Proper gutter and downspout sizing rainfall intensity downspout capacity rainfall intensity is usually given in inches per hour for a five minute duration or one hour duration based on u s.
Smacna gutter styles.
Downspout sizes must not exceed the bottom width of the gutter.
Custom profiles are also available.
Sheet metal and air conditioning contractors national association 4201 lafayette center drive chantilly virginia 20151 1219 tel 703 803 2980 fax 703 803 3732.
Every gutter system is unique so saf smacna gutter profiles are custom fabricated to suit individual project needs.
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.
They are available in a number of different styles including double bead single bead and reverse bead style.
All styles are supplied in a standard 6 size and are manufactured in 10 lengths with a heavy duty 125 aluminum interior strap.
6 inch 7 960 square feet.
Dynaclad 70 full strength pvdf paint finish natural copper rheinzink or stainless steel.
Optional support brackets also available.
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.
5 inch 5 520 square feet.
Choice of over 32 colors for galvalume and aluminum.
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.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
New orleans los angeles for example.
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.
Optional support brackets also available.
15 m is a practical maximum gutter length to be served by a downspout.
Dmi offers our box gutter in six standard smacna profiles see profiles tab below.
These differences will not affect how well the gutter performs or how difficult it is to install on your home but are all a matter of personal preference as to the appearance.
Then use the chart below to see what size gutter you need.
Available in up to 32 0 lengths.
Table 1 2 based on records through 1978 gives five minute intensities for selected cities.
Calculations are based on level gutter capacity as experimentally determined by the national institute of standards and technology nist.
