Flues need to be 600mm higher than the highest part of the roof within 3 metres.
How high chimney above roof line uk.
Chimney height may need to be increased by 2 3 per 1000 feet of elevation although added height generally equates to stronger draft there is a point where the system can become too long and over drafting might occur.
The chimney must extend at least 3 above the highest point where it passes through a roof.
The height of the chimney above the roof surface measured at the up slope side of the chimney from the roof surface to the chimney top should be at least three feet the green line in our photo.
Other factors can influence the necessary height of the chimney such as house stack effect and high altitude.
Degrees the height of flue or chimney stack will need to be at least 1800mm above the roof when not close to the ridge.
This is a bit of an odd measurement and chimney clearance case because the chimney side is actually about 8 away from the roof edge.
And at least 2 higher than any portion of a building within 10.
We also have the 2 3m rule.
Look at the top of your chimney where the smoke comes out.
Anon the chimney outlet needs to not only be proper height above the roof surface but proper distance from any opening that could take flue exhaust.
Two things determine chimney draft.
If the pitch of the roof is 38 degrees or greater the termination point of the flue or chimney will need to be 2300mm horizontally from the roof line and roofing material.
The chimney should extend at least 3 feet above the roof surface it penetrates and 2 feet higher than any roofline or other obstacle within a horizontal distance of 10 feet.
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.
They intend to make sure that the chimney draws properly and that a fire hazard does not occur.
Homes built on varying terrain have their own set of chimney and flue regulations.
The top of a chimney pipe must extend at least 2 feet above the peak of the roof if the pipe is within 10 feet of the peak.
Specifications aren t there to merely cause you problems.
If the top of the chimney is within 600mm 60cm of the ridge it should finish 60cm higher than the ridge.
If the pipe is farther than 10 feet from the roof.
Both above the flat roof and 2 feet above the point at which a horizontal line from the chimney would touch the highest portion of the nearest roof.
Flues that are more than 3 metres away from the highest part of the roof need to be 1000mm above the flue penetration.
The 10 foot rule explains the clearance you need.