I have a range that is located against an outside brick wall in a one-story kitchen with a flat roof. To avoid going through the brick wall, can I vent the hood straight up through roof? What sort of cap would I use that would prevent insects from entering but would still operate properly in a strong wind or with a heavy snow load? -John
Yes, you can vent a range hood through the roof using a 6” single wall pipe.
You can buy the proper flashing to install it on a flat roof and a roof cap that has screen around it to prevent insects from entering.
Be sure to extend the pipe up at least 2’ to 3’ above the roof to prevent snow buildup from causing problems.