Can someone please explain the difference in these pictures?? I understand chimney height requirements but am confused about fuel vents and flue pipes minimum height.
One picture shows 3 feet, one says 2 feet, and the chart shows 1 foot.
Also chapter 3 of the inspecting roofing course says “It is a common mistake to apply chimney termination-height requirements (3-2-10 rule) to fuel vents, which cause vents to extend above roofs much higher than needed.” The rules seems conflicting. Any help would be appreciated.
Yes. Confusing at first but makes sense somewhat.
MASONRY chimneys have the 3-2 -10 rule
WOOD burning metal flues also have the same rule
B VENT - aka double wall metal flue for gas appliances (boilers etc) actually have 2 rules based on that last table foto. There are 2 tables based on width if the B vent used. I am on my phone , i will try and post both tables later on or if someone else can do it for me beforehand.
It comes down to 3 different types of ‘chimneys’ having their own rules
Vent caps larger than 12" must be located at least 2 feet above the highest point and 2 feet higher than any portion of the building within a horizontal distance of 10 feet.
Vent caps 12" and smaller may terminate a distance above the roof if 8 feet or more away from a vertical surface as your table shows
