Pitch Rate For Gutters

Gutters should be placed below the extended roof line so that snow and ice can slide clear.

Pitch rate for gutters.

This means the downspout end of the gutter should be set 3 4 of an inch lower than the other end. Multiply the number of feet by 1 16 inch to determine the total slope the gutter requires. The steeper a roof s pitch the more windblown rain it can collect. For example if you have 30 feet of guttering the calculation is 1 4 x 3 0 75 i e.

A steeper pitch will make water run down faster and require an oversized gutter. Increasing the pitch increases a gutter s handling capacity but the gutter may look askew over a long run. For example for every 10 feet of gutter they need to drop 1 2 inch from the high end to the downspout. I have never had an issue with this as for mud and sludge build up it makes no difference it dont move inside the gutter.

Steeper pitches require less clearance. This allows the water to flow gently but. These rates correspond to 0 133 in min 3 4 mm min and 0 08 in min 2 mm min. Metal roofs also shed water at a much quicker rate than an asphalt roof therefore we always recommend 6 gutters to handle the faster runoff of the water.

Local codes may require that drainage systems only be designed for the latter. For example if the gutter is 16 feet long the end near the down spout must be 1 inch lower than the starting end. It takes 96 15 square feet 8 93 square meters of surface with 1 inch per hour 25 mm hr of water to correspond with 1 gpm 0 063 l s flow rate. My gutter installer keeps them close to level unless something above dumps into it.

Increase the pitch of the gutter. The standard is about inch per 10 feet. As a general rule gutter slope is set at 1 4 inch per 10 feet of guttering. In my opinion some pitch is good i d say 1 8 per ft.

Roof pitch is very important for right roof gutter sizing. Hold one end of the level against the roof level it and then measure the distance between the roof and the underside of the level at its midpoint which gives you a 12 inch run. Gutters need to be pitched at a 5 degree angle. Many of today s newer homes have more complex roof lines.

Gutter can be run level for appearance but addition downspout will be necessary see section on proper gutter and downspout sizing.