Waterproofing is one of the key considerations when planning a basement construction or basement conversion.
The ground surrounding a basement is normally saturated and as such, waterproofing measures must be implemented to prevent damp seeping into the walls or floors. There are two waterproofing methods which can be utilised; these are with the application of a cavity drain membrane system or with the use of cementitious tanking
Cavity Drain Membrane
Cavity drain membranes allow for water to penetrate the building, however, before this water has a chance to cause any damage it is captured and held within an air gap. The water is then subsequently redirected to a drainage point, meaning the basement remains completely waterproof.
This waterproofing system boasts several advantages; one of which is that it ensures that the basement construction is never placed under pressure from the water around it. This is because the water simply doesn’t get a chance to apply any force to the walls. Secondly, the air gap itself serves an additional purpose as the circulating air allows the basement to breathe and dry out.
Cementitious tanking is a method of waterproofing which requires a concrete slurry material to be applied to the walls that need to be protected from moisture. The properties of this material allow it to act as an effective defence against water, making cementitious tanking an excellent waterproofing system.
However, this method of waterproofing cannot be used on all basement walls as certain structures, particularly older buildings may be prone to movement under the pressure of the water that has nowhere to go once it reaches the concrete dam. Water pressure can also be responsible for damage to individual bricks therefore a thorough assessment needs to be carried out before choosing this waterproofing method.