Standard Roof Gutter Sizes

If a roof s various drainage areas call for different size gutters go for the biggest one k style.

Standard roof gutter sizes.

Furthermore the standard norm for gutters among many in the rain carrying industry is to allow 1 square inch of outlet opening in the gutter for every. When you are completing a gutter replacement the first point to note is that gutters come in different sizes. Then use the chart below to see what size gutter you need. Welcome to gutter supply your online reference for gutters gutter machines gutter guards and accessories.

Downspout sizes are based on table 1 3 dimensions of standard downspouts page 1 4 of the architectural sheet metal manual 7th edition. The steeper a roof s pitch the more windblown rain it can collect. 5 inch 5 520 square feet. 6 inch 7 960 square feet.

Hold one end of the level against the roof level it and then measure the distance between the roof and the underside of the level at its midpoint which. Simplified suitable for flattish roofs with little or no vertical faces or steep roofs draining to one side of box gutter only or any roof if you are in a hurry and make the necessary allowances for all catchments. Downspout sizes must not exceed the bottom width of the gutter. Roof pitch is very important for right roof gutter sizing.

Box gutter with rain water head at end of box gutter. Downspouts also come in different sizes such as 2 3 inches and 3 4 inches in size. 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. Come visit our selection of quality products.

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. Outlet sizing and spacing your gutter system will perform its best when a proper outlet size is chosen to drain a given roof area. Downspout sizes must not exceed the bottom width of the gutter.

5 inch 5 520 square feet. If you are worried you will need a larger gutter than the standard 6 inch it s important to talk to your roofer about your maximum rainfall intensity the pitch of your roof and the drainage area square footage. You can measure pitch with a 2 foot level and a tape measure. Then use the information below to see what size gutter you need.

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.