Pre-Engineered Frame Structures

Engineered Membrane Systems for Frame Structures

A pre-engineered frame structure is a building whose loads are carried by a rigid aluminum or steel frame, with a tensioned fabric membrane as the roof and walls. The frame comes from a repeatable, engineered kit of parts, which is what makes these buildings fast: modular and semi-custom rather than designed from scratch, and a practical permanent or temporary alternative to brick-and-mortar for warehousing, recreation, athletics, agriculture, and industrial cover.

Lightweight Structures manufactures the fabric side of that system. We engineer and fabricate the membrane panels that clad the frame: single-bay kedered panels, large multi-bay panel systems, gable and end-wall panels, and replacement skins for frames already standing in the field. We do not sell the frame kit or the finished building; we make the fabric system that closes it in, and the engineering that proves it works.

Keder Panels or a Large Panel System?

Both are standard practice, and the frame usually decides which one you want.

Keder panels are the common choice for permanent frame-supported structures, because the connection is reliable and easy to install: a rectangular panel slides into the rail and stays attached to the frame through every phase of the installation. In aluminum frame systems the keder track is already part of the main extrusions at no extra cost, so we connect the fabric to it almost every time. On a steel frame, an aluminum keder rail is added on top of the frame, which adds material and installation labor. That is worth it when panel-by-panel replaceability matters. New to the detail? Start with what keder is.

Large panel systems suit steel frame-supported buildings. We tension them with pipes and pockets at the panel edges, and because the frame shape does the work the panel can span several bays without attaching to intermediate arches. Fewer seams in the field, fewer connections to detail, faster close-in.

We fabricate both from the material the project calls for: PVC-coated polyester, polyethylene, PTFE-glass, ePTFE, and fluoropolymer films. Specifications for the fabrics we work with most are in our document library.

Engineering for Frame Structures

Even with a pre-engineered frame, the membrane is engineered work. Panel loads have to transfer into the frame at the connections the frame actually provides; snow and water have to shed where the geometry sends them; and the assembly has to satisfy the codes and load cases of the jurisdiction the building sits in, not a generic one. Our engineering and design team produces the patterning, the connection detailing with your frame supplier, the shop drawings, and professional engineer certification where the project requires it. See design and engineering services.

Who Installs the Structure?

Lightweight Structures does not install. Your project is completed by our network of certified installation partners. Frame erection and panel installation are handled by crews who assemble these buildings routinely, and we hand off drawings, panel schedules, and keder details they can work from. Where a specifier or general contractor has no crew in mind, we work with installers who are already familiar with our panels, our keder details, and our engineering.

Scope is defined from the ground up. Foundations and attachment structures are specified but excluded from our scope; our engineers provide the reactions at every anchor point so your local engineer can design those elements for the same loads under the governing building code.

Where Does the Fabric Come From?

A frame structure lives or dies on the membrane spec: strength for the loads, coating for the environment, and a top finish that stays clean and holds color. We are not a fabric distributor. Every membrane we quote is a material we engineer and fabricate with, chosen for the loads, the lifespan, the light transmission, and the finish your project needs.

Behind that choice is a fabric maker. Lightweight Structures is part of Seaman Corporation, which has been making industrial coated fabrics in the United States since 1949: yarn, weaving and knitting, coating, finished membrane, all under one roof. A coating or finish question on a frame package is answered by the people who made the material.

If what you need is the fabric itself rather than a fabricated panel system, that is Shelter-Rite Architectural Fabrics, the Seaman Corporation brand for architectural membrane. Companies that build frame structures and buy membrane by the roll should start there. Same company, different starting point; we will point you to the right one rather than sell you the wrong one.