Multi Span Structures

multi 6865The Multi-Span Building is an all-steel building designed by Seagrave Building Systems. The building width and length are measured from the outside face of girt to the outside face of girt. The building height is measured from the underside of base plate level to the intersection of the girt line and top of the roof purlins. The roof profile is a symmetrical gable.

Individually designed, welded rigid frames, using continuity over interior supporting members span the entire width of the building. Each rigid frame consists of two tapered exterior columns and rafters as required depending on the spans. The maximum depth of section occurs at the haunch. The interior columns are equally spaced across the width of the building and are basically compression members transferring a portion of the roof load to the foundation. Seagrave Building Systems supplies the structural system, wall and roof cladding, flashings and fasteners ready for erection. Field connection of structural framing is made by bolting.


Roof Slope

1″ in 12″ Standard, 1/4″ in 12″ to 6″ in 12″ inclusive, is optional.


Standard accessories such as door and window openings, translucent wall lights, translucent skylights, gutters, downspouts, eave trim and factory applied colours for the coverings are supplied when ordered.

Standard Building Sizes

Building sizes are provided as ‘standard’ and are to be used as a basis from which ‘non-standard’ buildings may be estimated for their member sizes, clearances, foundation reactions, etc.

Standard Frame Design Loads

The frame designs are tabulated by live load which is normally the roof snow load multiplied by the tributary length carried by the frame in question. You must add any collateral loads, if required (ie mechanical, electrical, sprinkler, ceiling, insulation etc.) to the live load when selecting the appropriate standard frame design. The dead load allowance includes the weight of the frame itself plus 4 psf for purlins, roof cladding and bracing. The wind load is based on a q(1/30) of 10 psf. Both the dead load and wind load assume a 25′ bay.

Special Structural Requirements

The standard building sizes shown in this section do not indicate the full range. Upon request, Seagrave Building Systems will perform the necessary structural design investigation when special building sizes, excessive live loads, wind loads or dynamic loads from material handling systems (cranes, hoists, etc) are required. The building frame, etc. will then be determined for the conditions specified.