Trench depths and cover of pipes Trench routes must be laid out as per the proposal drawings agreed with SGN Connections. The minimum depth of cover for mains and service pipe within private properties or gardens is 375mm. A clearance of at least 250mm should be maintained between gas pipe/fittings and other utilities plant. Please refer to the diagram of the typical utilities plant layout under a 2m wide footpath to prevent third party damage. Digging trenches The bottom of the trench must be prepared as a level bed, suitably compacted to provide firm support under the pipe. It must be free of sharp objects such as bricks, concrete and rocks. Wherever possible the trench bed must have a continuous downward gradient from the building towards the main. Please make sure trenches are safe before any work is carried out in them. Should any digging/reinstatement work be required on third party/shared land, we will need to carry this out. If you decide to dig your own trenches then in most cases it’s your responsibility to dig all trenches on your own private land before we, or our approved contractors arrive on site. You may also need to import backfill material to complete the work. We’d be happy to carry out this work for you at an additional charge. Recommended positioning of utility apparatus in a 2 metre footway * Diagram is not to scale Surface box Pr operty boundary 450 450 295 295 295 295 270 270 260 260 2000mm 430 430 Telecommunications depth 350mm Water depth 750mm – 900mm Gas depth 600mm Cable TV / communications depth 250mm – 350mm Electricity depth HV 450mm – 1200mm / LV 450mm CarriagewayŸ Gas ducting must be yellow, vented appropriately and perforated. Gas marker tape must be laid a minimum of 75mm above the duct to prevent interference damage. Polyethylene (PE) gas, water or cable pipe must not be used as a duct. Ÿ Ducting must be laid in a straight line and should be laid by the most direct route from the main to the termination position – this route is normally perpendicular to the main. The ducting must be laid on a prepared bed or soft ground and the first 75mm backfilled with suitable or imported fine fill. Ÿ The correct size service pipe ducting must be installed at the correct depth, leaving sufficient room at both ends to allow access for connection to the main and the service termination point. The mains connection must be left open with sufficient duct exposed to receive the service pipe, and you must allow a minimum of 1m at the entry point to allow us to assemble the required fittings. The site owner should insert a guide rope in the duct to enable ease of insertion. Ÿ Care should be taken when installing the duct to ensure it is not kinked, blocked or obstructed. If we have to leave site due to blockages or incorrectly installed ducts, you may be charged for any additional visits required. Ÿ If we are unable to insert our pipe into your duct and our ducting requirements are not met, you will be responsible for digging any trenches to lay the new pipe work or incur additional costs for us to carry out this work. Ÿ We do not provide ducting. Ducting Do open windows and doors to help ventilate the gas Do call the National Gas Emergency Number on 0800 111 999. Lines are open 24 hours a day, 365 days a year. Do turn off the gas supply at the meter and make sure any gas appliances are turned off Don’t enter a cellar if you smell gas, even if your gas meter is located in the cellar X X Don’t smoke or use any naked flames X Don’t touch any electrical switches. Turning a switch on or off could ignite a gas leak Gas safety Follow these six steps if you smell gas: Our preferred method of pipe laying is within an open trench OFF For more information, contact us: 0800 912 1700 Pipe size Minimum duct size <=32mm 60mm 63mm 150mmNext >