Preparing for external waterproofing on new build

What Is External Waterproofing?

3 August 2021

Waterproofing your property is a serious and necessary step when it comes to property management, especially if you want to avoid the expensive pitfalls of moisture ingress, flooding and all of the troubles associated with an ill protected structure.

So, to that end, what kind of waterproofing systems are available for application onto your property, and which are suitable for you? In this article, we hope to answer any and all questions you might have about external waterproofing, otherwise known as ‘Type A Waterproofing’ – or more commonly, tanking.

What Is External Waterproofing?

Before anything else, let’s run through exactly what you can expect when it comes to external waterproofing on a below-ground structure. So, first off, you may be confused as to what external waterproofing is called when it comes to below ground structures.

You might have heard it referred to as Type A waterproofing, barrier protection, or tanking, but it all means the same thing – external waterproofing applied to a below-ground structure.

As to the waterproofing itself, the process is actually very easy to understand. Usually, a form of waterproof coating in the form of a liquid slurry is applied to the cellar or basement walls, commonly when the building is first being constructed when we are talking about external application.

This process essentially creates a waterproof seal around your basement, which is what earns it the name ‘barrier protection’. That waterproof coating does not allow for any water to flow through, and as a result, the basement itself will remain dry and habitable as long as the waterproof coating remains intact.

All of this is constructed in line with BS 8201 Waterproofing Regulations (which is where the designation Type A comes from), so you can be sure that on application your property is in line with official British Waterproofing Standards.

When Should Type A External Waterproofing Be Used?

Barrier protection waterproofing being applied to the exterior of a property might not be the end-all solution when it comes to waterproofing a basement. This is because barrier protection is a form of waterproofing best employed when the main threat to a below-ground structure is the presence of damp.

That’s because barrier protection is a form of external waterproofing that is best used when the property is away from free-flowing water and other forms of immediate flood risks. This is due to the fact that a barrier protection form of external waterproofing is going to completely protect your property from water altogether.

This will mean that any free-flowing water pushing against the sides of your property below-ground structure will only build up and add pressure to the side of the basement – which could lead to the walls giving in, and crumbling.

This is not the only problem that can crop up with barrier protection waterproofing when applied externally. You could find that once applied, the barrier itself diverts water to a different area below ground, which could lead to higher loads of water pressures building up. This then puts stress on your properties walls and possibly bowing them and therefore compromising the waterproofing entirely.

You also have to consider that application of external barrier waterproofing requires the complete excavation of the area around the walls of the below-ground structure to be applied, so in most cases, barrier protection waterproofing is applied on the construction of the building itself.

It also means that the application must be executed perfectly, otherwise there will be further problems with water ingress – yet there is no real way to check if the application has been successful until the excavation has been backfilled and the waterproofing solution is underway.

What Is the Point in External Waterproofing?

Sadly, some property owners fail to see the point in having external waterproofing applied to their below ground structures. Perhaps they believe that because these properties are below ground, and therefore sheltered from heavy rainfall that they don’t need to be protected.

This however is unfortunately not the case. Properties with below ground structures are significantly at risk from flooding and other structural issues that can all stem from improper or non-existent waterproofing.

Think of how rainfall and other moisture can soak into the earth. This is the predominant method through which moisture and other liquids can find their way into a basement – not via out and out flooding of a property from rivers bursting their banks or similar.

Rain soaks into the earth, which then travels downwards through the ground. This, naturally, makes the earth wet, and if that earth is in turn pressed against your property then the risk is run of moisture being transferred from that earth into the outside of your basements wall. What could that mean?

Firstly, it could mean that you have a damp basement. More specifically, it could mean penetrating damp, which is a form of damp that only gets worse with time if left untreated. This damp can naturally expand and lessen the structural integrity of the whole structure. Not only will this mean you have the damp in the wall as a problem to solve, but eventually a leak could sprout, which outside of flooding your basement could further the faults in your basement’s walls.

That isn’t mentioning the other detrimental factors that can occur from a lack of waterproofing. Damp leads to ruined building materials yes, but it can also provide the perfect home for black mould to grow and fester, which can have a real negative effect on your health.

Do I Need External Waterproofing?

If you have noticed that your property is suffering from water ingress and damp in its below-ground structure, then it’s probably time you had an expert opinion.

Our surveyors are ready to evaluate your property and give you a professional opinion on what kind of waterproofing will suit your property, be it a barrier protection layer applied externally, or a cavity drainage system applied quickly to the interior of your property, our team can recommend and install a waterproofing solution that suits your property quickly and efficiently.

Find out what kind of waterproofing is right for you by calling 0800 288 8660 or by contacting us online.