Section Inst 603.02 - Site Preparation Systems(a) This section prescribes standards for siting, design and installation of manufactured house support systems. It shall be applicable to all new and relocated manufactured houses when and wherever newly installed at a house site.(b) The house shall be designed to meet the New Hampshire wind, snow roof loads, and climatic conditions as described on the manufactured house data plate. Houses that are designated on the manufacturer's data plate in a low pounds per square foot (PSF) snow zone, which includes 30 PSF shall not be installed in a higher roof load zone.(c) The house shall be able to be safely moved to the site, which should be free of branches, holes in the ground and hanging wires to prevent any preliminary damage to the house.(d) A manufactured house support system shall be constructed in accordance with one of the following: (1) Manufacturer's installation manual instructions;(2) Foundation design by a New Hampshire licensed professional engineer or architect; or(e) Site preparation shall be in accordance with general residential construction practices.(f) Houses shall not be constructed in any naturally occurring seasonal drainage swale. In order to prevent moisture under the house, which can cause settling of the support system and deterioration to the house, water shall not be able to accumulate or stand under the house.(g) Gravel or concrete slab under the house shall be crowned 1 to 2 % along the longitudinal center line of the house.(h) All drainage shall be diverted away from the home and must slope a minimum of one-half inch per foot away from the foundation for the first 10 feet. Where property lines, walls, slopes, or other physical conditions prohibit the slope, the site shall be provided with drains or swales or otherwise graded to drain water away from the perimeter of the house.(i) A vapor retarder shall be used above the gravel or below the concreteif the house is enclosed by skirting to keep ground moisture out. If overlap of the polyethylene is required, it shall be at least 12 inches at all joints.(j) The fire separation distance shall be provided, as the state and local authority requires.N.H. Admin. Code § Inst 603.02
#8494, eff 12-24-05; ss by #10155, eff 4-14-12