Hand excavation in soil classes 1 to 4

Hand excavation is priced per cubic metre. The volume is measured "in the bank", meaning the soil as it lay in the ground before anyone touched it. A trench 10 m long, 0.4 m wide and 0.8 m deep is 3.2 m³ of excavation. Dug soil loosens, though, and takes up more room on the heap. Depending on the soil, this is usually roughly a tenth to a third more. Keep that in mind when you order a skip or plan where the spoil will go.

The excavation item itself covers breaking up the soil, throwing or lifting it out to the edge of the excavation, and roughly levelling the bottom. Estimates usually list these related tasks separately:

• Moving spoil by wheelbarrow to a more distant spot on the plot
• Loading and removing spoil from site
• Shoring, meaning support for the excavation walls
• Pumping water out of the excavation
• Backfilling and compacting in layers
• Stripping topsoil, if it is to be kept separately

When you compare quotes, check that you are comparing like with like. One crew may include moving the spoil round the back of the house. Another may leave it lying beside the trench.

By hand or by machine?

A mini digger shifts in an hour what two people dig in a day. Hand work still has its place. It is more precise, it does not shake the surroundings, and no machine has to drive over your lawn or paving. Near buried services it is often the only sensible option. In practice the two methods are usually combined: the machine takes out the bulk, and the corners, the bottom and the areas around pipes and cables are finished by hand.

Engineers describe soils in detail, by grain size, plasticity and strength, and European practice follows EN standards for this. A price list needs something simpler, so this one uses a scale based on how hard the soil is to dig. The higher the class, the harder the soil is to break up and the less one labourer can dig in a day. Three variants share this page: the main item for soil classes 1 to 2, and two variants for digging to a depth of 1 m in class 3 and class 4 soil.

Classes 1 to 2: light soil

This covers topsoil, sands, loose and slightly cohesive soils, and light loams without larger stones. A shovel does most of the work and a pickaxe is only needed now and then. The work goes quickly, but in dry sand the walls collapse easily. Light soil is easy to dig, so people tend to forget about supporting the sides. Do not make that mistake.

Class 3: medium soil

Typically cohesive loams, clayey soils, sandy gravels with small stones, and the compacted ground often found around older houses. You will not get far without a pickaxe, and the spade only goes in with effort. Output drops noticeably and labourers tire faster. Watch out for wet clay. It sticks to the tools, and ground that digs like class 3 in summer can become very slow work in a rainy spell.

Class 4: heavy soil

Hard, dried-out clays, gravels with cobbles and boulders, very stony ground, and old made ground full of rubble and broken concrete. This is pickaxe and crowbar work, and sometimes an electric breaker helps. Every larger stone has to be levered out and lifted. Output is several times lower than in light soil.

How to find out the class before work starts

The most reliable method is a trial pit. Dig a hole in one or two places down to the planned depth and look at what comes out. A site investigation report helps too, if you had one done for the house design, and so does asking the neighbours. It is very common for the top layer to be easy and for hard clay or stony gravel to start at around half a metre. Before work starts, agree with the crew how the job will be charged if the soil changes on the way down.

Buried services

This is the most important point of the whole job. Before the first spade goes in, you need to know what is underground. Ask the utility companies (gas, electricity, water and sewerage, telecoms) for plans of their networks. Use the national service location scheme if your country has one, or ask for the services to be traced and marked on site. On your own plot, think about your own private lines too: a pipe to a well, a cable to the garage, irrigation, land drains, a septic tank or a soakaway.

Near marked services, dig carefully, by hand and without a breaker. Utility plans are not always accurate, so treat the marked position as approximate. If you hit warning tape or a bed of sand, a pipe or cable is close.

Permission and agreements

An excavation is usually part of a bigger project: a fence, an extension, a service connection or a patio. Whether that project needs planning permission, building regulations approval or nothing at all depends on the country and the specific case. Do not assume it is exempt. Check with your local building authority. If you live in a flat, the building management or owners' association has the final say on digging in shared grounds. Digging in a public space or next to a footpath needs consent from the local council or highway authority.

Setting out and space for the spoil

Mark the outline with a string line and pegs or spray paint. Set the depth from a fixed reference point, such as the door threshold. Agree where the soil will go. Spoil must not be piled right at the edge. Keep it usually at least about half a metre back, so it does not load the wall of the excavation or slide back in. It makes sense to keep topsoil on a separate heap, because it is useful later for landscaping. If the soil is leaving site, order the skip in good time and place it where there is a reasonable barrow route to it.

What should be ready before the crew arrives

• Utility plans obtained and services marked out
• Outline and depth of the excavation marked
• Clear access, with shrubs, paving or kerbs removed
• Agreed place for the spoil or a skip on order
• Access to water and electricity if a breaker or pump will be used

An experienced crew starts by stripping the topsoil and setting it aside. Then they dig in layers instead of going deep in one spot. Trenches are dug in sections. Pits for footings are taken down evenly across their whole area. The walls are trimmed with a spade as the work goes on, so they stay vertical or at the agreed slope.

From a depth of about 0.8 to 1 m the soil can no longer be thrown comfortably over the edge. Deeper excavations are worked from an intermediate step, with the soil passed up in stages, or lifted out in buckets. That is also why the heavier soil variants on this page are limited to 1 m: with depth the work slows sharply and the risk grows.

Depth is checked with a straight edge and spirit level, a dumpy level or a laser, always from the fixed reference point. Footings for a fence, carport or extension are usually taken down below frost depth. That depth depends on the climate. It is shallower in mild coastal regions and deeper inland and in colder countries. The design or local building regulations give the exact figure. For pipe trenches, the crew also has to think about the fall and the sand or gravel bed that goes under the pipe.

Finally the bottom is cleaned out. Loose soil is removed, the bottom is levelled, and nobody should walk on it more than necessary. For foundations it is good practice to trim the last few centimetres just before the concrete goes in, so the bottom does not get wet or frozen.

How long it takes

Time depends mainly on the soil class, the depth and width of the excavation, and how far the soil has to be moved. In light soil a fit labourer can dig several cubic metres a day. In heavy, stony ground it is usually only a fraction of that. A narrow trench is slower per cubic metre than a wide pit, because there is less room to swing a tool. Rain slows things further, because wet soil is heavier and sticks.

A trench collapse is one of the most dangerous accidents on a building site. A cubic metre of soil weighs roughly two tonnes, and even a fairly shallow trench can bury a person who is kneeling or bending down in it. The rule from practice is simple: the deeper the excavation and the looser the soil, the more the walls need support.

• Many national rules require shoring or battering (sloping back the sides) beyond a depth of roughly 1.2 to 1.5 m, and loose or waterlogged soil may need it at shallower depths, so check the health and safety rules where you live
• The safe slope depends on the soil, and sand holds far worse than cohesive clay
• Spoil and materials are never stacked on the edge
• Check the walls before going in after rain or frost
• Nobody should work alone in a deeper trench

Buried services call for strict rules. If you damage a gas pipe or smell gas, leave the area at once. Do not use naked flames or switch any electrical devices on or off. Call the gas emergency number for your area or the emergency number 112. Only a qualified, registered gas engineer may work on the pipe. Never touch a damaged electrical cable. Move away and call the electricity network operator. Any work on electrical lines must be done by a qualified electrician.

Take extra care when digging right next to an existing house. Digging below the level of its foundations, or underneath them, can undermine their stability. That is no longer ordinary excavation. It is work on the structure and belongs in the hands of a structural engineer and a specialist contractor.

You cannot judge how demanding hand excavation is, and therefore what it costs, from the cubic metres alone. The same volume can be an easy half day or a gruelling week.

The job is easier with:

• Light, dry soil without stones
• Open space around the excavation and a short barrow run
• Permission to leave the soil on the plot
• A single depth throughout and no services nearby

The job is harder with:

• Hard clay, gravel with boulders or old made ground full of rubble
• Tree roots that have to be cut through
• Groundwater, or rain that floods the trench
• Tight spots, digging against a wall or under roof overhangs
• Services that force the crew to work centimetre by centimetre
• Greater depth, shoring and lifting soil out in buckets
• Long barrow runs across the garden or up and down steps

Over-digging the bottom. If the excavation goes deeper than needed and loose soil is then thrown back in, a soft layer forms. A footing or pipe laid on it will settle. An over-dug area should be filled with concrete or compacted gravel, not with soil from the heap.

A softened or frozen bottom. If an excavation stands open for weeks, the bottom gets wet, turns to mud and freezes in winter. Soil like that loses its bearing capacity. A foundation excavation should be concreted as soon as possible.

Spoil on the edge. A heap of soil at the edge pushes on the wall. The wall collapses and part of the work has to be redone. It is far worse if someone is in the trench when it happens.

Digging without service plans. A cut cable or a damaged gas connection means danger, a repair at your own expense and a delay to the whole project.

The wrong fall in a trench. For drains or land drainage, a badly graded trench bottom passes straight into the pipe. Water then sits in the pipe and it blocks.

Backfilling in one go. Soil tipped into a trench all at once without compaction settles over time. A dip appears in the lawn, or a sunken rut under the paving. Backfill goes in layers, and each layer is compacted.

If you have a healthy back and some time, you can dig a shallow trench yourself, for example for a land drain, fence post holes, or a duct for a garden cable that an electrician will then connect. Leave deeper excavations, digging in loose soil next to the house, and any digging near gas or electrical lines to professionals.

1. Find the position of all services on the plot and get plans from the utility companies.
2. Check with the local building authority whether the project you are digging for needs permission.
3. Mark the outline with string and pegs and choose a fixed point for measuring depth.
4. Get your tools ready: spade, shovel, pickaxe, crowbar, wheelbarrow, straight edge, spirit level, work gloves and sturdy boots.
5. Strip the topsoil and keep it on a separate heap.
6. Dig in layers and place the spoil at least about half a metre back from the edge.
7. Near marked services, dig carefully with a shovel only, without the pickaxe.
8. Measure the depth as you go and, for a trench, check the fall.
9. Level the bottom, remove loose soil and keep off the bottom from then on.
10. After rain, check that the walls are not loosening before you step in.
11. Use the excavation as soon as possible, by concreting or laying the pipe, then backfill in compacted layers.

Once an excavation is backfilled or concreted, nobody can check it any more. Inspect it before the next stage starts, ideally together with whoever will pour the concrete or lay the pipes.

• The size and position of the excavation match the drawings or the agreement
• The depth has been measured at several points from the agreed reference point
• The bottom is level and free of loose soil, mud and water
• A pipe trench has the correct fall along its bottom
• The walls are stable and supported where the excavation is deeper
• Spoil lies at a safe distance from the edge
• Nearby services are undamaged and any exposed pipes or cables are protected
• Topsoil has been kept separately if that was agreed
• The surroundings are tidy and spoil removal has been handled as agreed
• The excavated volume in cubic metres has been agreed jointly before the invoice is issued