Patent Publication Number: US-2010107517-A1

Title: Structural brace for modular housing module

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to prefabricated housing modules. In particular, the present invention relates to structural support for transporting a prefabricated housing module from its manufacturing site to its installation site. 
     2. Discussion of the Related Art 
     Prefabricated housing derives its cost advantage by performing many of the assembly steps required for a housing unit at the factory, rather than at the job site. The building block for multi-unit prefabricated housing is typically the individual pre-fabricated modules. A typical module may include one or more bedrooms, a living room, a kitchen and a bathroom. Each module, typically including all of its exterior and interior walls, is manufactured and assembled at a manufacturing facility and transported to the building site for further assembly (if required) and for installation into the multi-unit structure. At a building site, a concrete foundation is typically prepared, to which a pre-fabricated module is attached and fastened. Typically, for efficiency reasons, the pre-fabricated module and the foundation are both provided means for the attachment and fastening ahead of the installation time. For a multi-story unit, a second floor module is then stacked on top of and fastened to the first floor unit. If the multi-unit structure has additional stories, additional modules are similarly stacked and fastened to the story immediately underneath. If the multi-unit design includes abutting side by side modules, the abutting modules are placed along side each other and fastened along the abutting exterior walls. 
     It is not unusual to transport a prefabricated module hundreds of miles to an installation site. Therefore, the prefabricated module must have structural integrity that can withstand the forces experienced on the road. Typically, structural integrity is provided by the module&#39;s exterior load-bearing side walls and a structural floor and a structural ceiling. As a result, a multi-unit housing unit built with these modules has both a structural floor and a structural ceiling between two floors, and two load-bearing walls between abutting side by side units. In contrast, in custom-built housing, structural integrity can be provided by a single load-bearing structure between floors or between side by side adjacent units. The redundant walls, ceilings and floors in prefabricated modules add significant cost, and because the redundancy is not needed in the final building structure, the additional material is wasted. 
     SUMMARY 
     According to one embodiment of the present invention, a structural brace for a pre-fabricated housing module includes (a) a temporary beam connecting two opposite side walls of the pre-fabricated housing module along an open side of the pre-fabricated housing module; (b) ceiling bracing panels each providing horizontal temporary structural support between a third side wall of the pre-fabricated housing module and the temporary beam; and (c) wall bracing panels each providing temporary vertical structural support between the temporary beam and a floor of the pre-fabricated module. A further transverse beam may be provided to connect the ceiling bracing panels for greater structural support and to facilitate lifting of the module during transportation. A tarp may be provided to cover the top and any exposed side of the pre-fabricated housing module to prevent damage to the interior on route to an installation site. 
     According to one embodiment of the present invention, a ceiling bracing panel includes a base board and a number of dimensional lumber pieces secured to the base board which are placed substantially parallel to each other and spaced at predetermined intervals. A wall bracing panel may be similarly provided. 
     The structural brace of the present invention may include steel blocks that secure the ceiling panels to the studs of a side wall of the pre-fabricated housing module, so as to allow the side wall to bear the weight of the pre-fabricated housing module when it is moved. Additional structural support is achieved using hold downs bolted to structural elements of the side wall. Sound deadened steel plates may be provided for reducing sound and vibration during transportation. 
     n one embodiment, the structural brace of the present invention is a temporary structure that provides structural strength to the prefabricated housing unit, as the prefabricated housing unit is moved between manufacturing and installation sites. Possibility of the housing unit suffering damages on route to the building site is therefore greatly reduced. The structural brace is removed at the time of installation. The removed structural brace can be returned to the manufacturing facilities to be reused. The structural brace of the present invention therefore eliminates need for redundant walls, floors and ceilings, thus reducing the waste, as compared to the prior art. 
     The present invention is better understood upon consideration of the detailed description below and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows prefabricated housing module  100  before being provide a structural brace. 
         FIG. 2  shows prefabricated module  100  of  FIG. 1  being provided a structural brace for maintaining structural integrity during transportation, in accordance with one embodiment of the present invention. 
         FIG. 3  shows tarp  300  being provided over module  100  to provide a covering for module  100  during transportation between the manufacturing facilities and the building site. 
         FIG. 4  is an axonometric view of ceiling panel  201 . 
         FIG. 5  shows a cross section of installed structural brace  200 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     According to one embodiment of the present invention, a structural brace is developed to provide a prefabricated housing module structural integrity during transportation between a manufacturing facility and a building site where the module is to be installed. 
       FIG. 1  shows prefabricated housing module  100  before being provided a structure brace. As shown in  FIG. 1 , prefabricated module  100  is open at one side wall and is not provided a structural ceiling. Module  100  includes permanent prefabricated external side walls  101   a,    101   b  and  101   c,  and a structural floor  108 . Window frames  102  have been provided and installed in external side walls  101   a  and  101   b.  Module  100  also includes multiple rooms with multiple interior dividing walls  103  installed at the manufacturing facilities. Module  100  is a “building envelop,” to which other interior amenities, such as cabinets, closets, stairs and plumbing connections, are installed at the building site. These other amenities may be separately manufactured at different manufacturing facilities (or supplied by other vendors) and provided as modular “cells” for installation at the building site. 
     According to the present invention, as module  100  is a unit which abuts a neighboring unit on one of its sides and with another unit stacked on top, a structural side wall and a structural ceiling is not included. At the building site, module  100  is attached and fastened on its open side to another unit that has a structural side wall. Similarly, at the building site, another module with a structural floor is attached and fastened to the open top to module  100 , so that the structural floor of the other unit provides the ceiling for module  100 . According to this design, therefore, redundant ceilings and side walls are eliminated to achieve material efficiency. 
       FIG. 2  shows prefabricated housing module  100  being provided structural brace  200  for maintaining structural integrity during transportation, in accordance with one embodiment of the present invention. As shown in  FIG. 2 , structure brace  200  includes temporary beam  204 , ceiling bracing panels  201  and wall bracing panels  202 . Ceiling bracing panels  201  are held down by steel blocks and hold downs secured on the studs of external side wall  101   b  (see  FIG. 5 ). In addition, ceiling bracing panels  201  are connected in a transverse direction by standard size dimensional lumber  203  (shown in  FIG. 3 ). Standard size dimensional lumber  203  may be provided, for example, by a 2×6 piece (i.e., two inches by six inches).  FIG. 3  shows tarp  300  being provided over module  100  to provide a covering for module  100  during transportation between the manufacturing facilities and the building site, to be removed immediately prior to installing module  100  at the building site. Tarp  300  protects the interior of prefabricated module  100  against external elements by covering the open ceiling and side. As shown in  FIG. 3 , module  100  can be moved by a crane using steel cables which are attached to the load-bearing structures provided on structural braces  200 . 
       FIG. 4  is an axonometric view of ceiling panel  201 . As shown in  FIG. 4 , ceiling bracing panel  201  includes a base board  401 , which can be provided by a ½-inch thick plywood board. On base board  401  is provided 2″×4″ dimensional lumber pieces spaced at 24″ apart (on center). Wall bracing panels  202  can be similarly constructed. 
       FIG. 5  shows a cross section of installed structural brace  200 . As shown in  FIG. 5 , ceiling bracing panel  201  is secured on one side to external side wall  101   b,  which may be provided by a conventional double stud party wall, and on the other side to wall bracing panel  202 . Steel blocks  501  are secured to the double stud party wall  504  by ⅝″ bolts (indicated by reference numerals  503 ), so that the weight of module  100  can be borne in the studs in the wall. In addition, hold-downs  505  (e.g., HD5A or HTT16) may be provided for further support by horizontal members in the double stud party wall. Ceiling bracing panel  201  and wall bracing panel  202  are attached to temporary beam  204 , which may be provided by 4″×8″ dimensional lumber  505 . 
     As discussed above, wall bracing panel  202  may be provided substantially the same structure as ceiling bracing panel  201  (e.g., dimensional lumber (e.g., 2×4&#39;s) secured to a base board and spaced apart at regular intervals). A riser (indicated by reference numeral  507 ) having, for example, the construction of small sections of a double stud party wall, may be provided from floor  108  of prefabricated module  100  to allow wall brace panel  202  to attach. Such a riser structure would allow wall brace panel  100  to be attached to module  100  in substantially the same manner as ceiling panel  201  attaches to side wall  101   b.  In one embodiment, sound deadened steel (SDS) plates  506  are provided for attachment to floor  108  of module  100  to limit sound and vibrations in wall bracing panel  202 . 
     The detailed description above is provided to illustrate specific embodiments of the present invention and is not intended to be limiting. Numerous variations and modifications within the scope of the present invention are possible. The present invention is set forth in the following claims.