02-385-890 Me. Code R. § D-III

Current through 2024-51, December 18, 2024

Section 385-890-D-III - Piers

A.General

The piers used must be capable of transmitting the vertical live and dead loads to the footings or foundation.

B.Acceptable Piers - Materials Specification

1. Piers are permitted to be concrete blocks, pressure-treated wood with a waterborne preservative, in accordance with AWPA Standard U1-04 (incorporated by reference) for Use Category 4B ground contact applications; or adjustable metal or concrete piers.

2. Manufactured piers must be listed or labeled for the required vertical load capacity, and, where required by design, for the appropriate horizontal load capacity.

C.Design Requirements

1.Load-bearing capacity

The load-bearing capacity for each pier must be designed to include consideration for the dimensions of the home, the design dead and live loads, the spacing of the piers, and the way the piers are used to support the home.

2. Center beam/mating wall support must be required for multi-section homes and designs must be consistent with Tables 2 and 3 of this section and Figures A, B, and C to Subchapter D, Section X.

D.Pier Loads

1. Design support layout configurations for the pier loads, pier spacing, and roof live loads must be in accordance with Tables 1, 2 and 3 of this section and the MHCSS.

2. Other pier designs are permitted in accordance with this subchapter.

3. Manufactured piers must be rated at least to the loads required to safely support the dead and live loads, as required by Subchapter D, Section I, and the installation instructions for those piers must be consistent with Tables 1, 2, and 3 of this section.

Table 1 to Subchapter D, Section III - Piers

Frame Blocking Only - Perimeter Support not Required Except at Openings

Pier spacing	Roof live load (psf)	Location	Load (lbs.)
4 ft. 0 in. ..........................................	20 30 40	Frame .................................................................. Frame .................................................................. Frame ..................................................................	2,900 3,300 3,600
6 ft. 0 in. ...........................................	20 30 40	Frame .................................................................. Frame .................................................................. Frame ..................................................................	4,200 4,700 5,200
8 ft. 0 in. ............................................	20 30 40	Frame .................................................................. Frame .................................................................. Frame ..................................................................	5,500 6,200 6,900
10 ft. 0 in. ............................................	20 30 40	Frame .................................................................. Frame .................................................................. Frame ..................................................................	6,800 7,600 8,500
10 ft. 0 in. ..........................................	20 30 40	Frame .................................................................. Frame .................................................................. Frame .....................................................	6,800 7,600 8,500

Notes to Table 1:

1. See the Table to Subchapter D, Section XII for cast-in-place footing design by using the noted loads.

2. Table 1 is based on the following design assumptions: maximum 16 ft. nominal section width (15 ft. actual width), 12" eave, 10" I-beam size, 300 lbs. pier dead load, 10 psf roof dead load, 6 psf floor dead load, 35 plf wall dead load, and 10 plf chassis dead load.

3. Interpolation for other pier spacing is permitted.

4. The pier spacing and loads shown in the above table do not consider floor or seismic loads, and are not intended for use in flood or seismic hazard areas. In those areas, the foundation support system is to be designed by a professional engineer or architect.

5. See the Table to Subchapter D, Section XII for sizing of footings.

Table 2 to Subchapter D, Section III - Piers

Frame Plus Perimeter Blocking/Perimeter Blocking Required

Maximum pier spacing	Roof live load (psf)	Location	Load (lbs.)
4 ft. 0 in. .......................................................................	20	Frame ...........................................................................Perimeter ......................................................................Mating ...........................................................................	1,400 1,900 3,200
4 ft. 0 in. .......................................................................	30	Frame ...........................................................................Perimeter ......................................................................Mating ...........................................................................	1,400 2,300 3,800
4 ft. 0 in. .......................................................................	40	Frame ...........................................................................Perimeter ......................................................................Mating ...........................................................................	1,400 2,600 4,400
6 ft. 0 in. .......................................................................	20	Frame ...........................................................................Perimeter ......................................................................Mating ...........................................................................	1,900 2,700 4,700
6 ft. 0 in. .......................................................................	30	Frame ...........................................................................Perimeter ......................................................................Mating ...........................................................................	1,900 3,200 5,600
6 ft. 0 in. .......................................................................	40	Frame ...........................................................................Perimeter ......................................................................Mating ...........................................................................	1,900 3,700 6,500
8 ft. 0 in. .......................................................................	20	Frame ...........................................................................Perimeter ......................................................................Mating ...........................................................................	2,400 3,500 6,100
8 ft. 0 in. .......................................................................	30	Frame ...........................................................................Perimeter ......................................................................Mating ...........................................................................	2,400 4,200 7,300
8 ft. 0 in. .......................................................................	40	Frame ...........................................................................Perimeter ......................................................................Mating ...........................................................................	2,400 4,800 8,500
10 ft. 0 in. .....................................................................	20	Frame ...........................................................................Perimeter ......................................................................Mating ...........................................................................	2,900 4,300 7,600
10 ft. 0 in. .....................................................................	30	Frame ...........................................................................Perimeter ......................................................................Mating ...........................................................................	2,900 5,100 9,100
10 ft. 0 in. .....................................................................	40	Frame ...........................................................................Perimeter ......................................................................Mating ...........................................................................	2,900 6,000 10,600

Notes to Table 2:

1. See the Table to Subchapter D, Section XII for cast-in-place footing design by using the noted loads.

2. Mating wall perimeter piers and footings only required under full height mating walls supporting roof loads.Refer to Figures A and B to Subchapter D, Section X.

3. Table 2 is based on the following design assumptions:maximum 16 ft. nominal section width (15 ft. actual width), 12" eave, 10" I-beam size, 300 lbs. pier dead load, 10 psf roof dead load, 6 psf floor dead load, 35 plf wall dead load, and 10 plf chassis dead load.

4. Interpolation for other pier spacing is permitted.

5. The pier spacing and loads shown in the above table do not consider floor or seismic loads and are not intended for use in flood or seismic hazard areas.In those areas, the foundation support system is to be designed by a professional engineer or architect.

6. See the Table to Subchapter D, Section XII for sizing of footings.

Table 3 to Subchapter D, Section III - Piers

Ridge Beam Span Footing Capacity

Mating wall opening (ft)	Roof live load (psf)	Pier and footing load (lbs.)
5 ................	20 30 40	1,200 1,600 1,900
10 ..............	20 30 40	2,300 3,100 3,800
15 ..............	20 30 40	3,500 4,700 5,800
20 ..............	20 30 40	4,700 6,200 7,500
25 ..............	20 30 40	5,800 7,800 9,700
30 ..............	20 30 40	7,000 9,300 11,600
35 ..............	20 30 40	8,100 10,900 13,600

Notes to Table 3:

1. See the Table to Subchapter D, Section XII for cast-in-place footing design by using the noted loads.

2. Table 3 is based on the following design assumptions:maximum 16 ft. nominal section width (15 ft. actual width), 12" eave, 10" I-beam size, 300 lbs. pier dead load, 10 psf roof dead load, 6 psf floor dead load, 35 plf wall dead load, and 10 plf chassis dead load.

3. Loads listed are maximum column loads for each section of the manufactured home.

4. Interpolation for maximum allowable pier and column loads is permitted for mate-line openings between those shown in the table.

5. The pier spacing and loads shown in the above table do not consider flood or seismic loads, and are not intended for use in flood or seismic hazard areas.In those areas, the foundation support system is to be designed by a professional engineer or architect.

6. See the Table to Subchapter D, Section XII for sizing of footings.

02-385 C.M.R. ch. 890, § D-III