New Guide for Tiny House On Wheels Floor Assemblies
1. Scope
This guide covers the design and construction of floor assemblies for Tiny Houses on Wheels that are permanently structurally integrated with the trailer chassis.
It covers different trailer types in common use and the types of floor assemblies appropriate to each, including wood joist assemblies built above chassis crossmembers, steel joist assemblies where the crossmembers double as the floor joists, and hybrid assemblies.
It covers the purpose, design considerations, selection of materials, and installation considerations for each component of the floor assembly.
For wood joist assemblies, it covers framing recommendations for structural soundness of the assembly in conjunction with the chassis deck frame.
It addresses design considerations for prevention of condensation and mold in the floor assembly and the interior floor surface through proper use of insulation, air sealing, and vapor retarders.
It addresses considerations for the use of the floor assembly for plumbing and mechanical runs.
Limitations—It does not cover structural design requirements of the trailer chassis itself or structural connection of the floor to the chassis. As a guide, assemblies are described conceptually and are not prescriptive.
The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Tiny homes on wheels present unique design challenges due to their interface with the trailer chassis. These challenges include structural design of the floor to chassis interface, proper insulation and air sealing to prevent moisture issues and energy loss, and plumbing and mechanical freeze protection. Current building codes do not address these unique considerations in the context of a tiny house built on a chassis.
A lack of industry standards has resulted in a proliferation of practices, some of which have been harmful to the longevity of these structures and the health of their inhabitants. The purpose of this guide is to assist designers, manufacturers, and owner-builders in constructing floor assemblies that will last the life of the structure and protect public health.
