To derive formulas for the critical angles we need to define some terms which i do in figure 2.
Roof sheathng do you angle the edges at hips valleys.
The two shorter legs of this triangle are each equal to the total run of a.
Purlin lip cut angle 11 4.
Hip valley side cut angles.
This video shows how some roofs fail under heavy winds in uplift situations.
The edge bevel of the valley sleeper can be found from using geometry.
You can see from the plan that the total run of a hip rafter is the hypotenuse of a right triangle.
Over driving nails is always a.
You only use the hip rafter backing angle to edge bevel hip valley rafters.
On a hip roof framing plan the lines that indicate the hip rafters ec ac kg and ig in figure 18 3 form 45 angles with the edges of the building.
Cut the plywood for that hip or valley in advance.
It helps support this site.
Angles at the hip rafter foot are located at the valley rafter ridge those at the hip rafter peak are at the valley rafter foot.
The connection between the roof sheathing and the structure is a vulnerable point that is known to fail during a hurricane.
You can use a straight edge to achieve a straight cut.
Hip valley rafters are backed out to align with the roof planes.
Outside top plate edge to ridge top edge common 10 11 3 4.
Hip roof framing center join diagram with options for square roof 1.
Keep these tips in mind when roofing in hurricane areas.
Nail down each valley shingle at least two inches 50 mm back from the chalk line.
Hip backing angle 15 4.
When you reach the valley lay the shingles over the valley and trim the edges to the chalk line.
Measured from the hip roof eave to the hip ridgeline.
The dihedral angle triangle for the hip valley rafter backing angles is perpendicular to the hip valley rafter in elevation.
How to figure the difference between the short point and the long point when cutting plywood for a hip and valley roof.
Here s a little trick to amaze your coworkers.
Or you can use trigonometry.
With a square roof the ridge becomes a square center piece kingpost with side lengths equal to common rafter thickness.
Using these angle definitions i will derive formulas for the sheathing θ s and hip pitch angle θ h given the common pitch angle which i call the roof pitch θ r and plan angle θ p.
From drip edge to valley flashing december 25 2018 drip edge metal valley flashing dormer chimney and kick out flashing shed water away from the connections between roofs walls chimneys and other building assemblies.
Roof sheathing angle arctan tan 45 cos 26 56505 48 18968 arctan tan 45 cos 26 56505 valley sleeper miter angle at the top of the sleeper jack rafter side cut angle 41 81031.
During a hurricane the strength of the sheathing on the roof can greatly impact the homes ability to weather the storm.
But first consider buying my book the roof framers field manual.