hi Joan
I noticed that you said you might be doing some winter trips. We have a Troll 540 and it has always been OK in terms of water coming in (touch wood) until one night in York last winter when it was below freezing. I was woken up by water dripping on my head and thought that the roof or the side material was leaking. However when I got up and turned the lights on I could see that the bottom aluminium rail on the roof was running with condensation. I went round it all with kitchen roll and used a load of it..
Talking with people on the Forum many drop their roofs if it is below freezing. I also think that we had been in the van for quite a bit before we went to bed and had lots of heating on and probably put a lot of water in the air, which condensed when it hit the cold aluminium. I think in future when it is freezing I will knock the heating off and then wipe the aluminium down and then shut the roof.
It makes me wonder what effect the new Hymer/Eriba insulation for the canvas popup sides may have on the condensation problem. Happy camping MikeT

The burning of any combustible product in an enclosed space without adequate ventilation is inviting condensation. Add to the atmosphere exhaled breath and one is inviting problems big time. What is required is low background DRY heat such as from an oil filled radiator set at a comfortable level in addition to cross ventilation. Condensation on the pop-top roof is visible and easily mopped up, it's the build up of damp in hidden areas that can cause major damage hence the annual damp test.

Hi Deeps. I'm not very technically minded - in your view would lowering the pop-top roof in below freezing conditions have any effect on reducing the build up of condensation on the lower metal strip?

I wonder how many Forum members do actually put their roof down in freezing conditions or perhaps use some kind of insulation like Poptop320 has done. It would be interesting to know MikeT

No, best left open. It might go against the grain but leave the vents half open unless rain is really driving in. Like I said earlier, warmth (preferably dry) with cross ventilation is the only way to keep things dry.

Thanks Deeps - will give it a whirl and see how far it reduces the condensation in our Troll in winter. MikeT