Basement Waterproofing in London

Basement flooding is a worry you don’t want to have, but when you do, you want it fixing quickly. In London, flooding is a risk for homeowners and businesses. The increase in heavy rainfall means that London basements and cellars are flooding more often.

Basements will almost always be damp because of the way they are made. Moisture present in the ground penetrates through the walls and floors of cellars and basements. Flooding occurs when water in the ground builds up against the structure, creating hydrostatic pressure. The groundwater level can increase because of heavy rainfall, location of the property near watercourses, construction of nearby basements, or a burst water main. You might only see a small amount of water enter your basement during flooding, but you may find that water can enter your cellar quickly in a short space of time.

Whether you have just moved into a London home or your long-term residence is experiencing more flooding problems, it can be treated. With the right waterproofing system in place, you can make basement flooding a thing of the past.

 

 

Waterproofing Your Basement

 

 

Basement waterproofing can be done in different ways, depending on your needs. The appropriate waterproofing system will be installed based on whether you want to use your basement for dry storage or you want to convert it into another room.

If you want to waterproof your basement, you should get a CSSW qualified surveyor to complete it for you. Waterproofing of below ground structures, including basements and cellars, is covered by the code of practice BS8102:2022. The design of your waterproofing system will consider:

  • The proposed use of the basement
  • Accessibility for maintenance
  • Suitability of the chosen method for the structure

 

 

Which Basement Waterproofing Method Is Right For You?

 

 

The code of practice states that the risk of flooding should be assumed at some point during the life of the structure, so you can feel rest assured that your basement is protected if you take the necessary steps. BS8102:2022 provides two methods for waterproofing an existing cellar or basement.

 

Type A Barrier System (Tanking)

The Type A barrier system, better known as tanking, is when a waterproof render or tanking slurry is applied to the walls and floors of a basement or cellar area. This acts as a barrier between your home and the water, keeping water out of your property.

It sounds like the perfect solution, but it might not be right for your home. Tanking relies on obtaining a good bond to the substrate. With many existing basements and cellars constructed of brick, the preparation required can often mean the use of grit blasting or bush hammering, which can create a lot of dust and debris. If a good bond is not obtained, then the risk of failure is increased especially when the tanking render is subjected to hydrostatic pressure. There is also a risk of movement causing cracking of render coats and failure.

If you want to add fixtures and fittings to your London basement or cellar, this can cause more problems with the tanking method. Penetrating the render can lead to dampness or even flooding, which would invalidate your warranty and put your property at risk. If you aren’t sure whether basement tanking is right for you, contact us for a survey.

 

 

 

Type C Cavity Drainage Membrane

 

 

The most popular method for waterproofing basements and cellars is the Type C cavity drainage system. This is the industry standard and the most reliable system you can get for your home. A polymer studded membrane is installed and applied to the walls and floor. 

 

 

Using drainage channels around the perimeter, it leads to either a sump and pump or existing drainage systems. By managing the water entering the basement, you won’t have to worry about additional stresses induced within the structure from hydrostatic pressure.

Anyone hoping to modify their basement or cellar space after waterproofing will find that the Type C system makes it easier to add fixtures. A dry lined wall can be installed onto the cavity drainage membrane, allowing the addition of electrical outlets, shelving, and other fixtures easily and without compromising the seal.

Unlike the Type A method, there is little to no preparation needed, meaning that the new cavity drain system can be installed with minimal disruption to your home. You can start using your new space in no time.