Drain Lining

There are many causes of drain damage. Tree roots can cause damage, as well as water infiltration and natural ground movements. Once a drain pipe becomes damaged, leakage can start to cause major problems. If soil surrounding the pipe becomes saturated, the whole drainage system can be compromised. What’s more, drain replacement is often very costly and time consuming.

Fortunately, there is an alternative. Drain lining, or drain relining, offers an effective way of repairing damaged drains without having to remove them. For this reason, it is often referred to as trenchless or no-dig technology. Traditional dig and replace excavations can usually be avoided thanks to this technique.

What is drain lining / drain relining?

Drain lining is essentially the installation of a protective layer inside the drain pipe. This serves to provide the drain pipe with additional protection. A pipe can also be relined as an effective method of repairing a damaged pipe.

This procedure can be carried out whilst the drain is still in place. This typically means that no excavation of earth or other material is required to carry out the repair.

When is it used?

In many instances a cracked drain pipe can be repaired with minimal disruption. Effective drain relining prevents the need to completely replace a pipe. It can be carried out on a wide range of size pipes, from 100mm up to 1500mm.

This method of repair can save a lot of money, especially in the case of underground sewer pipes. The excavation of earth as well as the removal of trees, footpaths, or driveways can cause significant disruption and incur significant costs.

Relining is not solely for use on underground pipes. We are also able to reline vertical pipes and chutes. We regularly carry out these kinds of repairs to save homeowners and landlords from large costs. It is possible to use this method to repair old cast iron pipes, which can often be surrounded in stone or brickwork. In these cases, relining is a cost-effective alternative to removing the drain completely.

Image of old drain pipe. Drain lining can save old damaged pipes

The technique also be used to navigate bends and even repair a damaged bend. This makes drain lining extremely versatile. The more times we can use this method, the more often we can save our clients time and money.

How does it work?

A polymer lining is bonded to the inside walls of the drain pipe. Although this does reduce the volume inside the pipe, the smooth surface of the lining aids the flow of water. This means that the effectiveness of the drain pipe is usually improved by the addition of a new lining. Furthermore, the lining is generally more corrosion-resistance than the wall of the pipe itself.

It is essentially the creation of another pipe within the existing pipe. Not only does the lining prevent leaking, it also provides structural strength to the pipe.

What is the procedure for drain relining?

During the process, a number of steps are carried out:

Drain jetting

Initially, it is important to discover the extent and exact location of any damage within the drain pipe. Typically, the inside of the drain pipe is cleaned using a process known as drain jetting.

Image of drain jetting used prior to drain lining
Click here to take a look at our article on drain jetting.

It is important the drain is clean for a number of reasons. Firstly, the inside of the drain pipe must be clean so that an effective inspection can be carried out. Secondly, the inside of the pipe must be free from debris to enable the lining to effectively adhere to the pipe.

CCTV drain survey

Once the pipe is clean, a CCTV drain survey is then carried out. This involves inserting a high resolution waterproof camera down the drain in order to visually inspect the inside of the drain.

Image of CCTV drain camera used prior to drain relining
Click here for more information on CCTV drain surveys.

Once the survey has been carried out and the pipe has been inspected, a diagnosis can be made. The engineer can then recommend the best cause of action. Work can then commence on the relining, should this be deemed to be appropriate.

Before being entered into the drain, the lining is cut to length and marked for the access points, if required. Different types of liner and materials are used depending on the specific case.

Cured-in place pipe (CIPP) lining

Cured-in place pipe is one of the most common and effective methods of relining a drain pipe. The lining comes in various sizes and is pre-shaped to fit into the drain pipe. They can be made out of various materials but the most common is a polymer. The CIPP lining is saturated with resin prior to being inserted or pulled into a damaged pipe. Usually, the lining enters the pipe via a manhole or access point. It is then forced into the pipe using water or air pressure, or it is pulled into place.

Once in place, an airbag is inserted along the length of the pipe before being inflated. This inflation ensures that there is pressure on the lining as it sets. The resin on the lining is then left to cure. Typically, this process takes around 60 minutes. As it cures it fills in cracks and forms a tight-fitting, jointless, and corrosion resistant layer inside the pipe. The curing process can be accelerated by the use of hot water or steam.

The damaged pipe is now completely lined all the way along the length of the pipe. A new drain pipe has effectively been created without ever having to remove the existing one.

Patch Lining

It is not always necessary to line the entire drain pipe. In many cases there is a localised area of failure which can be treated without having to line the full length of pipe. Also, it is not always practical to shut off a drain while repairs are being carried out. This is especially true for large, deep sewers. A technique known as patch lining can be used. As well as causing minimal disruption, it typically saves time and money. Also, patch lining is not only useful for large drains. Thanks to advances in technology, patch lining can now be used on small diameter home drains.

Unlike the traditional CIPP lining which comes pre-shaped to the pipe, the patch lining comes in the shape of a square patch. This patch is then saturated in resin before being wrapped around a pipe packer. The pipe packer is essentially like an airbag that can be inflated and deflated. The packer is inserted into the pipe, up to the point of the defect. The packer is then inflated in order to maintain pressure on the lining as it sets. It is left in place for around 60 minutes until the resin has cured. The packer can then be deflated and removed. This process can be repeated several times throughout the pipe if required.

The process is fairly quick and straight-forward. It causes much less disruption and cost than excavating and is also more cost-effective than traditional CIPP lining.

How long does the lining last?

Drain lining is not just a short term solution. It is an effective method of significantly prolonging the life of a drain pipe.

Image of short/long term. Drain lining is a long term solution to damaged drains

It is difficult to say how long each lining will last as every situation is different. However, all our linings are tested to meet the 50-year design life demanded by the Water Research Centre (WRc).

We can proudly say that the vast majority of our drain relining will last for decades to come.

How much does it cost?

Providing an accurate estimate is difficult as the cost varies so much. The cost will depend on many factors, including the extent and location of damage. However, we can assure you that drain lining / drain relining it is an extremely cost-effective way of repairing drains. Where possible, we always like to use this method, it can save the client money and reduce disruption.

Please get in touch today if you would just like some more information on the cost.

Why choose Drain Jets?

We are specialists with a wealth of experience in the drainage industry. Along with our highly trained crew, we have state of the art drainage equipment. We can come and fix your drainage problems in a cost-effective and timely manner. We carry out drain lining / relining for a wide variety of clients, including industrial and domestic.

If you have problems with your drains or would just like some more information please get in touch today.

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