Man on his knees looking at a basement sump and pump

Signs of Improper Basement Waterproofing

3 October 2023

If you own a basement then you are probably already aware of the ever present threat of flooding, and the steps that you have to take as the property owner to keep your basement dry.

To some, basement waterproofing is something that must be arranged and installed, especially if the property is older and hasn’t any protection in place already. To others, it’s something that comes with a property when they move in, and these are the people that might not be aware of the different signs that a waterproofing system is failing, or what to look out for when it comes to arranging maintenance or repairs.

So, if you own a property that features basement waterproofing and you want to know what to look out for when it comes to signs of improper basement waterproofing, then this article should help.

Request a survey

Concerned about basement flooding? Call 0800 288 8660 or

The Signs of a Properly Waterproofed Basement

Cavity drain membrane in a basement

If you do own a property with a below ground structure such as a basement or a cellar, then you might well be wondering what the signs are that the waterproofing has been completed properly, and that your basement is correctly protected.

Obviously, the first sign is that your basement remains dry – even in the harshest of rain storms. The only way in which water could possibly enter your basement should be via groundwater. Basically, if the local river has burst its banks and the streets are flooded, at that point even the most comprehensively waterproofed basement might spring a leak.

Another thing you should notice in a properly waterproofed basement is the sound of your sump pump running. A sump pump might well be submersible, with it situated in a pit dug into your basement, but you should be able to hear it running pretty regularly, probably after rain as it pumps the collected rainwater it’s protecting you from out of your basement.

The sound might be quiet or muffled, but it might come through in the same way you might hear a dishwasher or washing machine from upstairs. Basically, if you can hear the sump pump running regularly, then you can be pretty confident that your basement waterproofing has been installed correctly and continues to protect your basement.

These are the main things to look and listen out for when it comes to making sure that your basement is protected – though its very easy to say that if your basement appears dry that everything is ok.

It might be easier to spot signs that the basement waterproofing is improper, or unfit for purpose.

Read more here

Learn more about our waterproofing solutions

Why Might My Basement Waterproofing Be Improper or Failing?

A man fitting cavity drain membrane in a basement

There are plenty of reasons that your basement waterproofing might be failing, or not fit for the purpose it has been installed for, and we are going to go through the main ones below.

Remember, these are the main reasons. If you can’t find the reason that your basement might be leaking below, or you suspect that it might be something else, then please get in touch with our team. We can arrange for a basement waterproofing survey, where a properly accredited and highly experienced basement waterproofing expert can visit your property and accurately find the cause of the problem.

Request a survey

Need Help With Flooding? Call 0800 288 8660 or

Waterproofing Not Up To Regulations

Closeup of sump pump inside chamber

In the UK there are specific building regulations relating to basement waterproofing, and its imperative that if your property does feature a below ground structure that it conforms to the regulations set down in BS8102:2022.

These are the British Standards when it comes to waterproofing, and they go pretty in depth when it comes to the protection of your basement against encroaching moisture. There is plenty to go through when it comes to the official basement waterproofing regulations, but one thing you should be aware of is that the regulations state that at least two different waterproofing systems should be in place at any one time.

That means that a basement can and should make use of two different methods of basement waterproofing. This might mean the combination of Type A waterproofing (commonly known as tanking) with Type B waterproofing, which is where the materials used to construct the property itself are waterproof.

Or, more commonly, you will find that its easier to have a Type C waterproofing system installed in combination with another waterproofing system. That’s because a Type C waterproofing system is a cavity drainage system, a method of waterproofing which involves affixing waterproof membranes to your basement’s walls and floor, which are capable of collecting any leaking water and then channelling it into a fitted sump pump, which will pump the floodwater away from your basement.

Basically, if your only aware of one type of waterproofing system within your basement then you need to look into having another waterproofing system installed. This isn’t just to comply with current building regulations, but also to make sure that your basement stays dry and usable.

Failing Waterproofing Systems

Basement flooded with water

It’s all well and good to talk about failed waterproofing systems, but what are the actual signs you should look out for when it comes to improper waterproofing?

So, the first sign to look out for is pretty obvious; any signs of moisture, flooding, leaks, or other forms of moisture in your basement when it shouldn’t be.

Any waterproofing system that has been installed properly should protect your basement from any incursion of moisture, and a puddle, drip, or even a trickle of water from a wall or the ceiling indicates that the waterproofing system applied to your basement walls isn’t working correctly.

This is obvious when it’s presenting in the form of a puddle, but it might not be so easy to spot if the leak isn’t getting further than appearing as a damp patch in your properties walls. Damp is a sure fire sign that your basement is experiencing a leak, and for whatever reason the waterproofing in place is not capable of protecting the basement against it.

There are all kinds of reasons that your basement walls might develop a leak, but some are more serious than others, and may well require additional waterproofing measures to be taken. Basically, a leak in your basement doesn’t spell the end of its usability, but it might be a sign you need additional protection in the form of a cavity drainage system.

Then again, what happens if you already have a cavity drainage system and you begin to notice floods in your basement?

In this instance there is every chance that the waterproofing system itself has not been applied properly, or has developed a fault. In either case, you will need a basement waterproofing expert to look over your cavity drainage system to identify what could be wrong, as well as a solution.

However, it might not be the cavity drainage membrane itself. Instead, one sign you should look out for when it comes to improper basement waterproofing regards the sump pump. If you happen to notice signs of flooding or pooling water around the sump pit, then it may well mean that your sump pump has not been connected correctly, or has broken down in some way.

In either instance, we strongly recommend not investigating yourself unless you have been properly accredited to do so. Sump pumps are working machines, and as such shouldn’t be tampered with as there is a risk of harm if you aren’t properly prepared for sump pump maintenance.

All that being said, you can always contact a specialist if you do suspect a problem with your sump pump, and they will be able to not only identify any problems concerning connection or ongoing pump health, but also conduct any repairs or replacement you might need there and then.

Discover if Your Waterproofing is Up to the Task

Surveyor drawing plans on tablet inside a property



If you are concerned about the waterproofing in your basement, then you can always arrange for a basement waterproofing survey. Our team are experts in the discovery and treatment of basement leaks, and we are more than capable of restoring your basement to its waterproof state.

For more information you can give us a call on 0800 288 8660, or fill in the form below to expect a call back from our team.