Attached Skillion Patio Roof

A wall-attached single-slope patio roof of corrugated roofing on purlins, sloping rafters and a front beam on square steel columns.

Details

Category: Pergolas › Open and Fixed Roof Pergolas

By Huu Khanh Nguyen · Updated November 5, 2026

Parameters

Name	Default	Unit
Roofing panels across	6
Projection	3600	mm
Column height	2400	mm
Purlin spacing	1000	mm
Member width	50	mm
Purlin width	68	mm
Front beam depth	150	mm
Rafter depth	120	mm
Column section	65	mm
Purlin depth	25	mm
Intermediate rafters	2
Columns	3
Frame finish	anodisedNatural
Gutter	true
Gutter width	185	mm
Overall width	(sheetCount * sheetCover) + plateSize - postSize	mm
Overall depth	Math.max(projection + (gutter ? gutterWidth - eaveOverhang : ribHeight * Math.sin(fall * Math.PI / 180)), projection - postSize + postSize + ((plateSize - postSize) / 2))	mm
Overall height	Math.max(deckHeight + ribHeight * Math.cos(fall * Math.PI / 180), (deckHeight + (ribHeight + 1) / Math.cos(fall * Math.PI / 180) - Math.tan(fall * Math.PI / 180) + channelHeight))	mm
Roof fall	5	°
Roofing rib height	16	mm
Roofing cover width	762	mm
Roofing overhang past the beam	50	mm
Rafter top below the beam top	14	mm
Roofing underside height at the wall	(columnHeight + beamDepth - rafterTopDrop + (projection - eaveOverhang - beamWidth) * Math.tan(fall * Math.PI / 180)) + purlinDepth / Math.cos(fall * Math.PI / 180)	mm
Purlin count	Math.ceil((purlinRun - purlinWidth) / purlinSpacing) + 1
Roof finish	steelZincAluminium
Footing plate size	172	mm
Footing plate thickness	8	mm
End cap thickness	3	mm
Back channel height	60	mm
Purlin run	((projection - eaveOverhang - beamWidth) - Math.min(rafterTopDrop, purlinDepth * Math.cos(fall * Math.PI / 180)) * Math.tan(fall * Math.PI / 180)) / Math.cos(fall * Math.PI / 180)	mm
Gutter drop	2 * Math.tan(fall * Math.PI / 180)	mm