Condensation cabin roof.

[windlipper]

My cabin headlining is vinyl covered plywood boards. Boat has been unoccupied for a couple of weeks and there is now quite a bit of wet on the inside of the GRP behind the boards. Can’t find any sign of water ingress from outside. Can this be condensation even though no heating inside the boat? Boat is in the uk.

 

[syvictoria]

Are the bilges dry? Any volume of water can result in condensation if given an opportunity to warm up, even in the UK in winter. We've had a lot of variation in air temperature of recent.

 

[Momac]

Can this be condensation even though no heating inside the boat? Boat is in the uk.

Yes. Why not?

 

[windlipper]

Are the bilges dry? Any volume of water can result in condensation if given an opportunity to warm up, even in the UK in winter. We've had a lot of variation in air temperature of recent.

No water in the bilges, wondered if contrast between very cold and sun warming of the deck may be responsible.

 

[Moodysailor]

Most likely, yes. We've had unseasonably mild days combined with very high levels of humidity so it stands to reason.

 

[syvictoria]

No water in the bilges, wondered if contrast between very cold and sun warming of the deck may be responsible.

Check ALL of your lockers too. Water from a random/occasional leak can sometimes make it into unexpected places! Assuming that the boat is ordinarily dry, my own experience is that in general it is water in an unoccupied boat that results in condensation, as opposed to 'just' atmospheric air humidity.

 

[ctva]

Is your boat 'sealed' or is there good ventilation? There is a large amount of water in air which needs heat / ventilation to remove.

We've successfully used a small solar vent for years, makes a big difference.