100R

insulation

21.07.15
North Saanich BC, Canada

We have largely avoided winter these past 5 years, having instead chosen to follow summer around the Pacific. This was a good plan, we think. But we have since returned to Canada, a place not known for its tropical weather.

In the winter of 2020-2021, we woke up one morning with 2 feet of snow on deck. "Ah," we thought, "it snows here too." We cannot tell you why we thought there couldn't be snow here. We stayed in Victoria, the southernmost place in British Columbia, but apparently not south enough.

Armed with a new understanding of local weather, and two electric heaters, we kept Pino warm, but certain areas of the boat suffered because of condensation. While in new zealand we insulated the v-berth, badly. Shoddy, shoddy work. Our walls resembled a mountain face in Nuku Hiva after a big rain. We had used camping mats made of 1 cm EVA foam with a foil backing. We had glued it with a spray adhesive. It helped a little, but the glue was not applied correctly, and we had not cleaned the wall underneath it well enough either.

This year we are determined not to have a repeat of the winter of 2020-2021.

We installed a woodstove in the main saloon. Wood stoves give off good, dry heat which should help keep the boat warm when we are off-grid. We also made curtains for our windows. Pino's windows are very large, and a significant source of heat loss. Next on our list is insulation important, and accessible parts of the boat.

Insulating a boat while it still has walls, floors and ceilings is an impossible job. We are not aiming for perfection, because perfection involves tearing the boat to pieces, but we will do our best to deal with exposed surfaces. In all though, the very best way to avoid condensation is ventilation.

We tore the old insulation off, and found that some came away with little mess or effort—a bad sign that our first installation was indeed shoddy. We scraped off the glue, and cleaned the rest off with acetone. We instead re-used the sheets of EVA foam to insulate our lockers.

Then, we epoxied a series of wooden strips to create a scaffolding along the hull. We found this wood in the workshop of the local sailing club. People leave scrap wood from projects, good wood, and now it is ours. We plan to paint the wood with a thin layer of epoxy, so that mold can't reach our precious material. We had to make a lot of thickened epoxy to fill gaps between the wooden strips and the hull.

Our boat has a bulge in the center of the wall, running from bow to stern. Apparently, this is to reinforce the hull. Handy. We removed the trim that was there previously, and plan to re-use it after adding the new upholstery. The bulge would be useful, we can use it to 'frame' the insulation.

For this project we alternated between fancy, and so-so resin. One dried quickly, the other slowly, and its smell lingered in the cabin for days and days. West Systems resin is not cheap, but it is very good, and we regret trying the cheaper variety.

Next, came time to choose our insulation material. We chose Foamular, or XPS(extruded polystyrene). Foamular is pink, with a line drawing of the pink panther overtop—we wondered how they managed to get the rights to do that, ah well!

XPS is easy to find locally, this, its price, and high R-value per thickness is what inspired our choice. It has a R-value of 5 per 2.54 cm(inch), and it outperforms most other types of insulation, like Polyiso. Unlike Polyiso, XPS is less stiff and can follow curves better (depending on chosen thickness). The only thickness available to us was 2.54 cm (1 in), thicker than we wanted, but we think we can make it work. It might shrink the v-berth a bit, but we don't think this bothersome. Warmth is preferable to width(ha). We'll likely layer a thin material overtop, so the wall won't be much thicker than this.

What else is there?

What about Reflectix? Reflectix is a reflective insulation which functions best in specific situations. If you do not provide air space, Reflectix has less insulating value. It is useful to insulate areas that are impractical to insulate using other means, say due to lack of space, like around pipes or restricted areas. The product reflects heat back, rather than mass insulation such as the material examples stated above. On a boat, it might be useful to insulate a mast, or outside windows to reflect heat. **Don't place reflectix inside windows, as it can reflect heat back too well and can warp the windows.

The work

We measured each section we would have to cover with the foam boards, marked them up and cut shallow lines across its length and snapped off the pieces right off. We tried cutting them with a bench saw, for fun, but it is too fast, it makes a mess and if you're too slow it melts the foam.

Next step, is to affix the cut pieces to the wall. We bought some polyurethane adhesive (formula for foam boards), applied it to the back of the board and pressed it on firmly. We used mechanical support to press the board onto the wall while drying. We only have so many pieces of wood for support, so we are applying 3 at a time.

It took a few days to get all of the boards on.

Next step is to add foam spray to seal cracks between the scaffolding and foam boards. It is quite easy to use, but it makes a mess. At least, it is easy to trim. We posted the above picture on Twitter, and people made fun of our Chernobyl-esque accoutrement. It ain't nuclear waste, but it isn't good to breathe or get on your skin, and hey, we like not having asthma.

Our friends Rik and Kay drove us to Home Depot to pick up some carpeting. We picked up two 1.82 m(6 ft) by 2.43 m(7 ft) rolls. We plan to use that as finish for the walls. We thought of using vinyl flooring, but carpet is cheaper, and may provide more insulation. The carpet is for outdoor/indoor uses, are 100% polyester, and won't rot. Also, it's easy to cut and isn't too heavy. The vinyl flooring is nice but would add too much weight.

We trimmed the excess spray foam, and painted over with an acrylic latex paint. The foam isn't as waterproof when cut, so sealing it with something is necessary. Leaving the foam uncut would have been better, but then we would have very, very lumpy walls.

We cut the carpet to match the shape of the wall, and laid on some outdoor carpet adhesive (Home Bond). We tooled adhesive on the whole surface, and pressed on the carpet.

We also added the trim back on top, fixed on the fibreglass bulge lining the space. It looks amazing! We're so happy! The wall wasn't perfectly smooth prior to applying the carpet, but it barely shows.

The interlocking foam pads were there prior to the start of this project.

In the end, we didn't really use the scaffolding we'd built. At the time, we thought we'd use it to mount vinyl walls, but then we chose to lay on carpet. In any case, the scaffolding reinforces the wall, and if ever we decide to add shelving then we have something to use as backing.