Flat Roof Wood Burner External Flue Regulations

Some require larger diameter flues.

Flat roof wood burner external flue regulations.

This means if the pitch of the roof is below 38 degrees. The top of the flue opening should be 3 ft 0 92 m above any roof surface. Flue height regulations flues need to be 600mm higher than the highest part of the roof within 3 metres. A chimney flue should never be less than 5 diameter and only certain stoves can use them defra approved stoves that allow a 5 flue can be attached to this diameter flue.

You can leave solid pack chimneys exposed and braced. The flue or chimney must terminate at a minimum1800mm above the combustible surface as shown in diagram 3 below. 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. As you d expect the requirements controlling new chimneys flues and appliances are safety based and very detailed.

This is for masonry chimneys. For buildings with flammable roofs such as felted thatched or shingle roofs the flue or chimney the regulations are different. It means any pipe penetrating a roof must be three feet above the roof line on the up slope side of the penetration. Many require a 6 flue.

Where to measure the flue termination flue outlet height from the flue termination is measured from the very end of the chimney flue pipe where the flue gasses discharge. For a gas vent or type l vent this height must be 2 ft 0 61m or more. Gas flue blocks have been specifically designed for use with gas effect fires. To make sure that there is no hazard the flue outlet needs to be sufficiently far away from the roof adjacent buildings and roof windows.

They must not be used on a wood burning or multi fuel appliance under any circumstance. If there is a steep roof or nearby obstruction the chimney will need more length above the roof to meet code. The concrete blocks have an integral narrow rectangular flue way. Flues that are more than 3 metres away from the highest part of the roof need to be 1000mm above the flue penetration.

If the flue exits the roof further down then it must extend high enough to acheive 2 3m of horizontal clearance. A vertical line drawn along the up roof side of the chimney from the roof surface to the top of the chimney flue opening shall be at least 3 ft in height.