bhartley
February 4, 2009, 12:21am
1
Would you recommend this flue be raised??
lkage
February 4, 2009, 12:40am
2
Here’s a guide:
Table of Type B-Vent Rooftop Clearance Requirements
The 1992 Vent Sizing Tables require that all Type B gas vents terminate above the roof with a listed cap or listed roof assembly in accordance with the manufacturer’s instructions.Vent caps 12" and smaller may terminate a distance above the roof if 8 feet or more away from a vertical surface as follows:
Continues to 21/12 pitch at 8.0 feet
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.
From: http://www.inspect-ny.com/chimneys/B-Vent_Chimneys.htm
belliott
February 4, 2009, 1:26am
4
I am more concerned about the giant shadow of a robot I see in the picture,which is castings itself on to the roof image.
It appears to have a strange dome or bulb like contraption sticking from its head.
Almost pom pom like.
1 Like
bhartley
February 4, 2009, 3:26am
5
That is my stocking cap 25 degrees at 4 PM!!
belliott
February 4, 2009, 3:29am
6
I know. hahahahaahaha
How far from the vents was the flue?
Looks ok.
We had this issue last month. (caused a debate)
bhartley
February 4, 2009, 3:42am
7
Thanks!! Approx. 12 inches.
belliott
February 4, 2009, 4:02am
8
kshepard
February 4, 2009, 4:07am
9
lkage:
Here’s a guide:
Table of Type B-Vent Rooftop Clearance Requirements
The 1992 Vent Sizing Tables require that all Type B gas vents terminate above the roof with a listed cap or listed roof assembly in accordance with the manufacturer’s instructions.Vent caps 12" and smaller may terminate a distance above the roof if 8 feet or more away from a vertical surface as follows:
Continues to 21/12 pitch at 8.0 feet
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.
From: http://www.inspect-ny.com/chimneys/B-Vent_Chimneys.htm
Darn-o! I thought the 2/10 termination rule applied to all combustion vents for adequate draft reasons.
belliott
February 4, 2009, 4:11am
10
Yeah, thats what I used to think.
Just looking at it makes you see down draft potential.
kshepard
February 4, 2009, 4:14am
11
Are those tables in the current IRC?
belliott
February 4, 2009, 4:18am
12
Good question.
belliott
February 4, 2009, 4:23am
13
kshepard
February 4, 2009, 4:28am
14
But if that’s Hart & Cooley’s guide, they’re just one manufacturer. Might their information not apply everywhere?
belliott
February 4, 2009, 4:46am
15
Looks like a very good general information on B vents.
The diagram explains the general height rule very well.
sfetty
May 8, 2016, 5:10pm
16
lkage:
Here’s a guide:
Table of Type B-Vent Rooftop Clearance Requirements
The 1992 Vent Sizing Tables require that all Type B gas vents terminate above the roof with a listed cap or listed roof assembly in accordance with the manufacturer’s instructions.Vent caps 12" and smaller may terminate a distance above the roof if 8 feet or more away from a vertical surface as follows:
Continues to 21/12 pitch at 8.0 feet
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.
From: http://www.inspect-ny.com/chimneys/B-Vent_Chimneys.htm
Thanks Larry! Bing found this useful thread.
jbernard
December 27, 2016, 2:58pm
17
New construction. This stack appears to be too short, but I want to double check before getting into a discussion with the builder. Roof is 7/12 pitch. The stack is 22 inches tall and 21 inches from the roof and does not extend above the roof peak. Thoughts?
ccurrins
December 27, 2016, 7:13pm
18
Flat to 7/12 - 1.0 foot **above the roof surface. ** No problem.
