Insulation

Unless you’re in southern California, you will probably need some form of insulation to fight the cold, heat, and condensation. You can try temporary approaches like running a heater, using a dehumidifer, or leaving hatches open all the time. However when winter hits, these solutions would need to run constantly in order to fight rain and cold. Beside being wasteful, it’s also not practical on anchor or mooring without using a large amount of fossil fuels. Adding insulation has been one of the largest upgrades to our comfort so far.

Which Insulation

We debated the most between cork and closed cell Armaflex. Cork had the benefit of being more aesthetically pleasing, and we at first wanted to avoid adding headliners due to lack of space in boat height. It’s also better for sound insulation if a little less warm. However we could only find cork in dark colors, and we were not interested in spray cork as we couldn’t find many resources. Since that time there are now good videos on the process here and here. There are also options like “Areogel” that could work under certain circumstances, but are normally too expensive. Armaflex is itself quite expensive, so very concerned with price look to another material.

As far as actually acquiring the Armaflex, it is surprisingly difficult in the US. In Europe it’s easy to acquire, but in US the only way we could get it was to drive to a Distribution International.com/b/armaflex warehouse and get rolls or sheets in boxes directly. It’s a little awkward, but they seem fine to sell small orders to individuals (if a little confused). We ordered thicknesses of 1” and 3/4” an inch depending on where it was getting installed. In Europe they sell Armaflex that is backed by adhesive which should definitely be purchased if it’s an option. It will save much more time than applying your own adhesion.

Installing Armaflex

In order to cut the insulation, be sure to buy an insulation knife, and a self healing cutting mat. We purchased the self healing cutting mat in person in order not to bend it, but that was overkill in retrospect. Buy the largest one that you can in order to not move the insulation and mat over and over. To template insulation spaces, we used butcher paper and traced with a permanent marker around the edges. This worked ok, but for complicated patterns was not a great solution. We are still considering better solutions for future insulation projects.

When cutting, we added 1/4” all the way around the butcher paper template. The Armaflex can compress a bit on all edges, so this helped to make sure there was no extra space the insulation wasn’t covering. We tried adding 1/2” all around, but this turned out to be too much, and the insulation would bulge in the middle. We then applied contact cement to the back of the insulation and the wood surface being applied to itself. You’re supposed to wait 5 minutes to apply, but we found it was best to wait only a minute or two so that the insulation wouldn’t stick in place. On a few early spots we left extra space around the insulation on accident. This was easily handled by cutting a thin piece, and putting more contact cement on to bind with old pieces.

We were originally worried that we would get condensation and mold behind the Armaflex, but so far that has not been a problem. We pulled off a poorly applied portion after a year, and noticed no mold or damage. In a perfect world spray foam insulation is a better option, but this has worked well enough for us. So far we’ve installed it in places that are not visible, and covering the V Berth. We’ve simply left it exposed for now, and while it will permanently deform if something rests against it, it’s actually able to bounce back and more durable than we would have expected. Long term however, we want headliners as it’s visually unappealing. To mitigate the visuals, we tried painting it with acrylic paint similar to the official Armaflex Paint, but even with multiple coats the pores were clearly visible.

Fighting Condensation

While a different topic, condensation and insulation are closely linked. Insulation stops condensation by raising the surface temperature of a surface, but that doesn’t mean there is any less humidity in the air. It will simply find somewhere else to condense that is colder. In order to stop this, you have to fight both temperature and humidity. Insulation deals with temperature, but to fight humidity it’s best to keep air moving so it can’t rest, and to try to find ways to bring the humidity down. The best way to do this is to either run a dehumidifier, or bring in cold air from outside. Even if the humidity is the same outside, if the temperature is much colder than it will also hold much less water. This makes the absolute humidity lower so that when the air is brought in, it brings the total humidity in the boat down.

There is an interesting article about taking advantage of this here, but we didn’t find the fan solution it suggested to work. If it’s raining, foggy, or too cold inside, insulation is bound to happen. Long term the best solution is a combination of insulation, and a heater that increases air circulation (like a diesel or wood stove).