What Is Moling and When Is It Used for Water Pipe Installation?

If you need new water pipework installed or an existing supply pipe replaced, you may have heard the term "moling" mentioned as an installation method. But what exactly is moling, and when is it the right approach?

How Moling Works

Moling — also known as impact moling or trenchless pipe installation — uses a pneumatic percussion tool (the "mole") that is driven through the ground beneath the surface. The mole creates a tunnel through the soil, through which a new pipe can be pulled or pushed into place.

The key advantage is that only small launch and reception pits are needed at either end of the run. The ground between these two points remains undisturbed, which means driveways, lawns, paths and patios are protected from excavation.

When Is Moling Used?

Moling is commonly used for:

• Installing new incoming water supply pipes
• Replacing old or damaged supply pipework
• Routing pipes beneath driveways, block paving or patios
• Crossing gardens or landscaped areas without surface damage
• Avoiding existing underground services

Moling vs Traditional Excavation

Traditional open-cut excavation involves digging a trench along the full length of the pipe route. This works, but it can cause significant disruption — particularly on properties with finished driveways, established gardens or complex landscaping.

Moling avoids this by working beneath the surface. The result is faster installation, less reinstatement work, and lower overall costs in most cases.

Is Moling Suitable for Every Job?

Moling is highly effective in most soil types but is not always suitable in heavily compacted ground, areas with extensive underground services, or very short runs where open-cut would be equally practical. A site survey will determine whether moling is the right approach for your property.

Moling for New Supply Installation

If you need a new supply installation, moling is often the preferred method for routing the new pipe from the boundary to the property — particularly where the route crosses a driveway, path or garden.