Common Causes of Drain Blockages

What causes hair to block bathroom drains?

Hair is a leading cause of blocked bathroom drains. Loose strands wash into plugholes and collect in the trap below. When mixed with soap scum, conditioner and other debris, the hair binds into dense tangles that restrict water flow.

How to prevent it

• Fit a mesh hair trap or plug strainer over bathroom drains

• Clean visible hair away after each shower

• Flush with hot water and baking soda once a month to reduce build up

Why do kitchen sinks often become blocked?

Kitchen drains frequently clog due to grease and food particles that stick to the inner pipe walls. As grease cools, it solidifies and narrows the passage. Starchy leftovers like pasta or potato peel swell with moisture and worsen the blockage. Even coffee grounds and eggshells can collect in bends and joins of the pipework.

Preventative tips

• Scrape food waste into the bin before rinsing

• Pour cooled oil into a container instead of the sink

• Fit a sink strainer to catch particles and dispose of it regularly

Can flushing the wrong things cause blockages?

Toilets are designed to handle only water, human waste and toilet tissue. Flushing wipes, nappies, cotton buds or other hygiene products causes clogs because they do not break down in water. These materials get stuck in bends and join other debris, quickly forming solid blockages.

What to do instead

• Only flush human waste and toilet paper

• Provide bins in every bathroom to dispose of everything else properly

How do tree roots get into pipes?

Underground drainage pipes can develop small cracks from age or movement. Tree roots are naturally drawn to the moisture escaping from these points. Once inside the pipe, the roots spread and trap debris. This can lead to blocked or even broken pipes, especially in older clay or pitch fibre drainage systems.

Detection and removal

• Arrange a CCTV drain inspection to confirm root intrusion

• Use mechanical root cutting and pipe relining to restore flow

What happens when pipes collapse or break?

Older or poorly installed pipe systems are at risk of damage from ground pressure, vibration, corrosion or root growth. Pipe collapse leads to restricted flow and soil ingress which can back up wastewater. In hard water areas, scale from calcium and magnesium deposits also reduces pipe diameter.

What helps

• Use CCTV drain surveys to assess internal pipe condition

• Replace or reline damaged sections using no dig techniques

Can weather cause drain problems?

Blocked surface drains are common after heavy rainfall, especially in gardens and driveways. Leaves, silt and debris wash into gullies and grates and block flow. During storms, these obstructions cause standing water and increase flood risk.

Simple steps to help

• Clean leaves and debris away from grates after windy or wet weather

• Install drain guards or leaf covers where trees overhang drainage areas