Flat Porch Roof Pitch Standards

Anything less than one eighth of an inch may pool on the roof.

Flat porch roof pitch standards. You will need to ensure that you are in standards with your local building codes and have the permits required. The flat roof already has a slight pitch as it is required by law. The most commonly used roof pitches fall in a range between 4 12 and 9 12. If you have a flat roof shed or porch you ll need to be sure it has adequate pitch or you could find yourself having to conduct frequent roof repairs due to poor drainage.

Low pitched roofs are generally difficult to maintain and you need special materials to prevent leaks. Measure 12 inches from the bottom of the level and mark the spot on your house. On a ladder tall enough to reach the end of your roof put the level against the house parallel to the ground where the roof meets the house. Most people view pitching a flat roof as a tedious job.

However you can only use this pitch with built up roofing or specialized synthetic roofing. Porch roofs come in different forms and styles thus taking the shape of the roof. Pitches of less than 2 12 are considered flat roofs even though they may be very slightly angled. Sunday august 5 2018 the traditional metal roof types such as 5v crimp shown above and corrugated are rated by the manufacturers for use down to a 3 12 pitch three inches of vertical rise for every foot of horizontal run.

Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs. The same self healing characteristic restricts the use of coal tar pitch to roof systems of little or no slope typically 1 8 of an inch per foot or less. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. This is suited for large buildings and houses wherein this would make them appear more attractive and also works in maximizing the space.

Coal tar pitch is derived from coal distillation and should not be confused with roofing asphalt which is a product of crude oil refining. Flat roofs which aren t perfectly flat require a small slope to allow for water runoff. Then measure from the spot created vertically to the roof. Pitches above 9 12 are very highly angled and are designated steep slope roofs.

This is the number needed for the pitch calculation. Generally such roofs have a pitch ranging from 1 2 12 to 2 12.