Roof Water Gutter Calculator

This means the downspout end of the gutter should be set 3 4 of an inch lower than the other end.

Roof water gutter calculator.

That part of the gutter in which the angle obstructs the flow. Divide the inch per hour watershed of the roof by the 5 minute rainfall intensity. For example if you have 30 feet of guttering the calculation is 1 4 x 3 0 75 i e. To limit the effects of thermal expansion in gutters 50 ft.

The code limit is 150mm for dp s and 26 800 sq mm for flat eaves gutters the program will calculate the size and number of downpipes downspouts leaders required and the eaves gutter sizes for any roof. Roof drainage layout and calculations. Calculations are based on level gutter capacity as experimentally determined by the national institute of standards and technology nist. Now architects engineers designers and contractors can easily and accurately size downspouts and gutters according to the specifications in smacna s architectural sheet metal manual 7th edition 2012.

So for a roof that is 5 m long with a height of 4 m and the roof width is 8 m which makes the half roof width 4m we can calculate the effective roof area like this. Ask gutter suppliers what size gutters will be needed to handle that amount. 3 select gutter type. The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website.

Calculate effective maximum roof area b c 2 x length of roof area in m installation. As a general rule gutter slope is set at 1 4 inch per 10 feet of guttering. 2 count the number of downspouts drain pipes on your house building and enter the number in downspouts field. The tools guide the user step by step allowing fast and simple roof drainage design whilst ensuring full compliance with bs en12056 3 rainwater drainage design standard.

Calculate the area of a roof to work out how much guttering is required. Downspout sizes must not exceed the bottom width of the gutter. Simplified suitable for flattish roofs with little or no vertical faces or steep roofs draining to one side of box gutter only or any roof if you are in a hurry and make the necessary allowances for all catchments. That will show how much water a gutter will have to drain.

Refer to bsen 12056 part 3. How to use the calculator 1 measure the length of your gutters along the eaves of your roof and plug in the number in the length field. Box gutter with rain water head at end of box gutter. 15 m is a practical maximum gutter length to be served by a downspout.

Measure the length of the gutter for downspout locations. There is no limit to downpipe size or eaves gutter size. Roof drainage calculators our online tools have been designed with simplicity in mind removing the need for any prior specialist industry knowledge.