Depths of utility pipes and cables (2023)

Unless you live in an off-grid property, in most cases your home should have its own water, gas, electricity and telecommunications services such as phone line and broadband and possibly cable television.

In some situations, utilities such as telephone lines and electricity may be supplied by overhead wires, but in many cases they are supplied by a network of underground pipes and cables.

To ensure that any pipes or cables in the ground are protected from damage, they must be laid at a specified depth depending on the type of utility.

What are utilities?

Utilities are essentially necessary services that include water, electricity, gas, telephone and broadband supplied by a utility to a property to enable residents to have electricity to cook, light, heat and operate appliances, and water to drink, wash clothing and bathing, etc.

Also included under the “Utilities” umbrella are sewage and sewage services.

Unless you generate your own electricity free of charge by solar panels, wind turbines or similar, or have your own well or borehole for water, you will be charged for any gas, water, mains electricity or telecommunications services supplied from the grid.

Likewise, unless you treat and dispose of your wastewater and gray water yourself, you also pay a utility company to dispose of your household waste.

There are a number of different utility companies in the UK, some offering just one service while others offering multiple services.

With most utilities, you pay for the amount you use, e.g. the amount of gas, electricity or water you use over a period of time, but in some cases the charges are simply a fixed monthly fee, e.g. Telephone and broadband or sewage.

When it comes to fees, in most cases you pay for the volume of service you use, plus management and other fees added by your particular utility. In some cases, these fees also include the rental and maintenance of the utility network.

Can I run my own utility pipes and cables?

Whether gas, electricity or water,Under no circumstances can you lay your own supply linesas there are very strict rules on the type of piping to be used, ducting, formation of the trench, connection of a specific supply to the mains, etc. set by HSE (Health and Safety Executive) and OFGEM.

In almost all cases, all work must be performed by a qualified technician to ensure that any given new service pipe or cable is properly installed and connected.

Also, most main gas supply pipes, main water supply pipes, and main power cables are laid under or near public land, e.g. Roads, footpaths, shoulders, etc. and there's no way you can dig a public road without the proper paperwork and qualifications to say you can.

With the above in mind, if you are looking to install a new gas, water or electricity service, it is best to contact your designated supplier and arrange the work through them.

Have no illusions though, it will be expensive but they will have all the necessary contractors, licenses and specialists on hand to get the job done quickly, safely and in compliance with all relevant regulations.

As mentioned above, digging yourself on or near public land is out of the question, but when it comes to digging on your own private land, it may be possible in some cases.

For example, if you have installed a new gas line to your property, you may be able to dig the trench for the new utility line where it crosses your own private land. This can save you a lot of money in some cases.

However, this can only be done in accordance with HSE guidelines and, if applicable, the specifications of your energy supplier.

Also note that your utility company will likely plan the route of the new utility line across your property for you as well.

It is important to note that in some cases the utility company will insist that all work be carried out by their own engineers, in which case this will likely include digging on your own private property.

If your supplier is okay with you doing your own excavation work as said, the specifications will be defined by them and the HSE, but in most cases they will be similar to the specifications below.

How deep should electrical cables be buried in the ground?

When laying electrical cables underground, they should be laid at a depth of at least600mmand it should be run in a way that avoids potential damage from interference now and in the future. Depths will vary slightly depending on cable load and floor type you are laying in:

When burying electrical wire, you should always use armored wire or SWA (Steel Wire Armored Cable) cable, which is protected by an outer steel coating. In the event that a spade or other object hits the cable, the steel sheathing prevents it from being severed.

The steel coating should also be protected with a plastic or rubber coating to avoid any risk of corrosion.

Regarding the potential dangers of protective armor, all problems are solved by grounding it directly to the board, so if there were any problems, the board would immediately trip.

It is possible to use unarmoured cable as well, but if you do so it should be placed in a protective conduit or duct that offers the same level of protection as the armor in an armored cable.

The cable itself should be laid in a trench with a smooth and flat bottom, without sharp objects such as rocks, stones, etc.

The belt and braces approach to burying cables is to also encase the cable in 75mm of sand, e.g. 75mm down, up and to the sides and then put electrical tape or a marker 150mm above it so anyone digging in the ground can find the warning tape and be warned of the wire's presence.

To fully comply with all safety aspects, any new underground wiring, for example to run a new supply to a garage annex, would need to route the underground wire back to a 30mA RCD. So if there is a small problem, the RCD would then trip and cut off the power to prevent serious injury.

How deep should gas lines be buried in the ground?

Where a gas main is laid underground, the HSE specifies that it should be at least 750mm deep in a shoulder or road, but 600mm deep for a footpath. In the case of a gas supply line, it should be at least 375mm deep on private property and at least 450mm deep if routed under footpaths and roads.

To explain the difference between pipes a little more, the gas main is the main supply pipe that runs through your street and supplies various properties, while a gas supply pipe runs from the gas main to your property and connects to your gas meter.

Supply lines then lead from the gas meter into your house to supply your various gas appliances.

All gas supply linesmustconnected to a measuring device. The meter not only records the amount of gas you use so you can be billed for it, but also regulates the pressure of the gas entering your property.

Gas pressure in the mains varies significantly depending on supply and usage, and all household appliances require a regulated supply to function properly and efficiently. Erratic gas pressure can cause equipment malfunction and possible serious injury.

Both your home's gas main and dedicated utility line are managed and maintained by the National Grid or a licensed gas transportation company. If you want to know who your local gas carrier is,You can download a fact sheet from the eth Ofgem website here.

As with the power supplyUnder no circumstances should you carry out gas connection work yourself! This also applies to the installation of new pipelines.

The same applies to all internal gas work,This should only be done by a Gas Safe engineer.

Again, it may be possible to do all the trenching and preparation work yourself if new piping is to be laid across your own private property, but you will need to discuss and agree this with the gas carrier who will be doing the installation.

As for the actual pipe, this has traditionally been cast or ductile iron, but as these corrode over time, polyethylene is more commonly used today.

Gas supply and main lines are also usually colored yellow to easily distinguish them from other supply lines.

The trench in which the pipe is laid must also meet certain specifications.

First, the trench should have a smooth base, free from sharp or jagged objects. If any are found, you may need to excavate another 75mm and fill in with sand or a similarly fine substance.

Gas supply lines should also be laid with a slight incline, away from the point of supply and also in a straight line.

Once the trench is prepared, a layer of sand is used to line the base for the pipe to be laid on top. After installation, a minimum of 100mm of sand is laid over and around the pipe to encase it and the trench is then backfilled with soil.

Warning tape is then laid at least 75mm above the pipe along the full length of the route to warn of the presence of the pipes.

In addition, if other pipes are planned to be laid near the gas supply pipe, a minimum distance of 250 mm should be maintained between them and the gas pipe.

How deep should water pipes be buried in the ground?

Blue MDPE pipe is used to bring mains water to homes and properties across the UK. When laying MDPE water supply pipes, it should be laid a minimum of 750mm and a maximum of 1350mm below the finished floor.

If the water supply line is to be routed close to other supply lines such as gas or electricity, it should be at least 350mm away.

When it comes to digging the trench yourself, it should not only be dug to the correct depth, but cut to a minimum width of 250mm plus the outside diameter of the pipe itself.

After the trench itself has been cut, there are also guidelines to follow regarding bed preparation before laying any pipe.

As with other supplies, the bed of the trench should be level, flat, and smooth, and free of rocks, stones, or similar hard, jagged objects. If this is the case, you may be able to route your whistle directly onto the base.

If this is not the case, the trench must be dug at least 100mm further and a bed of sharp sand laid for the pipe to rest on.

Once the pipe is placed in the trench, it is backfilled, first with a 100mm layer of sand to detect the presence of the pipe and then with a clean bottom.

The soil is then compacted every 300mm to ensure the pipe is held firmly in place.

As is required for other service pipes, a marking tape is placed along the length of the pipe run at least 300mm above the pipe.

A final point to mention is that if a water supply line is to run under a structure, it must be routed through a sealed channel.

How deep should telecommunications cables be buried in the ground?

There are different types of telecommunication cables; Copper cable, fiber optic cable and cable TV cable. Copper and fiber optic cables should be buried 600mm under a road, 350mm under any hard surface and 450mm under a softer surface, while cable TV cables should be buried at least 250mm under hard surfaces such as footpaths.

As with other umbilicals and conduit, all copper, fiber optic, and cable television wiring should be routed in as straight a line as possible with a minimum of bends.

Another important point is that when telecom cables are inserted into a property, they should be laid at a depth of 450mm.

As with other utilities, all wiring and work should be done by or through your telecom provider, e.g. If you want to install a new phone line you will need to contact your phone company who will either install the line for you or outsource it to another company, usually Openreach in the UK.

All cables must be installed in channels. The duct itself must also be equipped with a pull rope so that new cables can be pulled in without any problems. Once the wiring is in place, the line is capped and sealed to prevent damage.

Sealing the canal is of the utmost importance. Because the duct essentially carries a specific utility cable into a property, if hazardous gases enter the duct if it is not sealed, they could potentially leak into the property's interior.

How deep should sewage and surface water drainage pipes be buried in the ground?

In general, there are no specific depth ratings for sewers and drains, in many respects the required gradient of 1:40 to 1:80 for foul water discharge and 1:100 for surface water discharge and the channel you connect to determines the depth at of the pipes are laid.

However,the Building Regulations document Part Hstates that plastic drainpipes should be at least 600mm under gardens and fields and 900mm under roads and driveways.

Where clay pipes are used they should be at least 600mm below ground level when laid in gardens or fields and at least 1200mm below roads and driveways.

If the required minimum depth cannot be reached, the pipes themselves may need to be concreted to ensure they are adequately supported. This is especially important when piping runs under a roadway or driveway.

In terms of trench width, this is usually given as around 300mm plus the width of the pipe used.

As with other utilities, all drains should be in a straight line, avoiding any obstructions or potential hazards. If a bend greater than 22.5° is required, you must provide access through a manhole.

Under normal circumstances, UPVC piping should be laid in the trench on a bed of uniformly sized aggregate with particles no larger than 10mm. If you use clay whistles, however, you must contact the manufacturers for their recommendations.

Almost all drainage work is notifiable work, e.g. Your local building control authority must be informed of the work. If you have questions about pipe or trench specifications, you should ask them and they should be able to advise you.

When it comes to drainage, it's important to use the correct terminology for the specific type of drainage:

• Surface drainage and sewerage: This type of drainage is responsible for removing rainwater from a surface. Above-ground surface drainage mainly refers to roof drainage, e.g. Guttering and downspouts, where underground surface water drainage refers to the subsoil or sewerage that discharges the water
• Foul drainage and sewerage: This type of drain drains dirty water from sinks, sinks, bathtubs, toilets, etc. The above-ground inner part of the drain is called the sanitary sewer, while the underground drain that removes the waste is called the dirt drain or sewer

There is a distinct difference between a drain and a sewer. Generally, a drain refers to drainage for a single property, and a sewer generally serves multiple or more properties.

There is also a distinction to be made with regard to ownership – if there is talk of a private drain or sewer, ownership falls to the property owner, while a public drain or sewer is the property of the "sewer undertaker".

If you want to know more about thedifferent types of drainage you can see our project for dirt and surface water drainage hereand for information abouthow to lay an underground drainage see our project here.

Safety considerations when digging around underground utilities

Before beginning any digging or excavation work, certain plans and guidelines must be prepared and followed.

Damage to an underground utility pipe or cable can be a nightmare at best, and potentially fatal at worst, especially in the case of power or gas lines.

A particular underground utility or cable is essentially owned by the provider that owns or manages a particular utility network, and a requirement related to their ownership is to keep records of where all pipes and cables run.

If you are starting a project that involves excavating the ground, you should first contact any relevant service providers and then ask for the pipe/cable plans for the area you are digging. This should highlight the route that the particular service is running in the area you are working in.

Another good indicator, especially with drainage, is to follow the route of the manhole covers. Drain lines should run in a straight line from manhole to manhole and if you lift the manhole cover yourself you should then see any changes in direction and the direction the pipe is going from that point.

If you suspect that certain utility pipes or cables may be passing through the area where you are working but cannot locate them, you must use a cable or pipe locator or service to pinpoint their exact location.

It is possible to hire cable/pipe locators and do the work yourself or hire a third party to do the work for you.

If you plan to do this yourself, be aware that not all locators actually detect all of the different individual services that may be present in the ground. Make sure the computer or service you are using has accounts for all types of services.

Once all lines have been located in the ground, their entire route should be marked with markers or paint of a specific color for the line to be marked. The colors used should correspond to those specified in theNational Color Coding System for Underground Services.

Once all existing lines have been marked and identified, safe digging can usually begin.

Digging in and around utility lines is risky and potentially dangerous if not done correctly. For full information and guidelines,see the Health and Safety Executive Document HSG47 here. It contains all the details on everything you need to know.

Note: A very important point is that regardless of where a particular plan or marker indicates that a particular service is buried at a particular depth, this is not always the case!

In the past we have found gas and electric cables buried just a few inches in the ground. Just because an official document states that a given gas line should be buried at least 600mm deep at the site you are working on, don't assume this is true!

What to do when subway services are damaged

Let's face it, even if you take every precaution and follow all the guidelines to the letter, accidents do happen, and as we mentioned above, pipes and wires aren't always where they should be.

If an underground utility or cable is damaged:

1. Leave all casualties where they are unless in immediate danger
2. Call the relevant emergency services, fire brigade, ambulance, police, etc
3. Make sure all bystanders are far away to avoid injury
4. Call the owner or operator of the service and inform them of the damage
5. Block off the area with cordons, barrier tape or other warning devices
6. Warn any nearby properties or homes of the damage
7. Do not attempt to repair damaged pipes or cables

If you are dealing with a damaged gas line, this is what you need to doCall the national gas emergency number: 0800 111 999. Make sure no one is smoking and there are no open flames

Warn all nearby properties not to use their gas supply. In some cases this can cause pressure problems within properties or airborne gas can leak into a particular property.

If a main electrical cable has been damaged, do not attempt to remove severed cables from machines. If a digger/excavator has cut the cable, make sure the driver/operator does not leave the machine until the cable has been isolated and is no longer live.

Even if the supply in question does not appear damaged, you should always report a service strike to the owner/operator.

Although water may seem fairly harmless, under high pressure, such as in a water pipe (pressure = 1 bar or 15 psi) can be lethal, so treat it as such.

Working in and around utility and utility lines and cables can be a minefield of problems, but as long as you take the necessary precautions and follow all relevant guidelines, all work can be carried out safely and efficiently.

All project content written and produced byMike Edwards, founder of DIY Doctor and industry expert for building technology.