Preventing damp/mould over winter

[Condi]

The caravan is getting damp over winter, and mouldy in places. I have usually had the roof vent open, trying to keep air moving and to keep temperatures inside and outside roughly equal to prevent damp, however this is clearly not working.

Next plan is to put a header and/or dehumidifier in once I get some electric to it.

Can anyone suggest what temperatures and humidity levels are likely to be acceptable to prevent mould? I have got a thermostat and humidity switch, so can set them to come on at given levels, but I was thinking maybe 8 degrees and 60/70% humidity? Or is there a better way to do it?

[donaircooleone]

Has it got any water ingress ongoing or new?

All vents and high/low level drops clear? We are seeing a fair number of 'vans where customers think blocking these are a good thing (it is not).

They don't generally get damp / mould build up when laid up appropriately.

[Condi]

I think its just moisture in the air coming in via the open top vents, and then condensing. Maybe when it rains there is some which splashes in via the vents, or blows in. Am pretty sure its fundamentally dry.

Sounds as if the obvious thing is just to close the vents, but then there wont be any air in it at all.

[DirtyHands]

Airflow is key. Make sure all high level and floor level vents are unobstructed. I also recommend having a window or two left on the vent latch. Winter covers normally make problems worse as the restrict the free flow of air.

[missing the VR6]

We have a couple of those £1 moisture collector things from Poundland or wherever, seem to be doing a good job so far in our nearly 5 year old motorhome.

[E-bmw]

missing the VR6 said:

We have a couple of those £1 moisture collector things from Poundland or wherever, seem to be doing a good job so far in our nearly 5 year old motorhome.

I am going to ask a stupid question here, how do you know they are doing a good job?

I say that because as has been pointed out above these things have natural vents that if all clear & accessible there shouldn't be any damp/mould issues anyway.

Personally, I would (as others have) simply recommend lifting all seats, opening doors and allowing natural ventilation to do what it has been designed to do.

My only addition would be perhaps one window on each side on the slightly open setting.

[missing the VR6]

E-bmw said:

missing the VR6 said:

We have a couple of those £1 moisture collector things from Poundland or wherever, seem to be doing a good job so far in our nearly 5 year old motorhome.

I am going to ask a stupid question here, how do you know they are doing a good job?

I say that because as has been pointed out above these things have natural vents that if all clear & accessible there shouldn't be any damp/mould issues anyway.

Personally, I would (as others have) simply recommend lifting all seats, opening doors and allowing natural ventilation to do what it has been designed to do.

My only addition would be perhaps one window on each side on the slightly open setting.

No idea, but the van is a 2021, bought in 2022 and has an annual hab check and the moisture reading is always very low, the moisture things always have water in them, so I guess they do something. Due to my wife's health from August 24 to December 25, we didn't the van and it just sat in storage, so never really got aired out except for the odd drive I took it on to maintain the battery etc.

I take the low moisture reading as a positive sign and they probably work, as when we were looking to buy, all advice I got was check for damp, double check and then triple check again.

[E-bmw]

missing the VR6 said:

E-bmw said:

missing the VR6 said:

We have a couple of those £1 moisture collector things from Poundland or wherever, seem to be doing a good job so far in our nearly 5 year old motorhome.

I am going to ask a stupid question here, how do you know they are doing a good job?

No idea, but the van is a 2021, bought in 2022 and has an annual hab check and the moisture reading is always very low, the moisture things always have water in them, so I guess they do something.

Literally all they do is absorb ambient moisture in the air, they will do nothing for moisture/damp in the fabric of the van.

ETA.
Aren't caravans like most motorhomes now? Full plastic construction, no wood in the structure.

It has been the case with Autotrail since about 2016 & I believe many have now followed suit.

[missing the VR6]

E-bmw said:

Literally all they do is absorb ambient moisture in the air, they will do nothing for moisture/damp in the fabric of the van.

ETA.
Aren't caravans like most motorhomes now? Full plastic construction, no wood in the structure.

It has been the case with Autotrail since about 2016 & I believe many have now followed suit.

This is certainly not my field of expertise, but surely moisture in the air would then get into the fabric of the van? I may well have completely misunderstood though.

No idea what the van is made of, in all honesty didn't give it any thought, was just happy it had 7 years ingress warranty left, was automatic, had the right layout/spec and was under 3.5T.

[E-bmw]

missing the VR6 said:

E-bmw said:

Literally all they do is absorb ambient moisture in the air, they will do nothing for moisture/damp in the fabric of the van.

ETA.
Aren't caravans like most motorhomes now? Full plastic construction, no wood in the structure.

It has been the case with Autotrail since about 2016 & I believe many have now followed suit.

This is certainly not my field of expertise, but surely moisture in the air would then get into the fabric of the van?

I do know many people use them & while they will remove humidity from the air, it is only from the air that actually comes into contact with the "crystals".

I have a "weather station" at home it shows inside as well as outside "weather conditions".

With all doors/windows closed the humidity doesn't constantly drop while the humidity leaves the air & enters the fabric of the house.

The humidity goes up & down constantly.

Do you use these "air driers" in your house?

I also have a tracker on my motorhome, it also transmits internal and external conditions to an app on my phone. The internal humidity also goes up & down with the air that is circulating within the van.

ETA.
That is the way I see it anyway.

Edited by E-bmw on Friday 22 May 17:07