Downspouts are one of the major parts of their gutter project that homeowners neglect. Even those who do a fair amount of research rarely understand that there are differences in the gauge of their downspouts. Unfortunately, most contractors will neglect to inform their customers what gauge they are using because of thinner, inferior products. Some contractors will advertise that they use .032 gauge gutters and just leave it to the customer to assume that the downspout is the same gauge — it is not.
There are three gauges that are used for corrugated aluminum downspouts:
(1) .016 is the thinnest that is commercially available in many big box stores
(2) .019 is widely available to good contractors who offer customer colors
(3) .024 is the thickest gauge available in customer colors. Unfortunately, it is not available in all areas.
All three downspouts mentioned above are corrugated. These extra bends help to strengthen your downspout and also explain why manufacturers don’t feel they need to provide downspouts that are as thick as the gutters themselves. Still, if a contractor cannot tell you what thickness downspout they are using, chances are that it’s the thinnest and cheapest available. Here’s a tool that measures the thickness of aluminum.
The only time when a homeowner could neglect the gauge is if they have a zero percent chance of being bumped or jarred by children, pets, or wildlife. At the same time, it makes sense to plan for contingencies, and homeowners who choose the lightest gauge will likely have to have repaired at some time in the future.
Jim McGuigan is a contractor residing in Brown Deer, Wisconsin. His work on gutters, floodwater management, and water hydrology projects has helped thousands of homeowners in Southeastern Wisconsin.