Different Types of Damp Proof Courses and How to Choose the Right One for Your Home

Different Types of Damp Proof Courses and How to Choose the Right One for Your Home

3rd July, 2025

Do you have wet spots on your ground floor walls? Is there a musty smell lingering in the air? Is your paint or wallpaper bubbling or peeling? If so, your property is probably suffering from rising damp, a common problem in London caused by your walls absorbing water up from the wet ground! Fortunately, the damage caused by rising damp can be prevented by the presence of a damp proof course that forms a protective layer between your structure and the ground.

The following are some of the different types of damp proof courses to help you choose the right one for your home!

Chemical Injection – This chemical damp proof course involves injecting a cream or gel into a wall to create a layer that repels water. The installation involves drilling 10mm holes into the wall about 150mm above the external ground level. The waterproof liquid is then injected into the holes. This is a great solution to rising damp that can last for decades to come.

Mortar Injection – This damp proof course is quite similar to chemical injection, but it’s a mortar enhanced with chemicals that’s injected into the drilled holes instead of a liquid. Mortar injections are particularly useful for walls that contain voids or rubble inside their structure, the mortar can fill in the gaps and seal the wall to stop any rising damp from occurring.

Cavity Wall – Waterproof material is installed between the inner and external walls to form a barrier that prevents rising damp from entering.

Electro Osmotic – If you prefer a non-chemical damp proof course, then an electric osmotic solution might be the answer. Titanium and copper wiring are installed into the brick to carry a small electrical charge that reverses the wall capillarity’s polarity, pulling down any rising damp back below the level of the damp proof course. It can be even more effective than an injection in stone walls.

Membrane – A damp proof membrane course is a plastic material installed beneath the structure’s concrete slab to keep it dry. Membrane damp proof courses are able to last for decades and the application is fast and simple.

The type of damp proofing course best for your home may depend on when it was built. Older homes often lack them and need to have one installed! New houses are required to have them in place from the very start. If your new home has a rising damp problem, it’s likely that its damp proofing is subpar or wasn’t installed correctly. In these cases, chemical injection solutions will probably be the best. If you have an older home and are doing a major renovation then a physical solution could be installed.

At London Damp Surveys, our experienced surveyors use cutting-edge equipment to diagnose damp issues so our inspections are always performed to the highest standard. If you have rising damp issues, call London Damp Surveys on 0207 305 5997 and we’ll send a surveyor to assess your home!