Framing A Pentagon Roof

The framing of a basic gable roof is based on a right angle triangle and the various roof framing components fit the triangle.

Framing a pentagon roof.

The rafters on the roof side of the turret are cut flush with the plate. 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. The run or half the building span is the base of the triangle. 1 8 pitch is given so 24 x 1 8 equals 3 or unit of rise in inches.

Figure 2 2 roof framing terms. Then the tongue will give the direction of one side of the triangle. Each of the four sides of the roof slope downward there are no upright or vertical parts no gables etc on a hip roof. 6 159 on the tongue and 10 on the body to draw out the plumb and level cuts of the octagon hip rafter.

Line length is the hyptenuse of the triangle whose. And the line length measurement from the roof peak to the building wall is the hypotenuse. However a much of this was destroyed on the fateful day of 9 11. The rise or height of the roof at its peak is the altitude of the triangle.

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. Place the square so that 12 inches an the tongue and 20 79 inches on the body are over the line a b. 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. When flight 77 hit the pentagon on september 11 2001 it dumped jet fuel on the roof that then ignited.

Using the chappell master framing square line 1 under 8 12 6159. 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. 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. Or they could have purchased a chappell master framing square that has the hexagon and octagon roof framing information printed on the square.

Then i start building the base. Apothem multiplier can be used to find the hip rafter run of the polygon if you know the common rafter run. Plan first cut rafters then assemble the base. 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.