If you discover that you have a problem with damp, or in the worst case, mould, in your crawl space, it is important to first address the cause of the problem and possibly replace mouldy and damp-damaged materials. In this article, we look at what causes dampness in the crawl space and how you can solve the problem.
The cause of moisture in the crawl space can be due to a variety of reasons. Below you will find some:
Soil moisture occurs when water rises through the ground in the crawl space by so-called capillary action. This is often caused by having too dense material in the foundation that allows water to rise. To remedy this, you can replace the material with gravel with a size of 8-16. Changing the material involves a lot of work. You can also roll out construction plastic on the ground to prevent water from coming up.
If the ground around the crawl space is poorly drained or, in the worst case, the ground slopes towards the house, you will have major problems with moisture in the crawl space. Make sure that the ground slopes away from the house by at least 3 metres and that you have good drainage around the entire house.
A common cause of moisture and water in the foundation is that downpipes are not led away from the house and instead just end down at the foundation. This means that when it rains, the water eventually finds its way into the crawl space. Make sure to lead the water away from the downpipes a good distance from the house. Also make a habit of cleaning leaves from gutters.
A leaking water pipe can be difficult to detect before it is too late. The leak can be several metres from where water is dripping. Often this problem creeps up on you and causes very costly repairs.
If a large negative pressure builds up in your crawl space during the summer, hot and humid air can be drawn in from the house or outdoor environment. This warm, moist air cools down as it enters the crawl space and condenses on cold surfaces. This leads to an increase in the relative humidity, which can create an unfavourable environment for the building's construction.
Flowers around the house are beautiful, but they carry a high risk of causing moisture problems in the crawl space. When the flowers are watered, water will most likely find its way down to the crawl space and cause dampness, in the worst case with mould as a result.
Don't be intimidated by houses with a crawl space. There are many advantages to a crawl space. Above all, it is much easier to fix a fault or damage compared to cast slab.
But make it a habit at least once a year to crawl into the foundation with a flashlight and inspect the pipes and make sure that no traces of water have seeped in. Check the seam around the edge of the crawl space extra carefully for mould. The mould is often known as white mould.
📌 Reading tips: Signs of moisture damage
If you discover that you have a problem with dampness in the crawl space or, in the worst case, mould, it is important to address the cause of the problem in the first instance. Depending on the extent of the problem, you may also need to replace mouldy and moisture-damaged materials. This is often the most time-consuming and costly part of the work.
Once you've fixed the problem, it's important to prevent it from happening again in the future. By installing a crawl space dehumidifier In the illustration at the beginning of this article, you can see an example of how to install a desiccant dehumidifier in the crawl space.
However, make sure you buy a dehumidifier with an external control panel that gives you easy-to-access information about humidity and temperature. Also, make sure that the dehumidifier can alert you when it's time to change the filter and if for some reason the dehumidifier cannot keep the humidity below a safe level.
At Acetec AB, we have extensive experience of moisture solutions for crawl spaces and are happy to help you find the right product for your needs.
💡 Try our digital tools to guide you to the right dehumidifier solution - or contact our technical support for personalised advice. You can call our switchboard on (+46) 010-28 80 110.
