Insulating a Boat to Prevent Condensation

[blackrose]

One possibility is insulating a small section at a time using either Kingspan which is very good. Wadding which must be covered both sides with a vapor proof barrier. There is a super efficient material available but uber expensive. Fill any small gaps with blow foam.

Yes I think I'd take off a section of paneling at a time and stick 25mm kingspan or cellotex to the walls with marineflex.

[NMEA]

Thanks so much, all! I will bear in mind what you say about ventilation and the pic of the insulation is perfect - just what I need.

 

Does anyone know someone in London who would be willing to do this work?

If you can get the boat to South Dock then Chris Olley is a good choice, He is in high demand so I doubt he would be able to do it for a month or two, but he is skilled, reliable, works quickly and is realistically priced for London.

Edited December 20, 2014 by NMEA

[dor]

As Mustyboat originally posted their question last January, are they still around to let us know what the solution was?

[b0atman]

How did they know that there was no insulation ?

[trackman]

Having gutted the boat, I've just finished painting the bilge and sides up to the gunwale. Went to check on drying, and what I thought was a horizontal shadow line on the side turned out to be where condensation started at the water line, going down to the bottom. Don't know why I was so surprised, but explains why there was so much rust that I had to remove when starting work. The old insulation was rockwool. No vapour barrier used.

 

For the sides from gunwales down, plan to use battens and expanding foam, and then Celotex faced with ply panels. Celotex should provide the vapour barrier.

 

Yes, Celotex will, but only if there are no gaps or open joints. I'd recommend taping joints over with duct tape or similar air and water resistant tape and plugging larger gaps with sprayed foam from aerosol cans.

 

Any recommendations on foam? Looking at Soudal Flexifoam and Bond-It Megafoam.