Flue terminal positioning

Key: — N/A Not allowed, CF Conventional Flue, RS(H) Room Sealed Horizontal flue, RS(V) Room Sealed Vertical flue.

Notes:

1. Terminals should be positioned so as to avoid products of combustion accumulating in stagnant pockets around the building or entering into buildings.

2. Vertical structure in N, O and P includes tank or lift rooms, parapets, dormers etc.

3. Terminating positions should be at least 1.8m from an oil storage tank unless a wall with at least 30 min fire resistance and extending 300mm higher and wider than the tank is provided between the tank and the terminating position.

4. Where a flue is terminated less than 600mm away from a projection above it and the projection consists of plastics or has a combustible or painted surface, then a heat shield of at least 750mm wide should be fitted.

5. If the lowest part of the terminal is less than 2m above the ground, balcony, flat roof or other place to which any person has access, the terminal should be protected by a guard.

6. Notwithstanding the dimensions given above, a terminal should not be sited closer than 300mm to combustible material. In the case of a thatched roof, double this separation distance should be provided. It is also advisable to treat the thatch with a fire retardant material and close wire in the vicinity of the flue.

7. It is essential that a flue or chimney does not pass through the roof within the shaded area delineated by dimensions Q and R.

8. Where protection is provided for plastic components, such as guttering, it is essential that this is to the standard specified by the manufacturer of the plastic components.

• Flue terminals must be positioned to avoid combustion products entering into buildings.

• The flue must be fitted and terminated in accordance with the recommendations of BS 5410.

• The flue must not cause an obstruction.

• Discharge from the flue outlet must not be a nuisance.

• Flue gases have a tendency to plume and in certain weather conditions a white plume of condensation will be discharged from the flue outlet which could be regarded as a nuisance, for example, near security lighting.

• There should be no restriction preventing the clearance of combustion products from the terminal.

• The air inlet/outlet duct and the terminal of the boiler must not be closer than 25mm to any combustible material. Detailed recommendations on protection of combustible materials are given in BS 5410:1

• A protective terminal guard must be fitted if the terminal is 2m or less above a surface where people have access. The guard must be spaced equally (minimum 50mm) around the flue and fixed to the wall with plated screws.

Stainless steel terminal guard

Part No: 7 716 190 050

The following additional guidelines (from part L Exceptions Guidance Document) are recommended when determining the flue outlet position:

• Avoid discharging flue gases into car ports or narrow passageways.

• *Minimum distance of the flue terminal from above ground is 2,100mm where directed to a public footpath, private access route or a frequently used area and 2,500mm from a car parking area.

• **Minimum distance of the flue terminal to a facing wall, fence, building or property boundary is 2,500mm.