What is a cavity membrane

What is a Cavity Membrane?

If your home has had problems with damp in the cellar or basement, then you will already likely know how annoying it is to have a space in your home that you’re unable to use. Even worse, having damp in the home can also cause health issues for people living in the property. The good news is that damp does not have to put you off from utilising that unused space and adding extra rooms and value to the home. A cavity drain membrane system is the most ideal way to ensure damp proofing for a damp cellar, keeping your new room dry and safe for decades. Before converting your cellar into a liveable space, keep reading to find out more about this damp proofing system and why it might be an ideal choice for your property.

Cavity Membrane and Damp Proofing

Cavity membrane drainage systems are suited for using in cellars, basements, or vaults. The main purpose of such a system is for damp proofing, and a membrane made from high-density Polyethylene is typically used, which is installed on the floors, walls, and sometimes the ceilings of the basement. In many cases, it can also include a specific drainage channel that is installed to divert water towards a sump chamber. It will also usually include a pump that pumps that water outside and away from the building.

What is a Cavity Membrane and How Does it Work?

Cavity membrane drainage allows water in at the back of the membrane. From here, it is then diverted to where it should go. This is different to tanking or structural water proofing, which completely blocks any moisture from reaching the walls. The cavity membrane system can either be directly plastered onto or dry lined. This should be decided prior to starting the installation. In a situation where no natural drainage is available, a sump chamber and pump will be installed to direct the water away from the building towards a suitable area, such as an outdoor drain. There are two types of Type C waterproofing membranes: wall membranes and floor membranes. There are different types of each one to choose from based on your needs. Floor membranes usually have larger stud profiles.

Cavity Membrane and Damp Proofing in London

In the UK, many people live in properties with some degree of damp. Damp issues can make it impossible to use your basement as storage, as it will only cause damage to your belongings. And before you can convert your basement into a liveable room, damp will need to be dealt with to ensure that the walls stay dry for years to come. Otherwise, damp can damage your cellar conversion by causing issues with the internal décor such as crumbling plaster, flaking paint, curling wallpaper, and rotting skirting boards. It can also change the entire atmosphere of the space from somewhere that is cosy and inviting to somewhere that’s unsightly, uninviting, and seems dirty. If the damp issue isn’t dealt with before converting the basement, it can lead to serious problems down the line.

Why Do You Need a Basement Waterproofing Membrane?

There are several problems related to having damp internal walls or a damp basement. If you convert your cellar without having damp proofing carried out, the damp will make the whole area feel less comfortable. It can cause damage to the furnishings and decorations, and lead to an unpleasant and musty damp smell. Along with this, damp will also make your basement less energy efficient, which can lead to you paying more on your monthly expenses overall. There are also health risks linked to having damp in the home, especially for people who are young, elderly, or have respiratory conditions such as asthma.

How Do You Install a Cavity Wall Membrane?

Cavity drainage membranes are a popular method for waterproofing a basement. They work through internally lining a basement to divert any water into a drainage system when it enters the basement structure. The British Standard for waterproofing classifies Cavity Drainage Membranes as Type C waterproofing. The first element of setting up a cavity drainage system is to provide drainage that is accessible and maintainable. This can be done through Delta Perimeter Drainage Channels or with a modular drainage system. Cavity drainage systems shouldn’t be connected to a combined sewer, as this will create a higher risk of sewer surcharge and nasty smells.

What is a Drainage Membrane? Preparing the Area

Before a cavity drainage membrane can be installed in the cellar, any new concrete should be pre-treated using an anti-lime treatment that will prevent limescale from forming in the new drainage system.

What is Type C Waterproofing?

Type C waterproofing is designed to provide a structure with drained protection, or cavity membrane drainage systems. They are a popular option for damp proofing existing cellars and basements and a popular option for installing in new homes with a basement. The reason why drained protection is needed is that earth-retaining walls are subjected to hydrostatic pressure, which occurs when external water pressure is exerted on the structure. While some primary resistance will be provided by external basement walls, any structural weaknesses may cause water to get into the property and lead to floods and other destruction. Type C drained protection ensures that any cellars, basements, and other structures located below-ground are protected if water ingress occurs. It involves using a specially-designed cavity membrane to cover floors and walls, along with the installation of a drainage system designed to channel and redirect water entering the property. As a result of this, any items in the basement will not be affected if water gets in.

When To Use a Cavity Wall Waterproofing System

In most instances, a cavity wall waterproofing system will be used for refurbishment projects in existing properties like a renovation or conversion of the basement. They are also often used in the construction of new build properties. In some instances, you may also need to think about using combined damp protection. This will usually be recommended if there are risks that are considered to be high, or if the potential damage caused by the cavity membrane system failing is a lot. If this is the case for your property, then you can also use type A protection, which involves external or internal tanking, or structurally integral, which is known as type B protection, alongside your type C drained protection.

What are the Benefits of Cavity Membrane Drainage Systems?

There are various benefits of using a cavity membrane drainage system for damp proofing in your property. These are:

No External Changes Needed

Unlike some other types of waterproofing systems such as tanking, type C cavity membrane waterproofing systems do not require any external changes to be made to the structure of your property. This allows you to get a high level of water ingress and damp protection without the need for a lot of building work and labour. It’s also typically a cheaper option compared to other damp proofing types.

Reliable Protection

This waterproofing system type is designed to provide protection for your property that is reliable and long-term. It protects your belongings and home from damp problems and water ingress for many years.

Protect Your Property From Structural Damage

A cavity drain membrane system provide an option to safely deal with any water that may have entered a building. With this controlled drainage system, the water can be easily removed, and pressure is prevented from building up against the structure of the internal walls. Since there is an air gap left between the wall and the membrane, this allows the structure and materials to breathe, which encourages drying out after being subjected to water ingress.

Can Be Used on Any Property

You can use a cavity membrane waterproofing system on both new builds and for refurbishing older properties. This type of waterproofing can be used for more peace of mind with new properties that are built on land that is susceptible to flooding. For older houses, a cavity membrane waterproofing system provides a reliable and robust waterproofing option for homeowners who want to refurbish a cellar or basement into a space that is usable and liveable.

Who Should Install a Cavity Waterproofing System?

In general, the installation and fitting of a cavity drain waterproofing system is not a task to consider doing on your own. For an installation that is compliant and reliable, you should hire a trained professional with a good knowledge of the complete installation process and the specifications that need to be met. This is because even small mistakes during installing the membrane can lead to weak patches, which can render the entire system inefficient by causing pressure to build up at these weak spots. This increases the risk of flooding and damage to the property.

If you are converting a basement or cellar or building a new cellar or basement in a new property, then damp proofing is one of the most important parts of the process to consider.