Civil engineering explained.

Under DIN VDE 0100-520, an underground cable up to 1 kV, for example NYY-J, is laid at least 0.6 m deep, and at least 0.8 m deep under driveways and carriageways. It is bedded in sand, about 10 cm below and above, with a warning tape above the sand layer. The cable may only be connected by a registered electrical contractor.

There is no uniform statutory depth that applies throughout Germany. What counts are the generally accepted codes of practice, i.e. DIN, VDE and DVGW rules, and the requirements of the network operator concerned. On public roads, the conditions of the local authority's excavation permit also apply.

That is set by the provider. Telekom, for example, requires a trench on the property at least 30 cm deep and 15 cm wide for a microduct bundle of two 7 mm tubes or a DN 75 empty duct. Some other providers specify greater depths.

Deep enough to be frost-free. For house connections, water suppliers usually require between 0.9 m and 1.5 m of cover; GELSENWASSER, for example, requires at least 90 cm. The trench is correspondingly deeper: about 1.0 m for 90 cm of cover.

Gas house connections usually have about 0.8 m of cover, as stated, for example, in the connection conditions of EWE NETZ. The pipe itself is laid by the network operator. Gas and water connections must not be built over or planted with trees.

With the highway authority's consent, fibre ducts may be laid shallower and narrower than conventional utility lines. DIN 18220 sets the rules: when milling in paved surfaces, the slot is 5 to 15 cm wide and 30 to 60 cm deep; when saw-cutting, it is 1.5 to 11 cm wide.

Under the network operators' connection conditions, gas and water service pipes must not be built over or planted with trees, and the route must remain accessible. The route above power and fibre lines should also be kept clear so that they can be reached in the event of a fault.

A protective duct or line is laid from the network in the footpath across the property to the wall of the house, using an impact mole or in an open trench. The line enters the house through a core-drilled opening, and the building entry seals it against water and gas. Inside, the network operator installs the termination point, for example the house connection box for electricity or the building entry point for fibre. Finally, the pits or trench are backfilled and the surface is reinstated.

A hammer driven by compressed air that forces its way through the ground. It pushes the soil aside and compacts it instead of excavating it. The protective duct is pulled into the resulting bore either straight away or afterwards. An impact mole cannot be steered and only travels in a straight line.

With an impact mole, if the run is short and straight and the soil can be displaced. Two small pits are then enough, and the front garden, paving and driveway stay untouched. Stones, construction rubble, old foundations or groundwater rule it out, in which case an open trench is dug. Whether it is feasible is clarified during the site visit.

Depending on the equipment and soil, up to about 25 m, according to the manufacturer TRACTO-TECHNIK. For fibre house connections, WEMAG, for example, assumes about 10 m per run. For longer distances, additional pits are dug.

Often yes, if the network operator allows it. At EWE NETZ, for example, customers may dig the trench, backfill it and reinstate the surface; at MVV Netze they may also do the core drilling. The network operator lays the line itself; at MVV Netze the trench is inspected and approved beforehand. Electrical connections may only be made by a contractor listed in a network operator's register of installers (§ 13 NAV).

Usually in the basement or the house connection room, ideally on the street side. The requirements for house connection rooms, walls and recesses are set out in DIN 18012. New builds often get a multi-utility building entry that brings several lines, for example electricity, gas and water, into the house together through one sealed opening.

The construction work itself is usually quick; depending on the soil, an impact mole can manage up to 15 m per hour. The preparation often takes longer: for electricity, gas and water, Netze Duisburg, for example, quotes several weeks for preparing the quotation and a few more weeks until an appointment is scheduled. In fibre rollouts, connections go live once the local network is complete.

Under DIN 4124, trenches up to 1.25 m deep may, under certain conditions, be dug with vertical sides and no support. Deeper trenches generally need sloped sides or shoring. Soil type, loads at the edge of the trench and water are also decisive.

That depends on the depth, the line and the working space. For a fibre house connection, Telekom accepts 15 cm; for a water house connection, GELSENWASSER requires at least 60 cm. If people enter the trench, DIN 4124 specifies minimum widths for the working space.

Yes, even on your own property. Network operators provide plans of their lines, often online, many of them, for example, via the BIL portal. Anyone who digs without utility records and damages a line risks being held liable for the damage.

Stop immediately and secure the area. If you smell gas: no ignition sources and no mobile phones in the danger zone; clear the area and call the fire brigade (112) and the network operator's emergency service. Keep your distance from power cables. Report even minor damage to the sheath, as it often leads to failures later.

Usually three: the excavation permit or consent from the local authority or highway authority, a traffic order from the road traffic authority for barriers and signage, and up-to-date utility records from all network operators. Depending on the location, further permits may be needed, for example a permit under water law.

For a normal utility trench on your own property, usually not. Even so: obtain utility records, follow the network operator's requirements and check with the local authority beforehand if trees, property boundaries or larger excavations are involved.

With the open-cut method, a trench is excavated and then closed again. With the trenchless method, the surface remains almost untouched: the line is pulled in underground by horizontal directional drilling (HDD) or an impact mole, and only launch and reception pits are needed.

Mainly on length and depth, the soil, the surface (asphalt, paving or unpaved), shoring and dewatering, traffic management, and how the excavated material is recycled or disposed of. With a bill of quantities and drawings, we can provide an accurate quote.

Civil engineering in the sense of Tiefbau covers everything built below ground level: utility construction for electricity, gas, water and telecommunications, earthworks, sewer construction and the substructure of roads and paths. Several of these areas often overlap on a single construction site.

StoneCraft is a civil engineering contractor from Dinslaken. We handle civil works and utility construction, earthworks, house connections, road construction and paving, fibre rollout and horizontal directional drilling (HDD) for backbone routes, using both open-cut and trenchless methods. We also reinstate surfaces and handle disposal with documentation.

Our focus is the Ruhr area, the Lower Rhine and NRW. From our head office in Dinslaken, we can reach Duisburg, Oberhausen, Wesel, Voerde, Bottrop and Essen quickly. We have also completed projects in Lower Saxony, Hesse, Saxony-Anhalt and Saxony, in places including Münster, Gelsenkirchen, Neuss, Leverkusen, Wuppertal, Bocholt, Paderborn, Garbsen, Frankfurt am Main, Halberstadt, Chemnitz and Dresden. All locations are shown on the project map.

Mainly for construction companies. As a subcontractor to the contractors appointed in each case, we have worked on rollout projects for the networks of SachsenEnergie, Telekom, 1&1, Deutsche Glasfaser, Vodafone, Westconnect and UGG (Unsere Grüne Glasfaser). We also take on contracts directly, for example from network operators, municipal utilities, local authorities and businesses.

Yes. We reinstate asphalt, paving and footpaths to specification. Excavated material and construction rubble are separated and recycled or disposed of with documentation.

Send us your bill of quantities, drawings or key details via the enquiry form or to info@sc-stonecraft.de, or call us on 02064 7322442. We will get back to you promptly with any questions and a quote.