24 CFR § 3285.802 - Structural interconnection of multi-section homes.
(a) For multi-section homes, structural interconnections along the interior and exterior at the mate-line are necessary to join all sections of the home.
(b) Structural interconnection must be designed in accordance with the requirements located in § 3280.305 of this chapter to ensure a completely integrated structure.
(c) Upon completion of the exterior close-up, no gaps are permitted between the structural elements being interconnected along the mate-line of multi-section homes. However, prior to completion of the exterior close-up, gaps that do not exceed one inch are permitted between structural elements provided:
(1) The gaps are closed before completion of close-up;
(2) The home sections are in contact with each other; and
(3) The mating gasket is providing a proper seal. All such gaps must be shimmed with dimensional lumber, and fastener lengths used to make connections between the structural elements must be increased to provide adequate penetration into the receiving member.