SPS 321.40(2)(a)
(a) Except as provided in par.
(b), the installation of a manufactured home produced before April 1, 2007 shall be installed in conformance with the requirements in effect at the time the manufactured home was produced.
SPS 321.40(2)(b)
(b) The installation of a manufactured home produced before April 1, 2007 to be installed on piers shall conform to at least all of the following requirements:
SPS 321.40(2)(b)1.
1. No footing may be placed upon unprepared fill material, topsoil, alluvial soil or mud. All organic matter shall be removed from the area that will be beneath any footing.
SPS 321.40(2)(b)2.
2. The soil bearing capacity shall be determined through test by a pocket penetrometer or other means of analysis. If the soil bearing capacity under each intended pier location is less than 2000 pounds per square foot, piers shall be located in accordance with the manufacturer's instructions.
SPS 321.40(2)(b)3.
3. The home site shall be graded to permit water to drain from under the home and away from the home for a minimum of 5 feet from the home.
SPS 321.40(2)(b)4.
4. Every pier shall be supported by a footing. Each footing shall be no less than a nominal 16 inches by 16 inches.
SPS 321.40(2)(b)5.a.
a. One nominal 4–inch by 16–inch by 16–inch solid concrete block or 2 nominal 4–inch by 8–inch by 16–inch solid concrete blocks. If a single block pier and 2 footing blocks are used, the 2 footing blocks shall be positioned with the joint parallel to the main frame. If a double block pier and 2 footing blocks are used, the 2 footing blocks shall be positioned with the joint either parallel or perpendicular to the main frame.
SPS 321.40(2)(b)5.b.
b. A 16–inch by 16–inch pad constructed of acrylonitrile-butadiene-styrene (ABS) having a rated load bearing capacity of not less than 6000 pounds.
SPS 321.40(2)(b)5.c.
c. An 18–inch diameter hole bored to below the frost line or to unfractured bedrock and filled with poured concrete.
SPS 321.40(2)(b)6.
6. Piers shall be constructed of concrete blocks, manufactured steel stands or manufactured concrete stands. Manufactured stands shall be labeled for use as piers for manufactured homes.
SPS 321.40(2)(b)7.
7. Piers constructed of single stacked concrete blocks shall be limited to a height of 36 inches. Piers constructed of concrete blocks and exceeding 36 inches but less than 80 inches shall be constructed using double stacked blocks with each layer opposing the direction of the layer underneath it. Piers constructed of concrete blocks and exceeding 80 inches shall be constructed using double blocks laid in concrete mortar with each layer opposing the direction of the layer underneath it and with each core filled with concrete and a
½–inch steel reinforcing rod.
SPS 321.40(2)(b)8.
8. All concrete blocks shall be 2–core design, construction grade blocks having nominal dimensions of at least 8 inches by 8 inches by 16 inches. All concrete blocks shall be placed with the cores open vertically. The concrete block nearest the main frame of the manufactured home shall be perpendicular to the linear direction of the frame. None of these concrete blocks may contact the main frame of the home.
SPS 321.40(2)(b)9.
9. Alternative materials may be used for pier installations provided they are approved in advance by the department.
SPS 321.40(2)(b)10.
10. Piers shall be placed under the main frame of the chassis at intervals of not more than 7 feet on–center and no more than 3 feet from the exterior side of each end wall. The 7–foot spacing requirement may be varied as permitted by footing, spacing and soil capacity tables provided by the home manufacturer.
SPS 321.40(2)(b)11.
11. Piers shall be placed under the bearing points of clear–span openings of 4 feet or more in center mating walls.
SPS 321.40(2)(b)12.
12. Piers shall be plumb and centered under the contact area at the point of support.
SPS 321.40(2)(b)13.a.a. Each pier shall be capped with a solid concrete block at least 4 inches thick or a solid wood block having a nominal thickness of at least 2 inches.
SPS 321.40(2)(b)13.d.
d. Two-piece caps shall be positioned with the joint perpendicular to the main frame.
SPS 321.40(2)(b)14.
14. Where shims are utilized, wood shims shall be installed between the pier cap and the frame. Shims shall be driven from opposing sides and shall be no less than 4 inches by 8 inches.
SPS 321.40(2)(b)15.
15. Wood caps and shims shall be at least equal to No. 2 spruce pine fir having a minimum fiber bending stress rating of 1200 psi. All wood caps shall be the same species of wood, and all shims shall be the same species of wood.
SPS 321.40(2)(b)16.
16. The combination of a nominal 2-inch solid concrete block or a nominal 2-inch wood cap plus shims shall not exceed 3
½
inches.
SPS 321.40(2)(b)17.
17. A minimum clearance of 12 inches shall be maintained beneath the lowest point of the main frame in the area of any utility connection. A minimum clearance of 12 inches shall also be maintained under the home for at least 75% of the home. The remainder of the home may be less than 12 inches above the ground but may not touch the ground.
SPS 321.40 History
History: CR 05-113: cr.
Register December 2006 No. 612, eff. 4-1-07;
CR 08-043: am. (2) (b) 13.
Register March 2009 No. 639, eff. 4-1-09;
CR 14-017: r. and recr. (1), cr. (2) (title), am. (2) (b) 8.
Register August 2014 No. 704, eff. 9-1-14; correction in numbering in (1) (za) to (zc) made under s.
13.92 (4) (b) 1., Stats.,
Register August 2014 No. 704; correction in (1) (p) (intro.) made under s.
13.92 (4) (b) 7., Stats.,
Register August 2014 No. 704; corrections in (1) (g) to (i) made under s.
35.17, Stats.,
Register August 2014 No. 704;
CR 15-034: am. (1) (a)
Register December 2015 No. 720, eff. 1-1-16;
CR 21-047: renum. (1) (b) to (1) (b) 1., cr. (1) (b) 2., (c) 2m. Register May 2022 No. 797, eff. 6-1-22.
