In our latest article, we explain what humidity is, why high and low humidity levels are bad for your house and what can be done to control it.
What Is Humidity?
So, what exactly is humidity? Humidity simply put is the amount of water vapour that is in the air. The warmer the temperature the more water vapour is held in the air.
What is the Ideal Humidity For a Room?
There are different recommendations on what the ideal humidity level should be inside your property, however, it does also depend on the time of the year e.g. Summer or Winter. Our recommendation would be to have your house humidity levels between 30-60%.
What Causes High Humidity in a House?
There are a number of factors that can cause your house to be humid. One of the biggest factors that produces humidity in your property is that the air does not circulate as it should. This usually occurs in winter when people turn the heating on with the additional factor of closing the doors and windows to keep the air in.
Moisture can find its way in during periods of rain and snow into the property if there are cracks inside the building. Carrying out day to day activities such as cooking and bathing also increase the humidity levels in your home.
Why Are High Humidity Levels a Problem for Your Home?
If the humidity levels rise above the ideal humidity level for a home problems can start to arise within your property. Having high humidity levels is a problem for houses across the UK as it causes moisture and condensation to build up which in turn leads to more serious problems such as wood rot and black mould. We have listed below the potential problems resulting from having high humidity levels in more detail.
Mould and Mildew Growth
When the humidity levels are above 60% this provides the perfect conditions for mildew and mould to grow. Mildew is a white or grey organism that tends to grow on surfaces such as shower curtains or windowsills. Mould is often black in appearance and is harder to eradicate than mildew as it doesn’t remain on the surface but can damage any part of your house e.g. the walls.
If black mould growth is not controlled, then it can destroy any of your household items such as carpets or soft toys. If the house has a serious case of mould, this can then cause serious damage to timber frames and windows, which could eventually mean the structural integrity of the building could be at risk.
Mould in your property isn’t just bad for the property but also for your health as well. If you have damp and mould conditions within your house, then you are putting yourself at risk of having respiratory problems such as asthma.
Paintwork Damage and Peeling Wallpaper
The interior walls of a building are a prime location for condensation to build up. If condensation has started to affect the walls, then the wallpaper will start to peel off the walls and you will have flaky paint – this is a sign of dampness.
You cannot deal with excess moisture in your home by simply painting over the walls, you need to deal with the source of the damp problem. It is important to note that wallpaper peeling off the walls is not just as a result of having condensation problems but other damp issues as well such as penetrating damp.
To make sure the damp problem is correctly identified we would recommend having a survey from one of our qualified surveyors at Timberwise.
Wood Rot on Timbers
When there is excess moisture in the air, it can damage timber which may start off just as a few stains but then over time can lead to serious decay. In the most serious cases of dry rot, it needs moisture content of over 20% to germinate in the timbers. When this happens, it can spread to further parts of the building causing serious damage to the house and the contents affected.
Why are Low Humidity Levels a Problem for Your Home?
While most people often think that high humidity levels for houses are a problem, which as we have just explained, they are, having low humidity levels is also a problem too. If the humidity levels drop below the recommended level of between 30% and 60% this can have an effect on your health which can include people having dry eyes and dry skin.
Having low humidity levels can also cause damage to your property. Wood does contain some moisture and if this dries up, the timber can start to shrink, this is when serious damage can occur.
How Do I Control the Humidity in My House?
While there are a number of problems associated with both high and low humidity levels, there are simple steps you can take to maintain the humidity levels at a comfortable and recommended level of between 30%-60%.
Controlling High Humidity Levels
When you carry out daily activities such as taking showers, cooking or even breathing then these generate moisture. One of the first steps for reducing the moisture in the property is making sure the house has good ventilation throughout. Simple measures you can take are by simply opening windows, using extractor fans and air conditioning. You should be using these methods of ventilation in rooms where humidity levels are at their highest such as: bathrooms, kitchens and bedrooms.
If you are using the shower, then make sure the extractor fan is on before and after you leave the bathroom to make sure the humid air is fully circulated. Opening your windows in the bathroom as well will help with ventilation. When cooking, you should have ventilation hoods turned on to make sure that the air is circulated fully.
One of the main causes of condensation occurs when warm air lands onto a cold surface. This can be resolved by having the house maintained at a regular temperature. This lessens the chances of warm air landing onto a cold surface.
For a short term solution, you can also use dehumidifiers as a way to extract moisture from the air. They are mainly used in basements where the less circulates less.
Controlling Low Humidity Levels
If your property is suffering from low levels of humidity, then installing air conditioning is one of the best solutions to getting the conditions at the right level. To increase humidity levels, you can also let the warm air out of the showers by opening the door.
If you air dry clothes indoors then this will increase the humidity as well. Make sure you don’t overdo this though, or you will have the same problem of having high humidity levels.
Important Things to Remember Regarding Humidity
We hope this article has provided you with a clear understanding of what humidity is, the problem with either high or low humidity and methods of how to control it. The key things to remember about humidity is that both low and high humidity levels can have an effect on your health and your house, if not dealt with soon enough. There are also simple steps at home you can take to make sure you have the right humidity within the property and these mainly stem from improving ventilation.
If you have questions about issues with humidity and condensation, then contact our team on 0800 288 8660 or contact us online.
FAQs
What is the Ideal Humidity Level in a House?
The ideal indoor humidity level is generally between 30% and 60%. Within this range, the air is comfortable for occupants and less likely to cause condensation, mould growth, or timber decay. Levels above 60% increase the risk of damp-related issues, while consistently low humidity can lead to drying and shrinkage of wooden materials.
What Causes High Humidity in a House?
High humidity is usually caused by excess moisture being produced indoors and insufficient ventilation. Common sources include cooking, showering, drying clothes indoors, poor airflow, and inadequate extraction. External factors such as rain penetration or structural defects can also contribute, particularly where moisture enters through the building fabric.
Why is High Humidity a Problem in Homes?
High humidity increases the likelihood of condensation forming on cold surfaces, which can lead to mould growth, peeling paint, damaged plaster, and timber decay. Over time, this can affect both the condition of the building and indoor air quality, particularly in poorly ventilated rooms such as bathrooms, kitchens, and bedrooms.
Can High Humidity Cause Damp and Mould?
Yes. When humidity levels remain high, excess moisture in the air can condense on cold surfaces, creating ideal conditions for mould growth. Persistent damp environments can also contribute to deterioration of plaster, wood, and insulation materials if the underlying cause is not addressed.
How Do You Control Humidity in a House?
Humidity can be controlled by improving ventilation, reducing indoor moisture generation, and maintaining consistent heating. This includes using extractor fans, opening windows where appropriate, avoiding excess indoor drying of clothes, and using dehumidifiers in problem areas. If humidity remains high despite these measures, a professional assessment may be needed to identify underlying damp issues.
