Your twin wall flue should have a label with it which will show the distance to combustibles on it.
Flue through roof space.
That s because the combustion byproducts are in a gaseous form so the gases can float up through the flue pipe and out of your roof.
The vertical flue at the ceiling level is surrounded by and attached to a horizontal piece of open 1 2 x 1 2 metal mesh screen about 10 square.
If your furnace has an afue rating below 90 percent it will most likely have a flue pipe that goes up through your roof.
The minimum clearance may be reduced by 50 percent to 225 mm 9 in if suitable shielding is installed either on the pipe or on the combustible surface.
If the roof isn t easily accessible or the engineer isn t worthy of an extras role in the bfg this means that scaffolding may be needed and that roof tiles will need to be moved or replaced.
Minimum clearance from combustible material.
Stainless steel an excellent heat conductor is a common choice for flues and flue liners.
Clay and concrete are alternative options.
If your boiler flue has to face out onto a public space the installer will have to ensure that it s fitted at least 2 1 metres above ground level over head height.
A single wall metal flue vent is not safe if it passes through combustible floors walls ceilings roofs.
Vertical flues can pose issues due to the need to direct the duct through the roof space.
When twin wall flue passes through a cupboard storage space or roof space a guard should be placed that is not closer than the distance to combustibles for that type of flue.
The penetration will be oval to have a round pipe exit vertically through a pitched roof you need an oval hole in the roof.
Vertical flues the majority of boiler flues exit out of a wall horizontally but if the flue from your boiler comes out at roof level then there are also some regulations that need to be considered.
Bends or offsets in the flue can retard the steady outflow of gases.
The metal furnace flue extends vertically through the closet ceiling through the attic and roof.
The gas vent chimney for the furnace should extend at least 3 feet above the highest point where it passes through a roof and at least 2 feet higher than any portion of the house within a horizontal distance of 10 feet.
Often this is 50mm or 60mm but it does vary.
The proper term for this connector is a flue vent connector but plenty of normal people use the word flue or the phrase stack pipe loosely for any sort of chimney or chimney connector.
Position the vent pipe up to the bottom of the roof.
A flue pipe must never pass through a combustible floor or ceiling or through an attic roof space closet or concealed space.
