Frame Marquee & Event Tent Fabric: Roof, Gable Ends, Side Walls, Area & Mass

The formula

This is the expression the tool evaluates. Every term is named underneath, with the unit it must be supplied in.

How the result is derived

Step by step, from the values you type to the figure on screen.

1. The 7 inputs are read from the form on every keystroke: Marquee Length, Span (Width), Leg (Eave) Height, Roof Pitch, Valance Overhang at the Eaves, Seams, Hems & Cutting Allowance and Fabric Weight.
2. Each value is checked against the accepted range in the input table below. A value outside its range stops the calculation rather than producing a misleading figure — the results blank out and a message appears.
3. The validated values are substituted into the expression above, which resolves Fabric to Buy together with every supporting figure in one pass — no value is carried over from a previous entry.
4. The supporting outputs — Ridge Height, Roof Slope Length incl. Valance, Roof (Two Slopes), Gable Ends (Two Triangles), Side & End Walls, Fabric in the Cover Set, Cover Set Mass and Floor Area — come from the same pass, so they always describe the same case as the headline figure.
5. Results are rounded for display only. The full-precision value is used throughout the chain, so reading a rounded intermediate figure back into the tool by hand can shift the last digit.

What each input means

Where to read each value on the floor, the unit it must be in, and the range the tool accepts.

What the tool returns

The headline figure and every supporting value it is built from.

Worked example

Substituting

The walls are 82.8 m² against 81.4 m² of roof. A marquee bought "roof only" is half a cover set.

How to use it

1. Work through the input groups in order — Frame and Fabric. The defaults are a realistic case, so you can change one value at a time and watch what moves.
2. There is no calculate button. Every figure recalculates as you type or drag, which is what makes this usable for a what-if sweep rather than a single answer.
3. Read Fabric to Buy in the dark results panel — that is the headline figure, expressed in m².
4. Check the supporting rows underneath (Ridge Height, Roof Slope Length incl. Valance, Roof (Two Slopes), Gable Ends (Two Triangles), Side & End Walls, Fabric in the Cover Set, Cover Set Mass and Floor Area) before acting on the headline — they are where an implausible input usually shows itself first.
5. Reset to defaults returns every field to the reference case, which is the quickest way to check whether a surprising result came from the tool or from an input you had changed earlier.

Where this is used

• Process planning — establishing Fabric to Buy before a trial is booked, so machine time and material in Leather, Coated Fabrics & Tarpaulins are committed against a calculated figure rather than an estimate.
• Costing and quotation — Fabric to Buy is an input to the cost sheet, and quoting from a worked number rather than a remembered one is what keeps a margin intact.
• Troubleshooting — when the floor result drifts from plan, entering the measured values (starting with Marquee Length) shows how much of the gap in Fabric to Buy each variable explains.
• Teaching and study — the accepted ranges bracket normal Leather, Coated Fabrics & Tarpaulins practice, so moving one variable at a time shows the shape of the relationship rather than a single answer.

Reading the result

Typical bands and what each one is telling you.

Assumptions and limits

• The frame is a simple gable: two roof slopes meeting at a ridge along the length, triangular gables above each end wall, and walls round all four sides from the ground to the eaves. Doors and windows are counted as wall fabric; clear window film, zips and the keder or rope edges are extra. The seams allowance covers welded overlaps and hems as a share of the net area. Mass is the fabric bought at its weight per square metre. Hexagonal, pagoda and clear-span structures need their own geometry. **This is a fabric take-off; wind and snow loads, anchoring and the frame are the structure maker's and the event engineer's.**
• Every input is bounded to the range normal practice occupies (Marquee Length 1 to 200 m, Span (Width) 1 to 60 m and Leg (Eave) Height 1 to 10 m, and so on for the rest). Those bounds are guard rails against typing errors, not a claim that the formula fails one unit outside them.
• The calculation is deterministic: the same inputs always give the same result. It carries no allowance for machine condition, operator skill, ambient conditions or lot-to-lot material variation unless an input above explicitly represents one.
• Nothing is sent anywhere. The maths runs in your browser, so the numbers you type never leave the page.

Standards and further reading

• EN 13782, Temporary structures, tents, safety: design, installation and use of tents and marquees.
• Fire rules for tent fabrics where the marquee is used, for example NFPA 701 in the USA or EN 13501-1 classification in Europe.

Questions people ask