Unequal Sloped Roofs

Using a tape measure make a pencil mark 12 inches from the end of a carpenter s level.

Unequal sloped roofs. This slope and skew calculator makes it easy by performing all of the necessary trigonometry for each hanger condition in the roof. The rafter tools app irregular hip rafter function calculates the correct king common rafter length for unequal pitched hip rafter roofs. Simply locate a roof rafter board place the end of the level against the bottom edge and measure from the 12 inch mark vertically to the bottom edge of the rafter. Major pitch angle minor pitch angle minor run calculate.

The correct way to calculate the minor pitch king common rafter keeping all of the roof framing members in the roof planes is to use the major and minor plan angles. The formulas below use the law of sines to calculate the unknown length or angle. Drawing a superimposes the common rafters for the two roof pitches and illustrates the problem that occurs when roof layout starts at the outside edge of the exterior walls. Where roofs of unequal pitch join it requires careful layout to create equalwidth soffits with equal height fascias.

Create a roof slope using slope arrows. Major pitch angle minor pitch angle major run calculate minor run minor run major run tan major pitch angle tan minor pitch angle minor run major run major pitch minor pitch known variables. Put on a pair of work gloves. Unequal pitch roof trigonometry calculating unequal pitched roofs is easy if you know what trigonometry functions to use.

It is advisable to prepare a framing plan as shown in fig. 9 tips to understand revit roofs. Then you ll be able to measure slope from an unfinished attic space under the roof. The formulas below use the law of sines to calculate the unknown length or angle.