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Manufactured Homes

HUD/FHA Permanent Foundation Inspections

Criterium-Dormady Engineers performs inspections of permanent foundations for manufactured homes for compliance with HUD/FHA requirements.

The Federal Housing Administration (FHA), a division of the U.S. Department of Housing and Urban Development (HUD), insures most mortgages for new or existing manufactured homes. Those homes must have “permanent foundations” that comply with FHA guidelines.

The FHA requires that a licensed Professional Engineer design the permanent foundation for a new manufactured home. For an existing home, a Professional Engineer must certify that the foundation meets the FHA requirements.


HUD/FHA Foundation Requirements

The following improvements beyond the minimum manufactured home installation regulations are necessary to meet the more stringent requirements of the Permanent Foundations Guide for Manufactured Housing, HUD Publication HUD-7584, which must be met for a home to qualify for FHA financing.

  • The foundation piers must bear upon reinforced poured concrete footings that are constructed below the frost line.
  • Foundation piers must be constructed of “solid materials”, such as reinforced concrete, masonry, steel, or treated wood. Dry-stacked block piers, which are commonly used in manufactured home foundations, can be upgraded to meet this requirement by applying an adequate coating of fiber-reinforced surface bonding cement.
  • A permanent well supported perimeter wall (skirting) must enclose the foundation to keep out vermin and water. This wall must be self-supporting and must rest on a concrete footing. An access opening must be constructed in this skirting wall. Most often these walls are constructed of block or brick masonry. However, treated wood walls can qualify if properly constructed.
  • The home must have adequate tie downs anchored to the footings to resist horizontal overturning, transverse and longitudinal loads. HUD-7584 specifically prohibits dependence on screw-in tie-down anchors commonly used in manufactured home anchorage systems. There are several anchorage systems that can be installed to satisfy this requirement. Two examples are illustrated below:
  • The tongue, axles, and wheels must be removed.
  • An adequate number of screened vents must be installed around the entire perimeter of the building to provide air circulation in the crawl space (1 sq. ft. of net free area per 150 sq. ft crawl space floor area).
  • The perimeter walls must extend at least 8 inches above grade.
  • The exterior grade must taper away from the home for drainage.
  • The dirt floor of the crawl space must be covered with 6-mil polyethylene plastic vapor barrier.
  • Utilities must be permanently installed.

This information is provided as a courtesy to help illustrate some of the HUD Permanent Foundation requirements that apply in our local area. This is not a comprehensive list of requirements or a complete manual of accepted good practice. Additional building code and engineering considerations may apply to various situations. Therefore, meeting the requirements listed above does not ensure that the installation can be certified.