Gutter Sizing Smacna

5 inch 5 520 square feet.

Gutter sizing smacna.

The smacna series gutter system is an exceptionally strong gutter product for industrial commercial type buildings. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. News smacna s downspout and gutter sizing calculator one of the most frequently asked architectural questions smacna receives is on sizing gutters and downspouts. 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. Downspout sizes must not exceed the bottom width of the gutter. 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.

Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. 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. Calculations are based on level gutter capacity as experimentally determined by the national institute of standards and technology nist. Smacna notes that one of the most frequently asked architectural questions the association receives is about sizing gutters and.

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. 5 inch 5 520 square feet. The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website. Smacna downspout and gutter sizing calculator.

Then use the information below to see what size gutter you need. Then use the chart below to see what size gutter you need. To limit the effects of thermal expansion in gutters 50 ft. 15 m is a practical maximum gutter length to be served by a downspout.

The sheet metal and air conditioning contractors national association smacna is now providing a simple and effective downspout gutter sizing calculator. The sheet metal and air conditioning contractors national association smacna is an international trade association representing 3 500 contributing contractor firms. Offset of more than 10 ft 3 0 m can affect drainage capacity. 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.