Gutter Sizing Smacna

The smacna series gutter system is an exceptionally strong gutter product for industrial commercial type buildings.

Gutter sizing smacna.

News smacna s downspout and gutter sizing calculator one of the most frequently asked architectural questions smacna receives is on sizing gutters and downspouts. Downspouts should be constructed with conductor heads every 40 ft 12 2 m to admit air and prevent vacuum. If a roof s various drainage areas call for different size gutters go for the biggest one k style. 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. 6 inch 7 960 square feet. 5 inch 5 520 square feet. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.

The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website. Saf smacna gutters are an extension of the saf industrial series gutters but with profile features contained in the sheet metal and air conditioning contractors national association smacna manual all styles are supplied in a standard 6 size and are. Then use the chart below to see what size gutter you need. 5 inch 5 520 square feet.

Calculations are based on level gutter capacity as experimentally determined by the national institute of standards and technology nist. The size of the downspout should be constant through out its length. This tool allows engineers architects designers and contractors to easily and accurately size downspout and gutters per smacna s architectural sheet metal manual. Downspout sizes must not exceed the bottom width of the gutter.

The sheet metal and air conditioning contractors national association smacna is an international trade association representing 3 500 contributing contractor firms. If a roof s various drainage areas call for different size gutters go for the biggest one k style. To limit the effects of thermal expansion in gutters 50 ft. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.

15 m is a practical maximum gutter length to be served by a downspout. 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. Then use the information below to see what size gutter you need. Offset of more than 10 ft 3 0 m can affect drainage capacity.

Smacna notes that one of the most frequently asked architectural questions the association receives is about sizing gutters and.