Smacna Gutter Sizing

In response smacna s technical resources department has created a free downspout and gutter sizing calculator.

Smacna gutter sizing.

Expansion allowances gutter specific expansion tables based on girth profile metal predicted annual δt expansion of building materials table with various expansion coefficients must be used for fascia and copings with consideration of both metal and substrate flat seam roof expansion guidance over 30 feet use batten seam design to allow for expansion. Offset of more than 10 ft 3 0 m can affect drainage capacity. News smacna s downspout and gutter sizing calculator one of the most frequently asked architectural questions smacna receives is on sizing gutters and downspouts. The capacity of a sloped rectangular gutter may be approximated by using a gutter cross section area not less than that of a semicircular gutter and a depth to width ratio of at least 0 75.

The sheet metal and air conditioning contractors national association smacna is now providing a simple and effective downspout gutter sizing calculator. Gutter sizing per smacna. This tool allows engineers architects designers and contractors to easily and accurately size downspout and gutters per smacna s architectural sheet metal manual. If a roof s various drainage areas call for different size gutters go for the biggest one k style.

Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. For additional information please see below. The size of the downspout should be constant through out its length. In response smacna s technical resources department has created a free downspout and gutter sizing calculator.

6 inch 7 960 square feet. In response smacna s technical resources department has created a free downspout and gutter sizing calculator. News round industrial duct construction standards 3rd edition now available. 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.

The revised round industrial duct construction standards 3rd edition 2013 an american national standard ansi smacna 005 2013 is. 5 inch 5 520 square feet. This application runs the equations laid out in the smacna handbook. The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website.

15 m is a practical maximum gutter length to be served by a downspout. Then use the chart below to see what size gutter you need. To limit the effects of thermal expansion in gutters 50 ft. Downspouts should be constructed with conductor heads every 40 ft 12 2 m to admit air and prevent vacuum.

This wizard makes it easy to calculate the roof design area by providing various shape calculations and the calculation for vertical walls area per international plumbing code ipc.