To build the superstructure, structural columns, beams, and stiffener plates are applied to a specific manufactured trailer frame.
For when the units are on site and installed on piers:
- Trailer only needs some stiffener plates below the columns (see attached “Stiffened Trailer Beams” jpg)
- Floor Joists are 1200S250-68 (12” x 2.5” x 14ga) @ 24” o.c.
- Roof Joists are 600S250-68 (6” x 2.5” x 14ga) @ 24” o.c.
- Columns/posts are HSS 6x4x1/4”
- Roof Beams are HSS 6x4x1/4”
These are preliminary sizing and are subject to change once a full analysis and calc package is done. Certain connection designs may need to change member sizes.
For the issues:
While Parked / stationary:
- Trailer beam needs some stiffener plates below the columns and above the axles (see attached “Stiffened Trailer Beams” jpg)
While in transportation temporary structure bracing is needed.
Angel Landings system provides a structural design that is easy to assemble and requires minimal leg work to build. We took a trailer chassis from a reputable manufacturer and reinforced it to handle addition vertical load. Once the trailer chassis is fitted with the moment frame it becomes a super structure. By now you must be asking why would I build on top of the chassis? It is quite simple why, first it qualifies for federal agency HUD approval vs local government approval. Second it makes it easy to assemble the super structure off-site and ship it on wheels. Since wheels are attached directly to the structure then in most cases crane is not required to place it on site. Chassis with superstructure simplifies the construction logistic and cost associated with it.
The light frame is easy to assemble either on site and requires no scaffolding or heavy lifting equipment. All one needs is a ladder to assemble.
The chassis is built with a tongue hitch so that one can easily ship it using a tractor trailer truck. Additional axial may be required either for incomplete or complete unit to carry additional load. Each axial can carry around 6000LB of weight.
Please note to qualify for federal approval there are federal agency inspection requirements and are handle by DAPIA (manufactured housing and HUD). If the state jurisdiction prohibits use of Federal code, then one needs to file and inspection under local state modular building code or IBC.
Below please find structure design and calculations. Please note a builder needs to verify with a local engineer if the structural calculation meets local wind and seismic requirements and some cases soil conditions. Also, to file under federal agency DAPIA one needs signed and sealed drawing from a registerer engineer in the USA. Angel Landings can provide these drawings from our structural engineers for a fee.
Builder installing the structure unit onto above ground piers footing would need to attach the piers after the structure is delivered to its location. However, if the footing is installed below ground level, then the footing needs to be professionally installed by a licensed foundation contractor for trailer buildings/homes.
Additional metal accessories are:
- Retractable steps can adjust up to 44 inches. There are good for offsite living where retractable stairs can prevent unwanted fury guest into the unit at night. Please note retractable steps are not IBC compliant and may be unsafe for young kids. To learn more about retractable steps and details please download the metal frame package.
- For exterior finish we recommend Vesta metal panel system. These are corrosion resistant, built strong and have quality imprinted wood grain textures. They are easy to install.
- We recommend using a standard metal wire railing that can be assembled on site easily.
- Painted corrosion resistant steel angle is used to frame the EPDM roofing and roof insulation.