Here’s a simple trick to get square downspouts to do and go where you want.
I was recently tasked with installing 2-1/2″ square aluminum downspout on a flat roof that has round copper scuppers poking down through the soffit. One of the downspouts also had to transit back to the house wall at a 45 degree angle, as it is at a corner of a 2′ overhang. This is not a natural task for materials meant to attach at right angles.
After struggling with trying to squeeze the square peg into a round hole, I decided to try a more methodical approach. I had a leftover copper scupper and decided to use it as a form. By squeezing the downspout around the scupper pipe with a hose clamp, I found that I could easily re-shape the square downspout ends to round, making them not only attach to the scupper neatly but also conform to the angle required to reach the wall.
