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How are Drainage Gullies Used?

Gullies are often a vital part of a good underground drainage system, but their uses are not always clear. In this article, the experts at Total Pipeline Systems will explain the most effective ways in which drainage gullies and gully traps can be installed and used.

What are Drainage Gullies?

You’re likely to need a drainage gully if your property is subject to considerable amounts of flowing surface water. They help to drain away that fluid while preventing unpleasant smells from escaping back to the surface.

There are a variety of types of gully available depending on your requirements. Bottle gullies are roddable, as their central chamber can be easily removed for cleaning.

P Trap gullies, on the other hand, cannot be cleaned in this way due to the shape of their outlet, which can sit at either a 90° or 45° angle.

How are Drainage Gullies used?

Drainage gullies connect to underground drainage systems, helping surface water to drain away into those systems without releasing any smells.

They are ideal for domestic gardens or commercial outdoor spaces.

Gullies work by allowing water to flow through their inlet and out of the other end, whilst always keeping a reservoir of water below the level of the outlet. This water creates a seal between the two openings, preventing any smells from escaping.

The typical grid that tops off a drainage gully should sit flush with the ground and the body of the gully should be installed below - ideally in a dip in the ground so that surface water can be directed to its opening.

What additional accessories might my gully need?

P Trap gullies tend to require the addition of a hopper, and it is highly advisable to install a grid over gullies that are more likely to get clogged with debris.

You can place your grid directly onto a bottle gully, on the other hand.

To ensure that your bottle gully sits at the right height, you may require a raising piece. If you need to fit a square grid to the gully, you can purchase a square top adaptor - which also works with the raising piece.

Square top adaptors provide easier edges to work with if you intend to pave the area around your grid.

Why might I need a Drainage Gully?

Whether surface flooding is a common problem on your property or occurs only occasionally, a drainage gully can help to keep your land dry at all times.

This can prevent water damage to landscaping or wear, tear and discolouration that walls may otherwise suffer. It will also help to prevent unpleasant stagnant pools and patches of slippery algae or moss from forming.

Surface water will be channelled away from your property and into an underground drainage system, ensuring that it does not collect and cause problems.

For more information about our underground drainage products, contact Total Pipes today on 01254 382000 or email