Proper Roof Slope For Rain

Measure the length of the string to determine the distance between the two points.

Proper roof slope for rain.

The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. This means that your gutter should be a half inch lower in height at every 10 foot mark until you reach the downspout. If you have 30 feet of guttering as above you know the slope should be 3 4 of an inch. The pitch of your roof also helps determine the type of materials that can be used on your roofing system.

A wide roof with a steep slope will lead to faster runoff hence necessitating a slightly steeper slope for effective discharge of the rain water. To put it in perspective the angle of this slope would be around 30 degrees. The roof pitch would be described as a 6 12 pitch. The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches.

Divide the results by the number of 12 inch segments in your level. Roofs at the lower end of the range about 4 12 to 6 12 are relatively easy to walk and work on. The primary reason roof pitch exists in the first place is to redirect water. A handy roof slope estimator can help you determine if your roof slope is likely too low for shingles.

For example if you used a 24 inch level and your measurement was 12 inches the pitch in your roof is 6 in 12. For spans longer than 40 feet it s wise to have a downspout on each end and start the high spot of the gutter in the center. A small roof with a shorter length on the other hand will not collect a lot of water within a short period of time and will work just fine with the minimum roof slope for drainage. The majority of north american residential roofs have historically been constructed with a slope between about 4 12 and 9 12.

At that point measure down from the exposed butt end back to the roof surface. For gutter runs longer than 40 feet it s best to pitch the gutter down from the middle to a downspout at each end. It is an essential element to ensure water drains properly off of your roof. This means that the rise of the slope goes up or down 8 inches for every 12 inches.

Use a string level to ensure the string is completely parallel to the ground. However you can only use this pitch with built up roofing or specialized synthetic roofing. Or you can slope the gutters down from each end toward a single downspout placed in the middle of the run. Take the downspout end of the string lower it 3 4 of an inch and reattach it.