Heavy black mould formed on house ceiling

Is Damp The Same As Humidity?

18 February 2021

Damp and humidity are two of the most common causes for complaint within a home, or any property, at any given time. These two different afflictions in a property are very similar, and there are a lot of people out there who could be forgiven for mixing the two separate factors up.

However, if you are looking to learn whether damp is the same as humidity, then this article is for you. We will run through all of the key ways in which they differ, as well as how damp and humidity can affect your home, how they are caused, how they present themselves as well as their different side effects.

What Is Damp?

Let’s start off by running through what damp is, and how it can appear in your home.

In the simplest sense, damp is the presence of moisture within your properties masonry or walls where it shouldn’t be. Now, there are a couple of different ways in which damp can affect your walls, and these lead to a few different variations of damp.

The first variation is rising damp. This is where the moisture in soil and earth around your property rises up from the ground into the walls of your building. This liquid then travels upwards, usually through capillary action based within the mortar holding the bricks together.

Capillary action is basically the ability that liquid has to flow within narrow spaces without the need for gravity. Imagine what happens when you hold a paper towel halfway in a bowl of water. The water slowly travels up the paper towel, and makes it sodden even though gravity isn’t on the side of the water.

That’s what happens with rising damp. However, there is another form of damp that can make its way into your property and cause all kinds of damage, and it’s called penetrating damp.

Penetrating damp is usually the cause of faulty masonry, a defective sump pump system, or even degrading building works. Penetrating damp is usually the result of one of these failures, as it is characterised as liquid or moisture entering your property via the masonry directly.

This could be via something like an overflowing gutter not draining correctly. This would result in water cascading down the side of a property and the inevitable stream of water flowing down the side of the property and penetrating into the bricks and mortar.

The same kind of problem could happen with damaged masonry, missing roof tiles, improperly installed windows, or any kind of construction defect that essentially allows water into the masonry.

Even older, more porous brickwork could be a leading cause of damp in your property, so be sure to keep an eye on the state of your brickwork to make sure that it isn’t suffering from the effects of penetrating, or rising damp.

What Is Humidity?

So, now that I’ve talked through what damp is, let’s run through what humidity is and how it differs from damp.

The first thing to understand about humidity is that it’s an entirely controllable problem, and one that is usually caused by those using or living in the property itself. The simplest way to explain humidity is that it is essentially condensation; damp, humid air that builds up within a property that has nowhere to escape to, and inevitably comes to rest on surfaces within the interior of your home.

Now, this can happen for a number of reasons. A broken extractor fan in a bathroom not venting the humid air out of the room safely, a cooker that isn’t well ventilated allowing a build-up of steam on the wall and ceiling close to it, or even in a gym, with lots of sweat being produced that if poorly ventilated will sit in that room until being released in the very same property.

So, what does all this mean? Well, hot, dense air is only going to stay a gas for so long. Eventually, it will condense into water droplets that form on different surfaces in the room – which is where the problems begin.

This moisture that forms on walls, on your ceiling, and on other surfaces is one of the leading causes of damp in a property.

Now it’s important to mention here that humidity and condensation by themselves do not constitute damp. Instead, it’s the steady build-up of humidity and condensation in the same place time and time again that can lead to the eventual appearance of damp, and all of the other affiliated nastiness.

And that is the crux of this article: That humidity can be the cause of damp, whereas damp is the end result.

How Are Damp and Humidity Linked?

So, now you know why damp and humidity are classified as different entities, let’s talk about the different ways in which they relate to each other.

Now, in the last section, I mentioned that whilst humidity is the cause, damp is the result. Expanding on that a little more, let’s examine how humidity can influence the appearance of damp in your home or building.

First: how humidity affects pre-existing damp. Let’s say that, for example, you have rising damp creeping up your walls that enclose a very humid room – such as a bathroom with a broken extractor fan.

You can be sure that the continued build-up of humidity and condensation within the interior of your property is going to accelerate the progression and staying power of dampness in your walls, leading to it spreading and attracting black mould much faster, as well as potentially having a quicker impact on the structural integrity of your walls.

The same would happen in a penetrating damp situation. Imagine that you own a basement that hasn’t been properly ventilated or waterproofed, and thanks to pressure from water collecting in the surrounding soil, now has cracked walls and is allowing water in from the outside.

The rising level of humidity and condensation on the inside of the basement is going to accelerate the penetrating damp coming in from outside, weakening your basements walls in areas that are already going to have been weakened from the water ingress from outside.

The point here is this: if you already have damp in your walls, and have a condensation problem in your home that you aren’t addressing, then the condensation and humidity levels are only going to make the dampness that is already present spread faster and gain a tighter hold on your walls.

What Can Damp and Humidity do to a Property?

So, you know that damp and humidity are intrinsically linked, but combined, what is their effect?

Well, first off let’s examine what damp can do to the property itself. If you weren’t already aware, then the presence of water in your masonry is a very bad thing. The saturation of both brick and mortar can cause the materials to degrade, ultimately crumbling and potentially damaging your wall to the extent that it needs to be repaired or even replaced.

Obviously, this is dangerous. But what might pose a more immediate threat (and what you may notice first if you haven’t inspected your outer brickwork in a while) is the effect that damp and humidity can have on your interior walls.

What you need to understand about humidity, condensation and damp is that when combined they form the perfect environment in which black mould can grow. Black mould if you weren’t aware, is a nasty fungal growth that comes about when the black mould spores land on a patch of damp in a humid, warm environment, which then grows into a spotty, moss-like fungus.

This fungal black mould comes complete with a range of problems. Not only is it going to look awful in any room it inhabits, but you are also going to find that it ruins plasterboard, peels wallpaper, cracks paint, can completely ruin wood and other supports, and to top it all off, it can even pose a threat to your physical health.

Essentially, whilst humidity on its own isn’t enough to warrant a substantial threat to your property, built up over time to the point where there is a regular condensation build-up, or combined with damp? You could be in for a real problem.

How to Get Rid of Humidity and Damp

Realistically, these problems are major, but they can be solved. Let’s start by talking about humidity.

Humidity in any property is usually caused by the lifestyle of those within the home or building. Realistically, humidity builds up because of actions taken (or not taken as the case may be) by individuals more than any other reason.

If you notice that there has been a steady build-up of humidity in your home or whatever property you are concerned about, take a moment to check the room in which you are having the problem, and ask yourself the following questions. Is the room well ventilated? Are there any appliances in the room that could be causing the humidity and condensation to build up? And what actions could you take to reduce the humidity and condensation levels in the room itself?

As for the first two, that’s up to you to decide, but as far as actions you can take there are a few options available. Firstly, improve the circulation of air in the room itself. Even opening up the windows and doors of the room is going to provide a short-term solution until something more permanent can be installed.

What can be installed though? You have a few choices here. You could look into something like an extractor fan being installed, which will be capable of extracting the humid air out of the room instead of letting it sit and seep into the walls and other surfaces, or you could look into a wider solution like a positive pressure system.

A positive pressure system acts as a circulatory fan for your entire property, usually sitting in your loft and pumping fresh, dry air through the entire home or building as and when you need it – it can even be piped into specific rooms, depending on your needs. This will provide a comprehensive solution to your entire property when it comes to eliminating the build-up of humidity and condensation, and is very easy to install and maintain.

Otherwise, the use of dehumidifiers can always help in the reduction of moisture present in the air within your property, but they won’t eliminate the problem entirely. Make sure that alongside any other professional installations within your property, you examine your lifestyle and see how it could be affecting the humidity level in the building itself.

When it comes to treating damp though, there is only one real, comprehensive solution: call in our expert surveyors and technicians at Timberwise. Our team members are PCA approved and professionally trained to not only identify how and why you have damp in your home, but also on the best course of action to remove it, and stop it from happening again.

This could be through the installation of a damp proof course, through the application of waterproofing materials – or even identifying a source of humidity and condensation that you missed yourself.

For true piece of mind, be sure to give the team a call today on 0800 288 8660 for some free advice, and to see about getting a locally based surveyor out to inspect your property to remove the threat of damp as soon as possible. You can also check out our blog on the differences between condensation and damp.