scuppers and the need for conductor heads
Greetings, could anyone comment on the need for conductor heads for scuppers ? In a cold climate, will scuppers plumbed directly to a pvc 90 and a pvc down spout work ? The conductor heads and downspouts are located outside the brick walls, but inside the steel studs and tin exterior- added later. Any advice would be greatly appreciated. Thanks
Are you saying that there are existing conductor heads and downspouts that are hidden behind metal panel siding? This isn't optimal, you should be able to see these components, especially in a cold climate, in case they become blocked due to debris or ice and you need to clean or repair them.
To answer your question:
Generally, you want to keep the scupper separate from the downspout to allow for differential movement between the components (avoiding stress damage) and to allow for water overflow at the top of the downspout in case the downspout gets clogged.
If the downspouts are connected directly to the scuppers, you run the risk of water backing up and pooling on the roof itself if there's a clog. If they are separated, the water will still drain off the roof even if the downspout is clogged.
Normally you would then be able to see that there's a clog (because of the overflowing water) and get it fixed.
So you want to keep the scupper and the downspout physically separated to minimize the risk of overloading the roof with water.
You need a conductor head in this normal construction method in order to catch all the water coming out of the scupper and act as a funnel to direct the water into the downspout, which normally has a much smaller diameter than the scupper.
Hope this helps and let me know if you have further questions!