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QUOTE STUDIO
Field Guide

Frame · Zees, Cees, girts, purlins

Secondary framing

Orientation is on the drawings. Lap bolts in the outermost holes. Block girts to L/500 before you sheet. Do not land panel bundles on unsupported purlins.

zee
cee
girt
purlin
bypass
flush

Standard and flipped

Erection drawings show which members are standard and which are flipped. Secondary connections snug-tight unless the drawings say otherwise. That includes Zee/Cee purlins, Zee/Cee girts, eave struts, opening members, truss purlins, bar joists, flange braces, and bolted clips. Washers over slotted holes in secondary are not required per AISI.

Standard Zee purlin vs flipped Zee; standard Zee girt vs flipped; standard Cee girt vs flipped.

Girt laps

Recommended procedure for a safe lap: attach the first member to the clip with bolts and retainer as shown. Install the second member over the first and the retained bolt. Install remaining bolts and nuts to complete the lap. Bolt retainers are commercially available. Orientation is critical — install the retainer so the prongs point out.

Bolt retainer on the first member. Second member nests over it. Prongs point out.

Wall girt blocking

Temporary blocking of girts is required to hold them straight and level prior to panel. Girts and purlins shall be straight to L/500. Blocking at midbay is by the erector.

H/500 · plumb & straight

Columns plumb to height/500. Beams, girts, and purlins straight to span/500.

± L / 500

5⁄8″

Allowable departure from plumb or straight. 300″ of member · 0.600″ decimal.

Guide example: 25 ft → ±⅝″.

Roof purlin blocking

Roof-panel bundles often sit on the purlins before installation. That will damage unsupported purlins. If bundles land on the roof, follow this:

  1. All structurals, flange bracing, sag angles, and temporary bracing must be in place and plumb. Tighten bolts before you block. Installed and panel bundles are placed on the roof only after that.
  2. Panel bundles sit over centerlines of frames — not over joist bridging or jack trusses.
  3. Install blocking between all purlins at all frames where bundles will sit. Blocking length equals purlin spacing. 2×6, or larger if the erector needs it. Purlin depth minus ⅝″ is a typical cut.
  4. Remove blocking after panels are installed.
  5. Install all purlin channel braces or sag bracing BEFORE roof panels. See the drawings for locations.
Bundles over frame centerlines only. 2×6 blocking between purlins at those frames. Remove after sheeting.
Alternate blocking runs the slope. Channel braces / sag angles in before panel.