How to Approach Basement Waterproofing

How to Approach Basement Waterproofing

If your property is undergoing a renovation, or if you are simply trying to convert your basement, at some point waterproofing will need to be considered. Basement waterproofing refers to a number of techniques that aim to stop water from entering a property, and ideally a basement should have access to both drainage and sealers for maximum effect. A competent builder will know how to install these features and be able to offer suitable waterproofing advice along the way, but as there are a number of options to choose a background overview could come in handy.

Membranes and barrier protection products are arguably the cheapest and most effective way to waterproof a basement. These can be applied both internally and externally, and can be installed before or after the basements construction stage.

A chart showing what can happen if you don’t have waterproofing in your basement.

Points of potential water ingress

Types of Waterproofing

  • Pre applied membranes - these are usually attached to the floor and the vertical walls. After they are secured they are combined with a fleece fabric layer for extra protection, which is then bonded using concrete.
  • Post-applied membranes - these are applied after construction work has been carried out. Typically, they are applied to the structure and welded with hot air to create a strong bond.
  • Liquid applied membranes - these come in a range of materials and are sprayed onto surfaces that require waterproofing. These are particularly useful to waterproof areas that are hard to reach.
  • Geo-synthetic / clay liners - these liners or membranes have a natural clay mineral inside of them called Bentonite. Bentonite expands when it comes into contact with water meaning that it can form a barrier to prevent any further damage to a property. However, it must be noted that these Bentonite based membranes are only suitable for newer properties.
  • Mastic asphalt – this material is applied to the walls in a series of coats (much like paint). This does provide a good level of waterproofing, but it is rarely used nowadays due to safety concerns.
  • Crystalline powders / slurries - these come in ready-made blends that include cement, sand and other active materials. These are applied directly onto a concrete surface to form a protective barrier.
  • Multi-coat waterproofing render – this render is generally applied after the majority of work has been carried out because of ease of use. Multi-coat waterproofing renders are applied using a trowel, brush or spray and work in a similar way to crystalline powders.
This is what can happen when water gets into your basement.

This is what can happen when water gets into your basement.

The products highlighted above are generally referred to as barrier protection products, and they are often seen as one way to improve the waterproofing basement. However, to maximize effectiveness it may be worthwhile combining one of these products with a quality drainage system or an integral waterproofing product.

If you need a basement waterproofing system installed in your home, then use a construction company for quality workmanship. A properly installed basement waterproofing system can prevent structural problems like cracks, spalling and acid damage, while it can give you peace of mind knowing that your property will be safely stored.

Basement Tanking Systems

Waterproofing a basement is essential if you live in the UK. If waterproofed correctly, your basement will be free of structural problems, mould, and most importantly health risks. This means that you will not have to pay for any costly repair charges as well. There are a number of ways that quality waterproofing can be achieved, but one method that is recommended by any qualified person offering waterproofing advice is a basement tanking system.

A builder waterproofing a basement.

A builder waterproofing a basement.

A basement tanking system is the term given to a liquid or slurry based coating applied to the structure of the basement. This lining or coating effectively forms a tank around the basement and protects it from any damage that may be caused by water. If you are thinking about converting your basement, or if you use it for storage, then a tanking system will have to be considered. The majority of basements will have mouldy and damp walls that offer little waterproofing protection, and generally, these walls will enclose a space that can be deemed uninhabitable. By having a quality basement tanking system installed this problem can be solved.

If you decide to make an enquiry with a construction company, the chances are you will be confronted with two choices. These choices are a; multi-coat render tanking system or a slurry based tanking system. Of course, there are additional choices that are available, but these are the two most common options. Let’s take a look at them in more detail:

Multi-Coat Render Tanking Systems

As this does not use any solvents or flammable materials that are present in other renders, they are ideal for enclosed spaces like basements. They contain waterproof mortars and a slurry coating that provides a decent level of protection. This can be applied to additional external concrete surfaces for a similar waterproofing effect. multi coat render system

Slurry Tanking Systems

These have similarities to the multi-coat render tanking systems, but the layer that is created and applied is thinner. Due to this, a slurry based tanking system may not be suitable for a project that has high levels of hydrostatic pressure. If you are going to use this system, then ideally your walls should be in good condition. In any case, you will need to ask a professional for waterproofing advice beforehand.

Application slurry coat

Application slurry coat

Both options can be referred to as cementitious systems. This means that they are cement based coatings applied to walls and other surfaces in order to prevent penetrating damp. Cementitious tanking systems are ideal for small and ‘awkward’ areas. Another advantage of using waterproof tanking is that a drainage pump and system will not be needed, unlike other waterproofing solutions. If you feel that you could benefit from the many advantages offered, get in contact with a construction company who can offer you plenty of waterproofing advice. Furthermore, they will also be able to assist with installing a basement waterproof tanking system in your property.

Basement Waterproofing

Whatever the role is that your basement plays in your homes setup it is vital to have it correctly waterproofed. A properly waterproofed basement will prevent structural damage, damp, mould, spalling and even flooding from happening. There are a number of ways that a water-tight basement can be achieved, and for maximum effect, it is best to combine these techniques. Multi-coat rendering, slurry tanking and quality drainage systems are all good options to ensure a basement is properly waterproofed, but there are even more options to be considered as well. Here, we will explore more about basement waterproofing.

The BS8102 document from the code of practice for protection of structures against water from the ground refers to three main ways that a basement can be waterproofed. These are; barrier protection (type A), structurally integral protection (type B) and drained protection (type C). All of these techniques will be employed by professional builders as following this code is generally seen as a good standard of practice.

Barrier Protection (Type A)

Barrier protection systems come in a number of varieties, including; resin based coatings, cement slurries and renders. These are applied to the walls and the surfaces of a basement, and this effectively creates a seal. This seal cannot be penetrated by any damp, and these barrier protections systems are particularly useful for areas that may be hard to reach by other means of waterproofing. Additional advantages of type “A” protection is that it is often the cheapest option and the easiest one to carry out. However, it may not be suitable for properties that have a large amount of hydrostatic pressure.

Structurally Integral Protection (Type B)

Unfortunately, this technique is limited to new build properties only as its features are built into the structural framework. However, it is something that should be considered if you are building a new home. New property’s that incorporate this method use reinforced concrete, hydrophilic gaskets and sealants to promote an increased resistance to water vapour.

Drained Protection (Type C)

Type C protection allows water to pass through a cavity in both interior and exterior walls before it is pumped away into a drainage unit using a sump pump. There are a few options to choose from in regard to drainage protection, and some of these options include cavity drains, sump pumps and perimeter drains. Type C is an excellent waterproofing choice as it offers tried and tested results, whilst also relatively trouble free. However, in any case, a professional will need to install this system, and semi-regular professional maintenance checks will need to be carried out. These are the three waterproofing protection methods that are recommended by the BS8102 document, but as suggested earlier these techniques should be combined for the best results. Construction companies always follow these guidelines, and if you need any more waterproofing advice get in contact with a professional for some invaluable guidance.
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