Mobile Home Pads in Tennessee
A pad is required for all new mobile home installations in Tennessee. A pad is simply a flat area to install a mobile home, where the ground is crowned to shed water away from the home’s foundation. Below are some considerations and requirements for these pads.
To help prevent settling or sagging, the home shall be sited on firm, undisturbed soil or fill compacted to at least 90 percent of its maximum relative density. The bearing capacity of the soil shall be determined before the foundation is designed.
If the soil capacity cannot be determined by either local soil records or by tests, but its type can be identified, the foundation bearing pressures shown in Table 5.5.2.2 shall be permitted to be used.
If the bearing capacity of the soil cannot be identified, Table 5.5.2.2 shall be used unless the soil appears to be composed of peat, organic clays, or uncompacted fill or appears to have unusual conditions. In this case, a registered professional geologist, a registered professional engineer, or an architect shall be consulted. A pocket penetrometer or any other method acceptable to the authority having jurisdiction shall be permitted to be used.
Removal of all decayable material, such as grass, roots, twigs, and wood scraps, from beneath the home is required in areas where footings are to be
placed, to minimize settling of footings and insect damage.
Drainage shall be provided that prevents water build-up under the home, shifting or settling of the foundation, dampness in the home, damage to siding and bottom board, buckling of walls and floors, and problems with the operation of doors and windows. The home site shall be graded to permit water to drain from under the home. (See Figure 5.7.2.1.1.) All drainage shall be diverted away from the home.
Sloped sites shall be protected from surface runoff from the surrounding area. Ditches and culverts shall be permitted to be used to drain surface runoff and to be included in the overall site preparation. When gutters and downspouts are installed, the runoff shall be directed away from the
home.
If the space under the home is to be enclosed with skirting or other material, a vapor retarder that keeps ground moisture out of the home shall be installed except in arid regions with dry soil conditions or where approved by the authority having jurisdiction. A minimum of 6-mil (0.15 mm) polyethylene sheeting or its equivalent shall be used, and it shall be overlapped at least 12 in. (305 mm) at all joints.
Where soil and frost conditions permit placement of footings at grade level, the sheeting shall be placed directly beneath the footings.
Additional Resources
ANSI A225.1 2003 HUD Code – Used Home Standards
Clayton Homes Site Construction Manual – New Home Standards