What Is a Permanent Foundation for a Mobile Home?

The U.S. Department of Housing and Urban Development provides comprehensive guidelines for permanent foundations on mobile homes. Following these guidelines ensures the foundation will hold up to inclement weather, stay safe and allow for easy access to mechanical equipment.

  1. Materials

    • Foundations should be made of concrete, treated wood or masonry. Backfill, the substance used to fill the foundation's empty spaces, should be pure and free of undesirable materials like small pieces of wood. Beams and pipe columns should be steel and footings (the bottom part of the foundation) must be concrete.

    Measurements

    • The foundation should extend below the part of the ground affected by frost and moisture. Foundation walls must extend at least eight inches above the finished grade. Wall thickness should be at least six inches and pier or pier footing (columns or blocks above the bottom of the foundation) must be at least eight inches.

    Crawlspace

    • Permanent foundations must include a crawlspace that measures 12 inches from the bottom of the chassis beam and 18 inches from the bottom of the wood floor joists. Where access is needed to perform maintenance, the area that houses mechanical equipment must be no less than two feet from the wood floor joists. Openings and access points must be located against the long walls of the foundation.