If an underground drainage system is not correctly installed, or if particularly heavy equipment has been operating above the installed pipework (such as a compactor) then unfortunately you may find that a drain pipe can collapse. It can also sometimes be caused by a large amount of movement in the surrounding ground, tree roots or by freezing temperatures.

This costly and disruptive problem is often cited as the most serious drainage issue that can occur as it is often only fixable by replacing the pipework, so in this article we outline how you can spot a collapsed drain and what action you need to take to deal with it.

Key Takeaways:

A collapsed drain can be caused by a variety of factors including incorrect installation, ground subsidence, freezing water or tree roots.
An inspection should be carried out to confirm if the drain is collapsed, usually via a drainage CCTV survey.
Often the only way to repair a collapsed drain will be a replacement of the collapsed pipe.
The responsibility of the repair may not be yours, so double check first before arranging it.

Identifying a Collapsed Drain

A collapsed drain can be difficult to notice initially, however below we’ve detailed several key signs and symptoms that you should look out for before a problem becomes too severe:

Signs of Damp

When a drain collapses, it causes the water flow to be majorly disrupted, leading to extra strain on water and sewage pipes which can start to leak as a result. If this occurs, or a collapsed section of drain is directly underneath a property – including garages and outbuildings – you may notice patches of mould or damp on walls or floors which should be investigated and dealt with as soon as possible.

Insufficient Drainage

If you have noticed a reduction in drainage performance in a kitchen sink, bathtub, shower, or bathroom sink then that could be an indication that there is a problem. The root cause will usually be a one-off blockage but drain damage can also be the cause. As a first step, it is usually recommended that you use domestic tools and treatments where there is a slow drainage problem, such as a waste pipe cleaning rod, or drain unblocking fluid. However if that fails to resolve the issue, the drains should be checked by a professional drainage company using a CCTV survey to thoroughly investigate and locate the cause.

Strong Sewage Smell

Unfortunately, a very common sign of a drainage issue is a strong sewage smell in or around a home or building. In the case of a blocked drain, this odour will soon disappear once the blockage has been removed, however if the root cause is an unidentified collapsed drain, the unpleasant smells will linger until it has been properly fixed.

Sinking Ground

In addition to a distinct sewer smell, subsidence or sunken ground around a drain is a visual indication of a drains collapse, as water leaking from the pipe into the surrounding soil can cause a slump if the damage is left awaiting repair for a prolonged period of time.

Rodent Infestations

Unfortunately a collapsed sewer drain can also make it a lot easier for rats and other unwelcome pests and rodents to gain access to a property. Where this occurs, any infestation should be dealt with before tackling the issue with the drain pipes.

Non return valves or rodent flap valves can be installed at the end of pipes to stop rodents from getting in if you have an exposed end of a pipe.

Cracks and Damage

Where a collapsed drain has been an unidentified issue for a while, it can eventually lead to cracking within a home or building as a result of water slowly but steadily leaking into the foundations. In severe cases, this may mean that a property needs to be evacuated until necessary repair work is carried out – to both the drainage system and the house or building itself – as the water damage can impact the property’s structural integrity which can be extremely hazardous.

Sewage Blockages

If a home or building regularly experiences drainage problems such as frequent pipe blockages or sewage backups (both of which can be extremely unpleasant to deal with) this suggests that there is either significant damage to a drain pipe or there is a collapsed drain. Where needed, a team of drainage experts will be able to carry out a thorough inspection and confirm if there has been a sewer collapse via an investigative CCTV survey.

Repair Responsibility

As a collapsed drain is one of the most serious issues that can occur with drainage systems, once you have identified it as a problem, it needs to be rectified as soon as possible – this usually involves an excavation by drainage experts to ensure that the full extent of the damage is properly repaired. Who is responsible for the required repair work can depend on the positioning of the drainpipe in question, and this needs to be confirmed before you appoint a drainage repair provider. However generally, if the damage is inside the boundary line of your property then it’s up to you to ensure it’s fixed and if it falls outside of that boundary, then the onus is on the local water supplier.

If the issue is on your property, unfortunately it can be expensive to have it professionally repaired, however it is worth checking your home or building insurance policy as the costs may be covered depending on what your provider classifies as accidental damage.

Avoiding Future Issues

While there are a number of causes of collapsed drains that you might not be able to control, such as tree roots, ground movement, freezing temperatures, or simply old drain systems, the most common culprit is neglect or failure to carry out regular maintenance over the long term. To help prevent sewer collapses or other longer-term drainage issues, it’s best to be mindful of what you put down your drains and you should ensure that they are regularly cleaned to prevent an accumulation of grease and debris. Some drain repair services also offer periodic maintenance and cleaning services to prevent the gradual buildup of substances such as silt, grease or debris that can reduce the capacity of drainage pipes.

Affordable Replacement Pipes

If you need further guidance on collapsed drains, or you are looking for high quality replacement pipes at extremely competitive prices, please let us know and our expert team will be happy to offer advice on our extensive product range of drainage pipes and fittings.