Code of Maine Rules
02 - DEPARTMENT OF PROFESSIONAL AND FINANCIAL REGULATION
385 - MANUFACTURED HOUSING BOARD
Chapter 900 - USED MANUFACTURED HOME INSTALLATION STANDARD
Appendix 385-900-D - Ground Level Installation of Used Manufactured Homes (Floor at Grade)
I. Site Preparation Detail I
A. This detail may be used on any foundation site that:
1. Does not contain any mud, organic silt or uncontrolled fill; and
2. The highest ground water table is more than 24" below the finish grade.
B. Refer to Appendix A(III) Installation Zones to determine the required compacted fill depth under the footings or slab.
C. Construction may be placed on naturally occurring soils after all organic material has been removed from the construction site.
D. Compacted fill may be placed below the original site grade only if a drainage system is installed in the fill to prevent the accumulation of water within 24" of the bottom of the footing.
E. Finish grade shall be loamed and seeded with grass or otherwise finished to prevent erosion of compacted fill.
II. Site Preparation Detail II
A. This detail may be used on any foundation site that:
1. Does not contain any mud, organic silt or uncontrolled fill; and
2. The highest ground water table is within 24" of the finish grade
B. If a concrete slab is to be constructed on this site, crushed rock must be installed under the entire concrete slab.
C. A drainage swale at least 6" deep and within 10' of the sidewalls of the home must be constructed around the home.The swale shall have an unobstructed discharge allowing water to flow away continuously from the perimeter of the home.
D. The 4" drainage system shall provide for free flow of water from the rock pads and shall prevent the accumulation of any water.
E. Finish grade shall be loamed and seeded with grass or otherwise finished to prevent erosion of compacted fill.
III. Footing Detail I
A. Concrete shall have a minimum compressive strength of 3000 psi at 28 days
B. Concrete shall be protected from freezing for the first 7 days after it has been cast.
C. Footing pads may be cast on site or precast and delivered to the site for placing.
D. Footing pads which are precast for later placement shall be cured at least 7 days prior to handling.
IV Footing Detail II
A. This detail is of a wood isolated footing to be placed on a prepared site.This detail may be used when pier height does not exceed 30".
B. Wood used in this detail must be southern yellow pine, #2, pressuretreated with water-borne preservatives in accordance with AWPA Standard U1 to the requirements of UC4, ground contact applications.
C. Pier concrete blocks shall be centered on the wood footing with the 16" dimension parallel to the (3) 2" x 8" pressure-treated boards.
V. Pier Detail
A. This detail applies to piers which are a maximum of 24" high from the top of the footing.
B. Masonry units in this detail shall comply with ASTM C90.
C. Wood block shall be of a structurally graded lumber with the 12" dimension centered under the main frame.No more than 2 wood blocks may be stacked.
D. Shims shall provide contact between the main frame and the 2" x 10" for at least 6".
VI. Concrete Slab Detail
VII. Support Location Detail I
A. This detail may be used for home support locations when:
1. The manufacturer's installation instructions are not available; and
2. The home's floor frame is constructed with 2" x 8" or wider floor joists; or
3. The home's floor frame is 12' or less wide
B. Support locations are required within 2' of the end of the main frame and at no more than 8' o.c. under the main frame.
VIII. Support Location Detail II
A. This detail may be used for home support locations when:
1. The manufacturer's installation instructions are not available; and
2. The home's floor frame is constructed with 2" x 4" or 2" x 6" floor joists; or
3. The home's floor frame is more than 12' wide
B. Support locations are required within 2' of the end of the main frame and at no more than 8' o.c. under the main frame.Continuous perimeter support is required under side walls of the unit.See Exception below.
IX. Continuous Perimeter Blocking Detail
A. This detail applies where continuous perimeter blocking or support is required.
B. Ventilation openings shall be provided through sheathing as required by Subchapter B(VII) to this Chapter.
C. Accessopenings shall be provided to the underside of the home as required by Subchapter B(VII)(E) to this Chapter.
D. Pressure-treated lumber shall be treated in accordance with AWPA Standard U1 to the requirements of UC3, above ground applications.
E. Sheathing shall be provided with protection against weather deterioration.
