There is a topic which strikes fear into many caravanners, damp in a caravan. And rightly so, damp can destroy the fabric of a caravan leading to either costly or irreparable damage. However, it also creates an unhealthy living environment with the potential of toxic black mould. Therefore, it’s very important to check for damp on a semi-regular basis with a caravan moisture meter. Now, if you take your caravan in for an annual or bi-annual service a damp test should be completed as standard. However, some of our guests have questioned how extensive service centre damp tests are. Therefore, for additional peace of mind, it’s not a bad idea to have your own caravan damp meter to conduct your own tests.
There is a wide range of moisture meters you can use to check for damp in a caravan – Image: Amazon.co.uk
Disclaimer: Hey! By the way… any links on this page that lead to products on Amazon or Caravan Guard are affiliate links and I earn a commission if you make a purchase, with no additional cost to you.
With this post, I’ll discuss damp meters which can test the moisture content of surfaces and materials. However, I’ll also discuss the use of humidity meters and how to interpret their results. This is quite a long post, so you can use the Table of Contents below to jump to particular caravan moisture meters.
Caravan Moisture Meter Results
Before we look at specific products you need to be able to understand what the results are telling you and how to interpret them. Typical moisture meters used to test for damp in caravans are the pin type. An electrical charge is passed between the two pins when in contact with a surface. The more moisture present, the easier it is for the electrical charge to pass between the two pins. The result is expressed as a percentage (%) of moisture within that material or surface between the two pins. Hence, the result is location-specific. Below is how you should interpret the percentage results.
- 0 – 15%: The surface is dry, no damp present.
- 15-20%: Make a note of the area, check again in a few months.
- 20-25%: Area needs further damp investigation.
- 25-30%: There would appear to be water ingress into the caravan.
- Above 30%: Immediate action needs to be taken.
How Accurate are Caravan Moisture Meters?
The type of products discussed below are all ‘consumer-grade’, in other words, they are affordable but cannot be regarded as particularly accurate. It’s not uncommon for these affordable damp testers to return a result which varies 2% or potentially more from the actual moisture percentage. Also, the conditions and humidity at the time of your damp test can impact the results. For instance, if its a particularly humid or rainy day. Those conditions will evaluate the percentage results slightly.
Therefore, with these cheap caravan damp testers don’t instantly panic with a result between 15-20%. Make a note of the area of concern and make a note of the current weather conditions. If it is a rainy day or a day with high humidity try and test that area again on the next dry day. As these affordable caravan moisture meters are not accurate to a professional standard if you do identify a potential problem area it may be a good idea to have that area tested again by a caravan technician. That way before you have any expensive work carried out it can be more accurately determined if there is actually a problem.
Caravan Moisture Meters for Damp Testing
Below is a selection of products you could consider to carry out your own damp tests on your caravan. There are many portable moisture meters available. The selection below is just a couple of options.
Brennenstuhl Moisture Meter
The Brennenstuhl moisture can be used to test for damp within your caravan or motorhome. It’s suitable for hard wall and surface materials. Excessive force during testing is not required and could damage the moisture meter or your surface. The Brennenstuhl product can measure the moisture content of your caravan surfaces between 5-55%, with a 0.1% result. It’s powered by a 9V block battery. The precision of this moisture meters is quoted as +/- 3%.
This Brennenstuhl moisture meter is a typical example of a product which can be used to check for damp in a caravan or motorhome – Image: Amazon.co.uk
The hold function on this particular moisture meter could be particularly useful when trying to test those hard to read areas where you cannot see the screen.
Brennenstuhl Moisture Meter Features
- 5-55% Moisture Readings with a 0.1% resolution
- Accuracy: +/- 3%
- Power: 9V Battery
Stanley Moisture Meter
I’ve included this Stanley moisture meter to test for damp in a caravan as I personally do like Stanley products. I’ve used a range of their measuring and levelling products in the past when I built my home. However, disappointingly with this moisture meter, Stanley has not stated the accuracy tolerance. While it’s likely to be within the +/- 3% range of the Brennenstulh, we just don’t know. The range of the Stanley moisture meter is between 6-44%.
The Stanley moisture meter has a range of between 6-44% – Image: Amazon.co.uk
Unlike the Brennenstulh the Stanley moisture meter does not use a single 9V battery, but a set of 4 x AAA batteries. Again as mentioned above, don’t push the pins too firmly into the surface, just allow for good point contact. Then give the moisture meter a second or so to provide a result.
Stanley Moisture Meter Features
- 6-44% Moisture Readings
- Accuracy: Unknown
- Power: 4 x AAA Batteries
Proster Damp Meter
So the last product I wanted to reference is from Proster. The reason being is that it appears to be the most affordable and most accurate currently available at the consumer level. The Proster features a material selection mode and a measuring range of between 0-99%. It also apparently has an accuracy of 0.5% which if true is very impressive.
The Protest damp tester apparently has an accuracy of 0.5% – Image: Amazon
Now, the 0.5% accuracy of the Protest does need putting into context. As that accuracy will only be the case when the material being tested exactly matches the chosen mode. Therefore, that accuracy does not necessarily translate to measuring the various surfaces within a caravan. If you can when you take your caravan in for a service ask if the technician can compare your moisture meters modes/results with their professional-grade equipment. That way you will know how accurate or inaccurate your chosen moisture meter is when it comes to caravan materials. Furthermore, you may find a specific mode will produce the most accurate results with caravan or motorhome interior materials.
Proster Damp Meter Features
- 0-99% Moisture Readings
- Accuracy: 0.5%
- Power: 9V Battery
Pinless Moisture Meters?
So, not surprisingly the idea of sticking pins into the various surfaces of a caravan is not appealing to many people. They don’t want to scratch or damage the walls of their caravan or motorhome. So can you get pinless moisture meters to check for damp? Yes, but the general consensus online and from some of the guests to our caravan site is, they are not accurate enough.
Unfortunately, affordable pinless moisture meters to check for damp in a caravan or motorhome don’t appear to produce accurate results. – Image: Amazon.co.uk
There are high-end pinless moisture meters that I’m sure are fairly accurate, but that doesn’t appear to be the case at the consumer level. Therefore, for your average caravan or motorhome owner, pin type moisture meters to check for damp are currently the only practical option. You just need to be careful and take your time to avoid surface damage from the pins.
Caravan Humidity Meters
So above we have discussed moisture meters to check for damp in a caravan or motorhome. Those products are used to check for moisture within the materials or the caravan. However, there is another way to measure moisture within a caravan, using a humidity meter. Humidity is moisture within the air. Therefore humidity levels are highly dependant on the time of day and weather conditions. Its also significantly influenced by the activity within the caravan. For instance, breathing raises the humidity, and boiling a kettle will significantly raise humidity within a caravan. A humidity meter displays the result as a percentage of moisture within the air.
Using humidity meters within a caravan cannot be used to specifically indicate if there is a damp issue. A humidity meter can also obviously not identify the location of the damp issue if there is one. However, they can provide a prompt for when further damp investigation with a moisture meter may be required.
ThermoPro Humidity Meter
An affordable humidity meter you may want to consider for your caravan or motorhome is the ThermoPro. The reason being is that it displays the lowest and highest humidity recorded. Therefore, while your caravan is in storage you could leave the ThermosPro on and it will tell you what the maximum was within the caravan.
The ThermoPro displays the lowest and highest humidity percentage recorded – Image: Amazon.co.uk
Before you put your caravan into storage you could use a dehumidifier for a couple of days to make sure the furnishings are dry and not holding moisture. You could then leave the ThermoPro running in your caravan or motorhome. When the caravan or motorhome is in storage and not in use a humidity reading over 50% may indicate a damp issue. Therefore, if the max humidity reading was above 50% you would then want to get your moisture meter out and start investigating.
UniBot WiFi Humidity Sensor
Now, if you like your gadgets and you like a Smartphone app you could even consider the Unibot humidity sensor. This small little box runs on 2 x AA batteries which can last for 4-6 months. Hence, you shouldn’t have to change the batteries while your caravan or motorhome is in storage. It sends temperature and humidity information to your phone in realtime and the data is also stored on a graph.
The UniBot WiFi humidity sensor can be set up to provide an instant alert you if the humidity of your caravan or motorhome in storage goes over 50% – Image: Amazon.co.uk
With the Unibot humidity sensor, you can set specific alerts. Therefore, as we have discussed above, you could set an alert if the humidity in your caravan or motorhome goes over 50%. The advantage with the Unibot compared to the Thermopro is you will be instantly be made aware of any potential damp issue developing.
Conclusions on Caravan Moisture Meters
The key to stopping damp destroying the fabric of your caravan or motorhome is to be able to address the issue as quickly as possible. Therefore instead of just relying on your service company to carry out damp tests, its also a good idea to have your own moisture meter. With a suitable moisture meter, you can check for damp around your caravan or motorhome. Problem areas may typically be around windows, doors and any ports or vents.
When it comes to humidity meters they cannot tell you specifically if there is a damp issue or where a damp issue may be coming from. However, what they can do is provide an indication when a damp investigation with a moisture meter may be required. I hope you found this post on moisture meters and damp testers useful. I also hope you consider coming to visit use at Horton Common at some point. 🙂