Smacna Gutter Sizing

Downspouts should be constructed with conductor heads every 40 ft 12 2 m to admit air and prevent vacuum.

Smacna gutter sizing.

6 inch 7 960 square feet. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. 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. To limit the effects of thermal expansion in gutters 50 ft.

Gutter sizing per smacna. This application runs the equations laid out in the smacna handbook. In response smacna s technical resources department has created a free downspout and gutter sizing calculator. 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.

In response smacna s technical resources department has created a free downspout and gutter sizing calculator. 15 m is a practical maximum gutter length to be served by a downspout. For additional information please see below. The sheet metal and air conditioning contractors national association smacna is now providing a simple and effective downspout gutter sizing calculator.

In response smacna s technical resources department has created a free downspout and gutter sizing calculator. The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website. If a roof s various drainage areas call for different size gutters go for the biggest one k style. 5 inch 5 520 square feet.

News round industrial duct construction standards 3rd edition now available. The size of the downspout should be constant through out its length. The gutter outlet capacity should suit the downspout 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.

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. Then use the chart below to see what size gutter you need. Offset of more than 10 ft 3 0 m can affect drainage capacity. 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.

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.