How to Stop Condensation in a Motorhome

It’s a fact that your motorhome is vulnerable to moisture, as damp and mould can damage the fixtures and fittings. In the worst possible scenario, moisture and its effects can compromise the structural integrity of the vehicle, leading to costly repairs. On the upside, the build quality of motorhomes is improving exponentially as new technologies and systems develop, so protective measures get better year on year. However, on the downside damp is a natural phenomenon so will always exist – and is, therefore, always likely to occur and pose a threat, so it needs to be considered. In this blog we will look at how to stop condensation in a motorhome.

If your motorhome has faulty seals at any doors, windows and roof lights, it’s likely that water will be able to drip or leak, seep or drip in. The vehicle’s structural seals where there are construction joins can also be a point of water ingress if compromised due to having been fixed with inefficient low quality sealant. Even minor leaks can lead to serious structural damage. If you don’t do anything about these issues as and when you find them you are basically storing up problems which can only get worse.

It’s not all about the physical structure of the motorhome, either. The air itself causes problems. Damp often manifests as mould if there is not enough ventilation and condensation is allowed to build up inside the vehicle. Probably the clearest recurring visible indicator of it is motorhome windscreen condensation.

There are tell-tale signs that moisture is causing problems in your motorhome. They are as follows:

1. Mould spots: Inadequate air circulation will encourage mildew and mould growth, especially in colder conditions. The presence of black spots around windows or on roof lights signifies the need for urgent inspection. Also check in areas where air gets trapped – down the side of your mattresses, behind cushions etc. If you find mould stains there, then it is likely that there is a problem and condensation is happening. The cycle of cleaning these areas over and over is a quick fix, but not a solution.

2. Spongy surfaces: If the walls of your motorhome feel a bit softer than they should, and if they yield under any pressure, it’s likely that there has been some moisture infiltration. You are likely to need professional intervention to rectify the problems and pinpoint airflow problems.

3. Musty and stale smell: A dead giveaway that you have moisture problems is that the interior air doesn’t smell fresh or pleasant, and has a musty odour. Though it will probably be subtle initially, the smell will intensify over time, which is an indication of dampness within the vehicle.

Condensation occurs in enclosed spaces when warm air comes into contact with colder surfaces (i.e. windows and walls). Due to temperature differentials and moisture in the air it quickly cools down, leading to water vapour condensing into liquid water. In a motorhome the physical area is much smaller and enclosed than in bricks and mortar homes, and so factors such as kettle boiling, cooking, showering and even breathing mean moisture.

Conducting routine inspections of the motorhome’s exterior for signs of leaks or water damage is crucial for preventing moisture-related issues. Promptly addressing any problems or areas of concern will help to maintain the integrity of the vehicle and prevents moisture from invading the interior. It is also a good idea to take advantage of Lowdham’s facility to conduct habitation checks and services. In addition to moisture testing, the habitation service consists of a multi-point check which includes gas pressure and soundness, electrical systems including 12V & 240V and a water systems check. There are preventative steps or practical solutions to stop condensation in a motorhome – or, at the very least, do your best to tackle it.

Swift action at the first sign of condensation will help mitigate further damage and save you money in the long run. It’s important to have proper ventilation, insulation and temperature management inside the motorhome, and there are other steps that you can take. They include:

1.  Ventilation: If there is insufficient ventilation then moist air gets trapped inside – the ideal condition for condensation. Making sure there are adequate ventilation systems (such as roof vents and extractor fans) will help to prevent the build-up of moisture in a motorhome. Air can circulate, which reduces the likelihood of dampness and condensation forming on surfaces. Simple steps, when cooking or in the shower, such as opening windows will also be a help in moisture control.

2.  Absorbers: Absorbers are products which been specifically designed for the task of absorbing moisture. There are several different products on the market, though there are reports which suggest that BirchSorb is particularly effective due to the amount of moisture it can handle with no leak or rerelease. Using absorbers can effectively reduce excess moisture in confined spaces and help maintain a drier environment – including motorhomes. Using absorbers in areas particularly prone to the effects of dampness (wardrobes and storage compartments), helps maintain a drier environment.   3.  Insulation: Well-insulated walls reduce the chances of warm, moist air inside the vehicle coming into contact with cool surfaces. Therefore, ensuring there is adequate insulation within the motorhome’s walls, floors and ceiling will go some way to preventing the temperature differentials which lead to condensation.

4.  Heating: Most modern motorhomes have heating systems integral to their build, but if yours doesn’t then ensuring there is some form of heating (e.g. diesel heater or electric radiators) will help to regulate the interior’s temperature. This will, therefore, reduce humidity levels inside the motorhome and discourage condensation from forming, particularly during colder months or in regions with high humidity.

5.  Avoiding wet: Be careful not to bring damp or wet items into the motorhome as, effectively, you are bringing excess water onboard, and that will contribute to moisture build-up. If you need to dry clothes, shoes and outdoor gear after (say) a day at the beach or in the lake, then do so outside as this helps prevent the introduction of excess moisture. Keeping the interior of the motorhome clean and dry will always help in the fight against moisture issues. The Lowdhams Accessory Store (at Nottingham) has a range of products designed to help.

6.  Storage of items: Store items in a well-organised manner, as this will allow air to circulate around them, helping to prevent moisture accumulation. Don’t cram your belongings into confined spaces, as this will restrict airflow and promote dampness.

If your motorhome is in storage (perhaps for the winter) and you have no electricity hook-up running to it, but you are still suffering the problem of condensation, then it is likely that there is a leak somewhere aboard. In this case you should use a damp meter to establish where the water is coming in to the motorhome. The wall closest to the leak itself will register high damp readings on the meter, and from these you will be able to locate the exact position. Once you have this you can seal or repair the point of leak.

For a long time after you have bought a new motorhome it should not be susceptible to any serious issues caused by moisture. Essentially, you are buying a very well manufactured product which has been designed to keep you safe and problem free. In the unlikely event that there are any initial problems, new motorhomes are subject to warranty. As the length of your ownership continues, if you have your motorhome serviced regularly and conduct habitation checks any moisture-related issues should be avoidable or dealt with before they become problems. Regularly or routinely follow the steps we have described here, and you will be home and dry, as they say!