Hull Insulation/Condensation Prevention

[Parisina]

Hello,
I am in the process of acquiring a Vagabond 47 and will be subsequently moving aboard it year-round starting in April. My question was recommendations for types of insulation, methods, and placement of it? I read that if there are portions of the hull cored that it does not need insulation, how does one determine if it is cored? Thank you for your time.

[boatpoker]

Originally Posted by Parisina

Hello,
I am in the process of acquiring a Vagabond 47 and will be subsequently moving aboard it year-round starting in April. My question was recommendations for types of insulation, methods, and placement of it? I read that if there are portions of the hull cored that it does not need insulation, how does one determine if it is cored? Thank you for your time.

The Vaganond has plywood cored deck but the hull is not cored. Your surveyor should have told you that.
Where will you be living aboard ? Florida ? BC ? Ontario ? NY ?

[GordMay]

Originally Posted by boatpoker

The Vaganond has plywood cored deck but the hull is not cored. Your surveyor should have told you that.
Where will you be living aboard ? Florida ? BC ? Ontario ? NY ?

Greetings and welcome aboard the CF, Parsina.


You can take what boatpoker says, to the bank.
Vagabond 47 Used Boat Review ~ by Jack Hornor
“... Hulls are built of solid fiberglass* and resin with a full keel and attached rudder. From what I have been able to observe, layup is mostly chopped strand* mat and about as far as you can get away from high tech. But, it’s thick and relatively strong. Hardwood longitudinal and transverse stringers and plywood structural bulkheads are attached with chopped strand mat and polyester resin and, if the structural components have not been damaged by deck leaks and water saturation, the hulls are stiff and strong...”
More ➥ https://www.spinsheet.com/boat-revie...ed-boat-review

[Parisina]

Originally Posted by boatpoker

The Vaganond has plywood cored deck but the hull is not cored. Your surveyor should have told you that.
Where will you be living aboard ? Florida ? BC ? Ontario ? NY ?

My wife and I will be living in Chicago

[boatpoker]

Originally Posted by Parisina

My wife and I will be living in Chicago

Ok, I've lived aboard since 94' and with the exception of a number of winters south have wintered aboard just west of Toronto.

You will hear all sorts of tales about horrendous humidity and condensation resulting mould and the need to run dehumidifiers. I don't know anyone among my liveaboard friends here that have experienced that. In fact as I write this my HUMIDIFIER is running full blast.

Proper ventilation and good insulation are key. The Formosa being a stick built boat should be fairly easy to insulate. We have used a mix of blue foamboard and Rockwool. neither absorb moisture.

Many who attempt insulating boats forget a crucial element ... Vapour Barrier ! The vapour barrier must be air tight. If air is circulating between the hull and the insulation you will get mold.

[rbk]

Originally Posted by boatpoker

Many who attempt insulating boats forget a crucial element ... Vapour Barrier ! The vapour barrier must be air tight. If air is circulating between the hull and the insulation you will get mold.

Yes and no. Insulating a hull is very similar to insulating a concrete basement in northern regions with the exception that the hull is also a vapour barrier and having two can be worse as it will can trap moisture between the two impermeable layers. If there is an air space between the hull as BP describes above yes that is also bad as it creates a surface for water to condense on. Really what you need to do is create a temperature gradient that moves the dew point away from a condensing surface (the hull) and put the dew point within the insulation so liquid water does not have a surface to condense on. Ensure the insulation is well bonded to the hull and either seal up the interior with a proper vapour barrier with absolutely zero leaks or forego the VB and let the insulation breath. Mineral wool products are a great option as are closed cell spray PU foam. Should note that closed cell foam does not absorb water as compared to an open cell sprayed foam, most people confuse the two.

[noelex 77]

Cored fibreglass only provides a tiny bit of insulation. It is better than solid fibreglass from an insulation perspective, but it is still relatively poor.

If you are planning to cruise cold or hot climates, if it practical to do so then additional insulation will make a significant difference to the comfort.

People often think of luxury cruising as a boat with many gadgets, but a dry boat free from condensation and mould that is cool in hot weather and warm in cold weather, and importantly has no leaks, is the first fundamental requirement that is often neglected.

[Shrew]

Originally Posted by Parisina

Hello,
I am in the process of acquiring a Vagabond 47 and will be subsequently moving aboard it year-round starting in April. My question was recommendations for types of insulation, methods, and placement of it? I read that if there are portions of the hull cored that it does not need insulation, how does one determine if it is cored? Thank you for your time.

Foam cored, maybe. Balsa (wood) cored, doubtful.......and about as effective an an uninsulated garage or shed. I've never seen a foam cored deck.