How To Match A Roof Jack Angle To Roof Slope

Certain roof slopes are safe enough to walk on without using roof jacks.

How to match a roof jack angle to roof slope.

Roof slope calculator example of use. Since there are various angles of roofs it is important to use a roofing jack according to the angle or pitch of the roof. It is also necessary to select the pitch of the complimentary roof. The minimum pitch for a standing seam metal roof is 1 4 or 3 inches rise to 12 inches run.

A 2 4 rafter just doesn t leave enough height after the birds mouth to match on any roof pitch. So if your roof is a 45 degree angle that is for every 12 along the horizontal run it rises 12 it s a 12 12 pitch. If you re using a roofing calculator press the pitch button to input the pitch ratio in the calculator s memory. The traditional method has been rise inches 12 run inches.

Most of the times it is the same as the pitch the jack rafter is on. And angles back against the top chord of the truss. The top chord smoothly extends out past the wall to create the overhang. Next select a the pitch the jack rafter is on.

What angle should a porch roof be. Roof pitch is measured in a rise to run ratio with the vertical rise always shown first. Also measure the length of half of the roof from one side of the ridge beam to the edge of the building. Where the porch roof extended over the shed roof we installed a 2x6 ridge that ran from the top of the dropped structural ridge to the apex of the sleepers.

This is exactly the same ratio as the pitch for the other side but i find it helps to work the two sides separately to avoid confusion especially when it comes to laying out the jack rafters. With the roof pitch the same. To scribe the angle we placed a length of stock on top of the rafter peaks and leveled it across using a scrap block to trace the angle. Of course there are old homes which have an outstanding pitch of around 8 12 and above.

This is the adjacent roof that will share the hip or valley. Most roof jacks depend on angles. Pitch tan angle where angle is the roof pitch expressed in degrees. If it is not the same it does not matter to this calculator.

Match roof material and use appropriate slope. If the roof truss has a 2 4 top chord. Standard roofs are around 3 12 to 6 12 pitches. The value displayed as the rise will be your x.

Walking on a roof with a pitch of 5 12 or 6 12 is possible but it is still a good idea to place a row of roof jacks along the bottom edge of the roof. The minimum pitch for shingles is 1 6 which is equivalent to 4 inches rise to 24 inches run. For a slope of 4 12 four inches of rise to 12 inches of horizontal run roof jacks are probably not needed. If it rises only 6 for every 12 it s a 6 12 pitch.

Determine the minimum slope of the roof based on the roofing material. If you want to find the roof pitch in the form of x 12 simply calculate the pitch and substitute 12 for the run length.