How To Work Out Flat Roof Percentage

Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m.

How to work out flat roof percentage. Let s say it is equal to 1 5 m. Pitch rise run 1 5 6 25. Calculate the roof pitch as the proportion of rise and run. Pitch measurement method 1.

The most precise way to find the roof s slope is by measuring it from the underside. Hold the 0 mark of the tape measure against the roof. 8 inches and you have an 8 in 12 pitch. I just want to check how this is calculated.

Calculate the rafter length substituting these values into the following formula. Measure the vertical distance from roof to level. Here s what i did. Measure the rise of your roof.

For ground snow loads greater than 20 pounds per square foot the roof load is equal to 70 of the product of the exposure thermal and importance factors the ground snow load and 20 pounds. A policy we wish to take out specifies that we can have a percentage of the roof as a flat roof at no more than 25. Locate the level s 12 inch mark. On a ladder beside the roof place the level a foot or so up the roof hold it level and measure from the 12 inch mark on the level s bottom straight down to the roof.

I ve checked the room dimensions up and down left and right and i can t get anywhere near the threshold but i m nervous. Use a level against the underside of the rafter you re measuring to get the most accurate value. How to work out slope percentage if we want to work out the percentage of a slope you first must ensure you convert the units so they are the same similar to working with the ratios above. If you have any concerns as you are determining your flat roof snow load consult with a structural engineer or roofing specialist.

Access one of the rafters then take the measurement this way. Extend it upward so it is perpendicular to the level.