Framing A Pentagon Roof

You would use the pitch of the polygon roof on the tongue of the framing square and the hip run per foot on the blade of the framing square to layout the plumb and level cuts for the polygon hip rafter.

Framing a pentagon roof.

The slate roof was nailed to a wood sheathing that covered concrete at a 23 degree slope. 1 8 pitch is given so 24 x 1 8 equals 3 or unit of rise in inches. The framing of a basic gable roof is based on a right angle triangle and the various roof framing components fit the triangle. Then i start building the base.

And the line length measurement from the roof peak to the building wall is the hypotenuse. Then the tongue will give the direction of one side of the triangle. Place the square so that 12 inches an the tongue and 20 79 inches on the body are over the line a b. Or they could have purchased a chappell master framing square that has the hexagon and octagon roof framing information printed on the square.

By reversing the square so that the 12 inches is at a and the 20 79 inches is at b the other side of the triangle may be drawn. In this video jerry cole of in line industries shows how simple it can be by building a 5 sided pentagon frame in less than 10 minutes and cuts it to a perfect size the first time. The rise or height of the roof at its peak is the altitude of the triangle. This model is just to show that framing a 5 sided pentagonal roof is possible and what the rafters would look like digital jobsite facet gazeebo hip model and measure pentagon pentagonal pitch rafter roof slope tutorial.

The slate roof which did its job protecting the building from water actually. The rafters on the roof side of the turret are cut flush with the plate. 6 159 on the tongue and 10 on the body to draw out the plumb and level cuts of the octagon hip rafter. If the unit of rise in inches is 3 then the cut is the unit of rise and the unit of run 12 inches or 3 12.

A hip roof design refers to a roof where the roof sides slope downwards from a middle peak with the rafter ends meeting the exterior walls of the house. Figure 2 2 roof framing terms. After drawing the plan and figuring out the various framing lengths and angles i pick the best stock for one common rafter to use as a pattern for the rest. Plan first cut rafters then assemble the base.

Apothem multiplier can be used to find the hip rafter run of the polygon if you know the common rafter run. Each of the four sides of the roof slope downward there are no upright or vertical parts no gables etc on a hip roof. When flight 77 hit the pentagon on september 11 2001 it dumped jet fuel on the roof that then ignited. The run or half the building span is the base of the triangle.