The minimum chimney heights above roof are in the article above.
Minimum chimney height above roof.
For 18 feet of run you would have a rise of 72 inches.
3 at roofline and 2 at 10.
The height of the chimney shall be measured from the firebox floor to the top of the chimney flue.
3 16 1 number.
Chimney height regulations chimneys need to be high enough to ensure that smoke is directed away from where it might be harmful to your neighbours.
On a flat roof may not be tall enough.
If the chimney or flue exits the roof within 600mm horizontally of the ridge then the flue or chimney should be a minimum of 600mm above the ridge.
The chimney is a minimum for 3 above the uphill side of the roof and 2 higher than anything within 10 feet.
Diagram 2 shows the area on a traditionally constructed non flammable material roof where the flue must not terminate.
What is the 2 foot 10 foot 3 foot rule.
The minimum chimney height recommended for minimum performance of wood burning and multi fuel appliances is 4 5 m from the top of the appliance to the top of the chimney.
The flue or chimney outlet must be above and outside of the shaded area.
This clearance is set up to help prevent any embers from landing on the roof.
The chimney in this example must extend 52 above the roof measured from uphill side of the chimney.
At this point we cover everything in the rule.
The current code states that chimney openings need to be at least 300mm higher than the highest part of any roof within 3 6 metres of the chimney.
Round chimney flues shall have a minimum net cross sectional area of not less than 1 12 of the fireplace opening.
For the case you describe there are other distances like from windows and depending on the total chimney height even meeting the above roof minimum distance 3 ft.
The chimney must extend at least 3 above the highest point where it passes through a roof.
When a chimney is not adequately supported by ties or securely restrained in any way its height h when measured from the highest point of intersection with the roof surface gutter and so on should not exceed 4 5w provided the density of the masonry is greater than 1500 kg m 3 that is.
Chimney heights and termination.
The distance between the cowl of the flue and the adjacent roof wall structure should be higher than 2 3 mtr.
Positing a chimney on the home relative to the rest of the home may cause it to draw better.
If the previous calculation results in the required height of 64 inches we can see that the top of the pipe will not rise above the roof peak but would still meet the requirements of the rule.
This means that below 38 degree roof pitches that the height of the flue outlet should be at least 1800mm above the roof when not close to the ridge and above 38 degree roof pitches the flue outlet height should be 2300mm horizontally back to the roof flue height figures are given in the table above where the flue is not close to the ridge.
For the next example you have a shorter chimney height.
