Words we use
A short glossary, and the questions people ask.
Words
- Mullion, vertical
- The upright framing member between lites. A jamb is the vertical at each end.
- Horizontal
- A cross member between lites; the sill and head at the bottom and top.
- Tie-back
- An anchor to the structure partway up a mullion, usually at a floor line.
- Span
- The length of mullion between two anchors.
- Heavy wall
- A mullion of the same depth with thicker walls, stiffer and stronger.
- Expansion vertical
- A two-piece vertical in a long storefront that lets the frame grow and shrink with temperature. It is lighter than the mullions beside it and is checked on its own.
- Zone 4, Zone 5
- The wind pressure zones on the wall: the field, and near the building's corners where suction is higher.
- ASD, ultimate
- Allowable stress design loads, and the larger strength-design loads; ultimate wind times 0.6 is ASD.
- U-factor
- Heat flow through the assembly, Btu/hr·ft²·°F; lower is better.
- SHGC
- Solar heat gain coefficient: the share of the sun's heat the glass lets in.
- Head receptor
- A storefront head channel the frame slides in, so the structure above can move.
- CHECK
- Something to confirm: an assumption, a near-limit pass, or an item outside the screen.
Questions
- Is this a structural calculation?
- No. It's a preliminary sizing screen to set depths and expectations early. It's never signed, sealed or stamped; the delegated-design engineer does the final design after award.
- Why does an elevation need more depth than I expected?
- Usually the span between anchors, or Zone 5. Open Full results: the depth table names the member that governs. A tie-back at a floor line often brings it back to standard mullions.
- Why does it say REGIONAL?
- The wind is from a wind speed, not the engineer's table. Add the table when it's issued.
- A number I left blank shows as missing.
- Blank stays blank, never zero. Fill it in, or the check uses the stated default and says so.
- Can I use it on a phone?
- Yes: the sections sit in a row under the menu, and every page works at phone width.