Page 66 - B8773-AEW-XX-XX-PP-A-0001_[P8]_Contractors Manual

4.1.2 Gas Services - Best Practice Guidance
Ventilation Below ground entry connections
Where the gas meter is to be located internally In stores where the gas connection is entering
and within a purpose built cupboard, adequate the building below ground level a sand filled
ventilation must be provided. entry pit must be provided.
• The ventilation must be 2% of the nominal
floor area Best practice
• The ventilation must be both high and low • Excavate a pit which allows the service pipe
level to enter the building
• The housing in which the meter is located • Gas service pipe must be minimum 450mm
must be completely sealed so gas can only below ground level
escape from the housing / cupboard to the • Gas service pipe must enter the building to
external atmosphere a minimum length of 450mm before it can
• All air vents are to be pest and rodent proof bend to rise above the floor level and must
have a further 450mm from the gas service
In the event of a gas leak, the gas must not be pipe to the inner side of the pit
able to escape into the room the cupboard • The pit must then be filled with sand
is located, behind boarded walls or to upper
floors or other parts of the building.

Best Practice
• Install air bricks at high and low level within
the cupboard (so gas can escape to the
external atmosphere)
• Ensure the cupboard is fully boarded and
sealed. (Gas can become trapped and
permeate in the void between the wall and
the boarding)
• Ensure the top of the housing has a ‘ceiling
/ roof’ and no upper floors can be seen (as
gas will seep through and travel to upper
parts of the building)

4.1.2 Gas Services - Best Practice Guidance 3 September 2018