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PLAN THE SHAPE. UNDERSTAND THE TRADEOFFS.
A better fit, one panel at a time.
CROSS SECTION
Circular roof
Build it in modules
KNOW YOUR SHAPE
A wall-top tension tie crosses the interior at the wall height. It is an obstruction even where the roof is taller.
GEOMETRY, NOT A LOAD RATING
Compare the roof’s outward push
Apply the same uniform vertical pressure and load-strip width to every shape. Each roof uses the same remaining length of its bent panel. Raised mode uses separate panels for the lower walls.
Pressure is a what-if input, not a local snow-load recommendation. Load-strip width is independent of panel width and post spacing.
Mesh reference: Tractor Supply Max 50, item 3502077; OKBRAND 0060-0 spacing table (checked September 26, 2026). Ten line wires over 50 in: two 4-in gaps followed by seven 6-in gaps; cross wires every 8 in along 192 in. The drawing assumes tight rows at the bottom of each wall panel and toward the front edge of every roof panel. Overlaps retain both wire patterns; coincident wires share a line. Custom panel widths show an envelope without product mesh. Wire thickness is illustrative.
| Roof | Rise | Span | Headroom width | Outward thrust / side | Peak |M| |
|---|
* Rise adjusted to the nearest valid value for that family. Different spans collect different total loads at the same pressure. Peak |M| is an idealized bending demand in lb·ft, not a strength score.
Without a tension tie
THE ROOF-ONLY ANALOGY
q = pressure (psf) · s = load-strip width (ft)
B = span (ft) · f = roof rise (ft)
Three hinges: two at wall tops and one at the crown. The actual panel and T-post assembly is not this idealized structure. Raised wall joints and their supports require separate design.
Assumptions, limits & references
For the idealized roof, each vertical reaction is q·s·B/2. At distance x from the left springing, M(x) = q·s·x·(B−x)/2 − H·y(x), with y measured above the wall top. A parabola has zero bending only for this specific uniform projected vertical load.
This model excludes panel stiffness, weld strength, buckling, plastic bends, connection slip, T-post bending, soil resistance, uplift, unbalanced snow, wind, bracing and load combinations. Wire ties are assembly fasteners; no structural capacity is assigned to them. Faceted corners require moment continuity in this analogy.
Load capacity stays unknown until suitable material data, connection/anchor design and a validated structural model or testing are available. Geometry follows the panel centerline and does not subtract covering or wire thickness. Tight bends and slope changes may require supports and may damage welds.
Reference: Felix Udoeyo, Structural Analysis: Arches and Cables. Weather context: University of Minnesota Extension: snow and ice roof collapses.
From dimensions to a repeatable shape
The guide follows your current design. Download an offline HTML sheet to keep or print; Print plan also includes these instructions.
EDITABLE SHOPPING ESTIMATE
Materials for this design
Prices in USD. Edit quantities or unit prices to adjust your budget. Custom quantities stay fixed when the design changes; Use calculated restores automatic updates. Excluded covering and tension items stay out of the total until enabled. This is a budget, not an engineered bill of materials.
| Material | Quantity | Unit price | Total |
|---|
Excludes labor, delivery, doors, tools, braces, ground anchors, ridge supports and site preparation. T-post count is a layout allowance, not a verified support spacing. Whole-tarp mode tiles the developed surface with 6-in joins, applies the area allowance equally to both dimensions, and budgets separate sheets for each end. Verify finished size, seams and the cutting plan. Square-foot mode is an area allowance only. Tension tie stock and fittings remain unverified budget prices.
Tractor Supply product snapshot · September 26, 2026
Panel, post, wire-tie and tarp pages were checked with Greenwood, SC · 29646 selected. The added clip price was checked separately with Grassland (Franklin), TN selected. Neither location has been confirmed by you. Prices and stock can change; this is a dated snapshot, not a live feed.
Alternative: 16-gauge rebar wire, 3.5-lb roll is listed at $9.99 in the indexed product page. Live local price was not checked. Roll-length entries conflict (10 ft versus about 330 ft in Q&A), so it is not used for automatic quantities. No structural tension-tie product is selected.