Under the boiler flue position regulations the flue has to be positioned a certain distance from any parts of the home that can be opened up such as windows and doors.
Flue through roof regulations.
This means that the flue outlet needs to be positioned sufficiently high above the roof surface and surrounding buildings to prevent it being affected by wind eddies or downdraughts.
If the flue passes through bedrooms it should be boxed in with an inspection hatch situated in a specific place.
In this case the flue goes upwards and then out through the roof.
Vertical flue joints in attics must be bracketed.
Any vertical flue joints if your flue is going through the roof for example must be bracketed with specific flue brackets every 800mm 1000mm.
Above the roof surface with a listed cap or listed roof assembly.
How high does the flue have to go.
If the flue exits the roof further down then it must extend high enough to acheive 2 3m of horizontal clearance.
A gas vent shall terminate in accordance with one of the following.
A venting system shall be designed and constructed so as to develop a positive flow adequate to remove flue or vent gases to the outdoor atmosphere.
G2427 6 5 503 6 6 gas vent termination.
Also at every joint.
A roof or any big object really creates eddies swirling patters of air and areas of high and low pressure which can reduce draw.
A vertical flue looks similar to a very small chimney and can be seen spouting out steam when the heating is on.
The above points only really apply for flues that exit the home horizontally through a wall but that doesn t mean there aren t any regulations if your boiler flue goes vertically out of the roof.
How far this is will depend on the size of your boiler but is typically between 30 60cm above below or to the side of an opening.
As placement of the vertical flue is more complex and convoluted than a standard horizontal flue it is more costly.
In the loft it will likely need some type of mesh protection.
This flue runs up through your house and exits through your roof.
The twin wall flue must pass through the ceilings and roof.
And there s a very good reason for this.
The building regulations identify the zone for this but any of these dimensions may need to be increased where there is exposure to.
When installing a new twinwall flue system if the flue exits the roof within 600mm horizontally from the ridge high point of the roof then the flue must extend a minimum of 600mm above the ridge.
