Smacna Gutter Sizing

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.

Smacna gutter sizing. Offset of more than 10 ft 3 0 m can affect drainage capacity. In response smacna s technical resources department has created a free downspout and gutter sizing calculator. Smacna s new downspout and gutter sizing calculator enables the user to manually enter the design area of the roof or use the design area wizard for the calculation. This application runs the equations laid out in the smacna handbook.

The gutter outlet capacity should suit the downspout capacity. In response smacna s technical resources department has created a free downspout and gutter sizing calculator. Downspouts should be constructed with conductor heads every 40 ft 12 2 m to admit air and prevent vacuum. 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. It should be used to calculate required gutter size downspout size and downspout spacing for a given roof area. 15 m is a practical maximum gutter length to be served by a downspout. 6 inch 7 960 square feet.

5 inch 5 520 square feet. 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 revised round industrial duct construction standards 3rd edition 2013 an american national standard ansi smacna 005 2013 is. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.

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. If a roof s various drainage areas call for different size gutters go for the biggest one k style. Gutter sizing per smacna. News round industrial duct construction standards 3rd edition now available.

Then use the chart below to see what size gutter you need. 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. For additional information please see below. The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website.

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