactured Home: That area of a manufactured home site which has been reserved for placement of a manufactured home;(j) Support System: A combination of footings, piers, caps and shims that will, when properly installed, support the manufactured home;(k) Tie: Strap, cable or securing device used to connect the manufactured home to ground anchors; (l) Vertical Tie: A tie intended to resist the uplifting and overturning forces.(3) Foundation Systems for New Manufactured Homes.(a) A manufactured home foundation system is one constructed in accordance with the foundation system included in the manufacturer's installation instructions.(b) The manufacturer or homeowner shall be permitted to design for unusual installation not provided for in these regulations or in the manufacturer's standard installation directions provided the design is approved in writing by a licensed professional engineer or architect and a copy provided to the Manufactured Housing Section of the Safety Fire Division.(c) The manufacturer's instructions include a typical foundation system designed by a registered professional engineer or architect to support the anticipated loads specified in the manufacturer's installation instructions for the design zone (including climate) of installation, and shall be deemed to meet the requirements of these regulations. These instructions shall be provided to the homeowner as required by Rule 120-3-7-.18.(4) Foundation Systems for Previously Owned Manufactured Homes.(a) Foundation systems for previously owned manufactured homes shall be according to requirements contained herein. Previously occupied manufactured homes can be installed according to manufacturer's installation instructions if available.(b) Subparagraph (7) contains information for the design of manufactured home foundation systems which meet the minimum criteria established in this regulation.(c) The manufacturer or homeowner shall be permitted to design for an unusual installation not provided for in the manufacturer's installation instructions, or these Regulations, provided that the design is approved in writing by a licensed professional engineer or architect and a copy sent to the Manufactured Housing Section of the Safety Fire Division and the manufacturer.(5) Stabilizing Devices and Design. (a) Each new or previously owned manufactured home being installed on a manufactured home stand shall have stabilizing devices and shall be installed on a foundation constructed in accordance with the manufacturer's installation instructions for new manufactured homes or standards included within these regulations for previously occupied manufactured homes.(b) Stabilizing devices not provided with the manufactured home shall be listed or labeled to meet or exceed the design and capacity requirements of the manufactured home manufacturer's installation instructions and these regulations.(6) Anchoring. (a) Each manufactured ground anchor shall be listed and installed in accordance with the terms of its listing and the anchor manufacturer's instructions and shall include means of attachment of ties meeting the requirements of the manufacturer's installation instructions for new manufactured homes or subparagraph (6)(h) of these regulations for previously occupied manufactured homes.(b) Ground anchor manufacturer's installation instructions shall include tensioning adjustments which may be needed to prevent damage to the manufactured home.(c) Each ground anchor shall have the manufacturer's identification and listed model identification number marked thereon so that the number is visible after installation.(d) Instructions shall accompany each listed ground anchor specifying the types of soil for which the anchor is suitable under the requirements of Section E.(e) Ground anchors, including means for attaching ties, shall be located to effectively match the anchoring system instructions provided by the manufactured home manufacturer, or for previously occupied manufactured homes, in accordance with the requirements of this section.(f) Concrete slabs or footings: If concrete slabs or continuous footings are used in lieu of ground anchors to transfer the anchoring loads to the ground, steel rods cast in concrete, or deadman, or concrete anchors shall be required and shall be capable of resisting loads as specified in subparagraph 6)(g)1.(g) Anchors: 1. Capacity of Anchors: Each approved single head ground anchor, when installed, shall be capable of resisting an allowable working load at least equal to 3,150 pounds, plus a 50% overload (4,725 pounds), without failure when pulled in the direction of the tie. Anchors designed for connection of multiple ties shall be capable of resisting the combined working load and overload as outlined in this Section. Anchor type and size to be determined by soil probe test. Probe test must be performed within 2 feet of each corner of unit.2. Anchoring Equipment: Anchoring equipment shall be capable of resisting an allowable working load equal to or exceeding 3,150 pounds and shall be capable of withstanding a 50% overload (4,725 pounds) without failure of either the anchoring equipment or the attached point on the manufactured home. When the stabilizing system is designed by a qualified registered professional engineer or architect, alternative working loads may be used provided the anchoring equipment is capable of withstanding a 50% overload. All anchoring equipment shall be listed or labeled as being capable of meeting all the requirements of this section.3. Selection of Helical Anchors: Anchor selection shall be based on a determination of the soil class at the depth the anchor helical plate will be installed.4. Other Anchoring Devices: Other anchoring devices meeting requirements of this section shall be permitted if acceptable to the Manufactured Housing Section of the Safety Fire Division.5. Depth of Anchors: All anchors shall be installed to the full depth shown in the anchor manufacturer's installation instructions.6. Anchors installed in line with the pull must be of sufficient additional length to compensate for loss of depth.7. Anchors are to be placed within 2 feet of each end of each section in Zone I and II. In addition: (i) Zone I anchors must be placed 8 feet on center maximum along the length of both exterior sidewalls.(ii) Zone II anchors must be placed 6 feet on center maximum along the length of both exterior sidewalls.(iii) Both Zone I and II must have two longitudinal ties and anchors at each end of each section attached to the main "I"Beams. For pier heights exceeding 49 inches, anchors must be strapped to both "I"Beams. NOTE: Zone II homes produced since July 1994 must have vertical ties at each diagonal tie location.8. Anchor length and/or type must be determined by probe testing all four corners, within two feet of corners. Results may be averaged and used to determine anchors based on the anchor manufacturer's installation and/or user manual requirements.9. Approved alternate systems of anchoring may be used when proof that the manufacturer has approved such systems is provided.(h) Ties: 1. Strappings or other approved methods or materials shall be used for ties. All ties shall be fastened to ground anchors and drawn tight with turnbuckles or other adjustable tensioning devices or devices supplied with the ground anchor. Strapping must be protected at sharp edges with radius clips. NOTE: Splicing for vertical ties only; overlap strap 12 inches minimum with two clips (one facing each way), double crimp each clip with proper crimping tool.2. Tie materials shall be capable of resisting an allowable working load of 3,150 pounds and shall withstand a 50% overload (4,725 pounds total). Ties shall comply with 24 CFR 3280.306.3. Ties shall connect the ground anchor to the top portion of the main structural steel frame (I-beam or other shape) which runs lengthwise under the manufactured home. Ties shall not connect to steel outrigger beams which fasten to and intersect the main structural frame unless specifically stated in the manufacturer's installation instructions.4. Number of Ties: The minimum number of ties per side for various lengths of manufactured homes in Wind Zone I and Wind Zone II shall be in accordance with subparagraph (g).5. Location of Ties: When continuous straps are provided as vertical ties, such ties shall be positioned at rafters and studs. Where a vertical tie and diagonal tie are located at the same place, both ties shall be permitted to be connected to a single ground anchor, provided that either the anchor used is capable of carrying both loadings, or that the load capacity of the total number of anchors used is equal to 3,150 pounds working load plus 50% overload (4,725 pounds) times the number of ties specified in subparagraph (g).6. Shearwall and/or other provided ties and/or brackets must be anchored with same anchor as probe test results required for remainder of home.7. When longitudinal brackets are provided, strapping material and anchors as described in Subparagraph (g) must be installed.8. Special Ties: Clerestory roofs and add-on sections of expandable manufactured homes shall have provisions for vertical ties at the exposed ends. When not originally installed by manufacturer, over-the-roof or vertical ties shall not be required for manufactured homes constructed with "A"Line and shingle roofs.9. Alternate Method Using Cable Ties: Connection of the cable frame tie to the manufactured home I beam or equivalent main structural frame member may be by a 5/8 drop-forged closed eye bolt through a hole drilled in the center of the I-beam web or other approved methods. The web shall be reinforced if necessary to maintain designed I-beam strength. Cable ends shall be secured with at least three (3) U bolt-type cable clamps with the U portion of the clamp installed on the short (dead) end of the cable to assure strength equal to that required by Section E(8).10. Tensioning Device Design: Tensioning devices such as turnbuckles or yoke-type fasteners shall be ended with a clevis or forged or welded eyes.11. Permanency of Connections: Anchoring equipment shall be designed and installed to prevent self-disconnection, lateral deflection or failure.(i) Resistance to Weather Deterioration: All portions of the anchor which are exposed to weathering shall have a resistance to weather deterioration. The remainder of the anchoring equipment shall have resistance at least equivalent to that provided by a coating of zinc on steel of not less than 0.30 ounces per square foot on each side of the surface coated, as determined by ASTM Standard Methods of Test for Weight of Coating on Zinc-Coated (Galvanized) Iron or Steel Articles (ASTM A90-81).(7) Foundation Standards.(a) Unless the entire support system is designed by a professional engineer or architect, the support system shall be designed in accordance with this standard.(b) Footings shall be sized to support the loads shown in the manufacturer's instructions. Where no manufacturer's instructions are available, subparagraph (7) shall apply.(c) All grass and organic material shall be removed from the pier foundation location(s), and the pier foundation placed on stable soil at a depth sufficient to protect the footings from the effects of frost heave. For purpose of the installation of a manufactured or mobile home in the State of Georgia, all footers must be protected from the effects of frost heave. When properly designed by a registered professional engineer, a "floating slab"system may be used above the frost line. The design shall accommodate the anchorage requirements identified within this regulation and/or the manufacturer's installation instructions.(d) The pier foundation shall be a 16"x16"x4"solid concrete pad, precast or poured in place, or other approved methods/materials. Where poured concrete foundations are required by local authority for multiple section homes, the footing size shall be 24"x24"x6"filled with poured concrete, or other approved materials/methods. Concrete in footings shall have an ultimate compressive strength of not less than 2500 psi at 28 days. Footer size may vary on piers used with alternate anchoring systems, when installed per system manufacturer's instructions, and marriage wall piers as required by manufacturer's instructions. 1. For the purpose of installing a manufactured/mobile home in the State of Georgia . The bases of concrete or other pad types are to be placed at or below the frost line. Other types of footings such as pans, domes, or open pans are to be placed with the topmost point that serves as the base set at or below the frost line, so as to avoid the effects of frost heave. The frost line in the State of Georgia is determined to be:(i) 4"for the following counties and all counties to the north of these counties: Troup, Meriwether, Pike, Lamar, Monroe, Jones, Baldwin, Washington, Jefferson, and Burke;(ii) 2"for the following counties and all counties to the south of these counties: Harris, Talbot, Upson, Crawford, Bibb, Twiggs, Wilkinson, Johnson, Emanuel, Jenkins, and Screven.(e) Footings or pier foundations (unless approved by a registered professional engineer) when required, shall be placed level on firm undisturbed soil or on controlled fill which is free of grass or organic materials to minimum load-bearing capacity of 1000 psf.(f) Piers and Spacing: 1. Piers or load-bearing supports or devices shall be designed and constructed to evenly distribute the loads.2. Double piers are to be placed within 2 feet of each end of each main I-beam, and remaining piers spaced no more than 6 feet on center for the remaining length of each main I-beam.3. Piers are to be placed on each side of exterior wall opening 4 feet wide or greater (footers at these openings may be 4"x 8"x 16", or equivalent product).4. Piers shall be placed on each side of exterior door opening (footers may be 4"x 8"x 16", or equivalent). Openings for endwalls with full headers or cross members do not require piers and footings for the openings.5. The marriage line of multiple section manufactured homes shall be supported by piers spaced no more than 20 feet apart and shall have piers located within 2 feet of each end of the home, under the marriage line, in conjunction with these piers, piers must be placed at each end of openings 6 feet wide or more. Marriage line piers must support both marriage line floor rails. Footers must be a minimum of 16"x 16"x 4"or equivalent.6. Load-bearing supports or devices shall be listed or approved and shall be designed by a registered professional engineer or architect and shall be approved for the use intended or piers shall be constructed as follows: (i) Piers less than 40 inches in height shall be constructed of open or closed cell, 8 inch by 16 inch, concrete blocks with open cells vertically placed upon the footing. The pier shall be covered with a 2 inch by 16 inch by 8 inch wood or nominal concrete plate.(ii) Piers between 40 inches and 80 inches in height and all corner piers shall be double blocked with blocks interlocked and capped with a 4 inch by 16 inch by 8 inch solid concrete block or equivalent or 2 inch by 8 inch nominal pressure treated wood or hardwood covering the cell area.(iii) Piers over 80 inches in height must be designed and approved by a registered professional engineer.(iv) Steel piers, or other approved piers, when used, shall be in compliance with subparagraph (6)(i) after fabrication to provide corrosion protection.(v) Load bearing and non-load bearing walls constructed on site shall be constructed of concrete, masonry, pressure treated wood or any other approved material or system. Minimum thickness shall be that required to resist lateral pressure from adjacent earth and support design loads as determined by acceptable engineering practice.(vi) Plates, Shims and Wedges: Nominal 2"x 8"x 16"pressure treated wood, hardwood, 4"concrete caps or the equivalent, shall be placed on top of the pier for the purpose of a top plate. Plate must cover cell area in both single or double stack blocks. Any gap between the top plate and the I-beam frame may be filled with pressure treated wood or hardwood, nominal minimum size of 8"x 4"x 1", fitted and driven tight. Wedges shall not occupy more than one inch of vertical space and shall be at least 3"wide and 6"long, fitted from both sides and driven tight together between the I-beam and plate or shim. Wood and wedges may occupy no more than 4"of the space between the pier and main frame.(8) Placement of Manufactured Homes.(a) Clearance Under Homes: A minimum clearance of 12 inches shall be maintained beneath the lowest member of the main frame (I-beam or channel-beam) in the area of utility connections. No more than 25% of the underside of the main frame of the home shall be less than 12 inches above grade.(b) Elevated Manufactured Homes: When the manufactured home is installed on a basement or split entry type foundation over a habitable lower-level area, the foundation system shall be designed by a registered professional engineer or architect.(9) Ventilation of Manufactured Homes.(a) Ventilation of Underfloor Areas:1. Provisions shall be made to minimize condensation in underfloor areas through ventilation openings or other suitable means. A 6 mill poly vapor barrier, or equivalent, must be placed on the ground area in the crawl space. A minimum of 90 percent of the ground area must be covered, not to include area under footers.2. If combustion air for heat-producing appliance(s) is taken from within the underfloor areas, ventilation shall be adequate to assure proper operation of the appliance(s). This requirement shall take precedence over the provisions of subparagraph (9)(a)1. Note: This is in addition to the crawl space requirement.3. A minimum of four ventilation openings totaling no less than four square feet of net free vent area, must be provided. One shall be placed at or near each corner as high as practicable. Crawl space ventilation net free requirement shall be calculated as follows: a=A/1500 where:
A=the area of the crawl space, square foot a=the total net free vent space.
If the manufacturer's installation instructions require additional vents or openings, the manufacturer's instructions shall apply.
4. Openings shall provide cross ventilation on at least two opposite sides. The openings shall be covered with corrosion resistant wire mesh not less than 1/8 inches, and not more than 1/2 inches in any dimension or with screened louvered openings to retard entry of dry vegetation, waste materials, or rodents. As an option to individual vents, ventilation can be provided by means of vinyl material which has openings for air ventilation as provided in the minimum requirements above.(b) Intake air for ventilation purposes shall not be drawn from underfloor spaces of the home.(c) Moisture producing devices, such as dryers, shall be vented to the atmosphere in such a manner to insure that moisture laden air is carried beyond the perimeter of the home.(d) Skirting: Skirting, if used, shall be installed in accordance with the manufacturer's installation instructions. It shall be secured, as necessary, to assure stability, to minimize vibrations, to minimize susceptibility to wind damage, and to compensate for possible frost heave. Access opening(s) not less than 18 inches in any dimension and not less than 3 square feet in area shall be provided to allow for access and inspection of the home. Such access panel(s) or door(s) shall not be fastened in a manner requiring the use of a special tool to remove or open same. On-site fabrication of skirting shall meet the venting requirements of subparagraph (9)(a).(10) Maintenance of Anchoring Systems: The homeowner shall be advised that tie tension should be checked and adjusted when necessary.(11) Plumbing. (a) Each manufactured home site shall be provided with a water supply and sewer located and arranged to permit attachment to the manufactured home in a workmanlike manner.(b) When the entire system has been completed, install permanent drain line supports at 4' on center.(c) Proper slopes and connector sizes: Drain lines must slope at least 1/4"fall per foot of run. EXCEPTION: 1/8"fall per foot is allowed when a clean out is installed at the upper end of the run. Connect the main drain line to the site sewer hookup. Plumbing drain lines must be supported so as to slope at least 1/4"fall per foot of run or 1/8"fall per foot of run when full-size clean out is located in upper end of line.(12) Manufactured Home Electrical Connections.(a) When a manufactured home consists of two or more sections, all electrical connections from one section to another shall be installed in accordance with the manufacturer's installation requirements. In the absence of manufacturer's instructions, electrical connections shall be made in accordance with the National Electrical Code.(b) Manufactured homes may have the service equipment mounted on or in the unit provided such units comply with all of the following conditions:1. Installed on a private or owner's lot;2. Permanent utility connections provided;3. Located on a properly constructed foundation;4. Unit is properly anchored and tied down;5. Unit is constructed in accordance with HUD Construction Standards;6. Service equipment complies with Article 230 and 250 of the Georgia (National) Electrical Code.(c) All manufactured home utility services shall be connected to the supply sources with only approved materials.(d) When a manufactured home is designed to have a meter mounted on home, the electrical service supply is allowed to be installed directly on the home subject to compliance with subparagraph (12)(b), above.(e) Temporary Electrical Service: The authority having jurisdiction shall allow for temporary electrical service for the installation of the manufactured home when the home consists of two or more sections.(13) Retail Display. (a) All manufactured homes and mobile homes displayed for retail sales on dealership or retailer lots shall be stabilized to such a degree as to not allow damage to occur while the home is on display. 1. Piers for multi-section homes shall consist of a minimum of twelve (12) piers and shall be located one under each I-beam in the front of each axle area and at each end of the manufactured home.2. Piers for single section homes shall consist of a minimum of six (6) piers one located under each I-beam at each end of the home and in front of the axle area.(14) Sites Prone to Flooding. Special elevations and anchoring techniques are required when locating a home in an area prone to flooding. Consult an engineer and the local building official to make sure that the design and construction of the foundation system conform to applicable federal, state, and local codes and regulations. The Federal Emergency Management Agency (FEMA) publication FEMA 85, "Manufactured Home Installation in Flood Hazard Areas,"contains design and anchoring systems that will allow the foundation system to resist flood forces. This publication is available from FEMA, Washington, DC 20472. Further information may be obtained from the Manufactured Housing Section of the Office of the Insurance and Safety Fire Commissioner. In areas where a community meets the eligibility requirements for the National Flood Insurance Program, the local jurisdiction having authority shall have the authority to change, delete or modify these regulations in order to comply with the National Flood Insurance Program created by the National Flood Insurance Act of 1968, as amended and/or Rules and Regulations of FEMA addressing the installation of manufactured and mobile homes in areas subject to flooding.(15) Additional Installation Requirements for Previously Owned Multi-Section Manufactured Homes and Mobile Homes. The floor sections, roof sections and wall sections are to be fitted together tightly. Connections must be sufficiently sealed to prevent air infiltration. Connection of multi-section manufactured homes and mobile homes (two or more sections), when manufacturer's installation instructions are not available shall be as follows:(a) Floor Connection: All floors of multi-section manufactured homes and mobile homes shall be securely fastened together with 5/16 inch lags 4 inches long and 16 inches on center entire length of home. All sections shall be leveled and aligned making sure the floors are even on top.(b) Roof and Ridge Beams: All roof and ridge beams of multi-section manufactured homes and mobile homes shall be securely fastened together. 1. Metal roof connections to be minimum 30 gauge galvanized metal, 12 inches wide, fastened with #8 x 1 1/4 screws minimum, at 4"on center around perimeter of the entire length of the cap.2. Wood/shingle roofs fastened with one of the following options:(i) Minimum 30 gauge galvanized metal, 10 inches wide by length of roof. Fastened with minimum 1 1/2"fasteners at 4 inches on center along entire perimeter of the cap.(ii) Minimum 5/16 inch by 6 inch lag screws 16 inches on center, entire length of roof.(iii) 1 1/2 inch by 12 inch 26 gauge galvanized metal straps placed within 2 feet of each end and 8 feet on center entire length of units, fastened with # 8 x 1 1/2 inch screws, 5 each side of ridge joint.(c) End Walls: End walls of multi-section manufactured homes and mobile homes shall be securely fastened together. 1. Minimum #8 screws 8 inches on center entire height of end walls, with minimum of 1 inch penetration into the receiving member. If toe screw method is used, must have 1 1/2 inch penetration.2. 1/4 inch lag screws 24 inches on center with minimum 1 1/2"penetration into receiving member.3. 1 1/2"galvanized strapping placed 12 inches on center, entire height of stud, fastened with #10 nails minimum 2 each end of strap.4. Siding and trim pieces are to be installed at the connection of the sections.(d) Roof Covering: The joints at the ridge of the roof shall be secured and weather tight.(e) Plumbing drain lines must be supported off the ground. Unless specified in other sections of this Rule, all lines under the manufactured home shall be supported every 4' on center.(f) Crossover, heating, and other ducts: Heating and duct work is to be connected for proper heating/cooling operation. 1. Securely connect each end of the crossover duct underneath each section to the dropout connection;2. Wrap/cover all seams and joints with approved UL181 tape or equivalent;3. Wrap or cover exposed metal with insulation to reduce heat loss;4. Strap and support crossover duct 4 feet on center minimum. Duct must be supported off the ground.(16) Miscellaneous. (a) Where the means of egress from a manufactured home is not substantially level, such differences in elevation shall be negotiated by stairs or ramps. (Not applicable to egress windows.)(b) Auxiliary Structures: All auxiliary structures (such as porches, decks, awning, cabanas, stairs, etc., unless provided and approved by the manufacturer) shall be entirely self-supporting, unless designed and approved by a professional engineer or registered architect. All such structures shall be constructed in accordance with the Georgia State Building Codes or local authority having jurisdiction.Ga. Comp. R. & Regs. R. 120-3-7-.18
O.C.G.A. Secs. 8-2-130, 8-2-133, 8-2-160, 8-2-166, 25-2-1, 25-2-4, 33-2-9, 50-13-21.
Original Rule entitled "Forms"adopted. F. Oct. 7, 1992; eff. Jan. 1, 1993, as specified by the Agency.Amended: F. July 22, 1996; eff. August 11, 1996.Repealed: New Rule of same title adopted. F. Aug. 6, 1998; eff. Aug. 26, 1998.Repealed: New Rule entitled "Installation Instructions"adopted. F. Nov. 30, 2004; eff. Dec. 20, 2004.