Hate to differ Mr. Tyson but its 3 feet measured at the highest spot (roof line )and in vertical 10 and Montreal it 15 feet circumference from building adjacent at 3 and thats the crown ( cement cap ) as some call it,not the top of the liner that should extend another 8 inches to avoid back drafting from crown… the amount of feet at low end may differ greatly .I have built chimneys 4,6,8,10, 12 feet wide with 3, 4, 5, 6 feet deep so again its not that simple to calculate good draft or low spot to 10 foot vertical. As I stated before its more complicated than that 3 in 10 or 15 and many factors to make it draft properly and keep fire safe and draft work properly.I see spark arrestors missing on 70 to 80 percent of chimneys and thats a real no no.
I will try to post more on chimneys, roofing and that witch I am highly practiced at so please be patient and again hope I make sense here and I am not trying to be a wise guy but trying to help as always.
I hope I explained myself OK.
I have many things that I will post on chimneys and will do so shorty.
Robert,
Did not take your reply as wise guy at all. Certainley there is a lot more that goes into chimney construction than the minimum clearance requirements as provided by The International Building Code. The 3,2,10 rule is simply an easy formula to remeber as part of a generalist inspection.
For example here in Florida because of the pressure differintal created during tropical storm events exhaust vents have to be considered as air intake vents creating a whole other set of clearance requirements. Look forward to your future posts on chimney construction as I’ll bet you Canadian guys have a lot more to bring to the table than us South Florida guys
Thank you Mr.Tyson for those kind words and I do hope I can contribute to InterNACHI’S posts.If I do get things wrong some times please excuse me for I am dyslexic and it comes out back wards some times.Please if I do post errors help me correct them and others for I think that by doing this for all to see it will only straighten or understanding of the home inspection business and our brotherhood.
Again thanks.
The National building code calls for a chimney (all chimneys) to be two feet above any structure within ten feet of the chimney. This is to prevent down drafting when the wind blows up, over and down the other side of the structure where the chimney is located. Chimneys are vents for fuel burning appliances that exit through roofs.
Vents through walls are vents and are not chimneys and are used when the intake and exit are closed off from the interior of the building. In other words the combustion air comes in from the outside via sealed pipes goes through the burner and exits the building directly to the exterior via sealed pipes. All high energy furnaces can be set up this way.
???
Prefab gas fireplace-propane.
Flue pipe runs horizontal and concealed 6+ feet and then upward through the roof.
The flue pipe extends through the tile roof, but terminates parallel to the center of 2 single hung second floor windows in a bedroom, and is only 40" from the window.
The flue pipe is also still under the second floor soffit an overhang and ALSO below the second floor valley water run off.
Doesn’t propane have to comply?