How to Figure the Slope on a Porch

Although a porch is supposed to be level, there are multiple sloping surfaces that may be part of the porch structure. These sloping surfaces include the roof and any types of ramps leading up to the porch. If you need to figure out the slope of a porch's roof or ramp, you will need to utilize a common mathematical formula known as "rise over run." This formula uses measurements to describe the degree to which a slope rises as it extends, or "runs," across a specific distance.

Tape measure
Ladder
Level

Instructions

- 1
  Measure the length of the roof or the ramp from its edge to the porch. This is the run. For instance, you might have a ramp that is 8 feet long from its end to the edge of the porch.
- 2
  Calculate the height of the ramp or roof. If you are measuring a ramp, you will need to measure the height of the ramp from its highest point -- where it connects with the porch -- to the ground. For a roof, you will first need to climb a ladder that gives you access to the roof. Hold a level at the tallest point of the roof's slope in relation to the porch -- the point where the porch connects to the house. Drop a tape measure downward from this point and take note of the measurement that coincides with the bottom of the roof.
- 3
  Divide the height of the ramp or roof by its length in order to find the slope. This is equal to the "rise" divided by the "run." For example, if a ramp is 8 feet long and 2 feet high, you would divide 2 by 8 to get 1/4 or 0.25.

How to Restore a Rusted Metal Door

How to Replace Bricks on a Front Porch

Exterior Home Repair