I was recently asked about toxic finishes in shipping containers. I am no expert on such matters, but I read up on the subject a little and found a lot of opinions with no sources, some information about industrial paint issues, and advice on choosing new paint.
Generally speaking, I think building and renovation work has to stick to its priorities, both in terms of space use and building performance. It’s easy to fall into ‘while we’re at it..’ in any project: we all have a drive to wipe the slate clean and start fresh, to layer it all over with a fresh coast of wallpaper. But wallpaper, and laminate, and glue, and mortar, and paint all become a sticky un-recyclable mess of extra finishes with extra chemical elements and extra stops on the manufacturing chain. Now I know that this building is made from shipping containers made in China and shipped halfway across the world, the irony is not lost on me, but these containers came to Nova Scotia filled up with little plastic trinkets all on their own. We simply purchased them once their initial shipping function was completed.
In thinking about finishing the shipping containers for the house in Mira, I had been thinking about necessary finishes (insulation, gyprock over the insulation), about keeping something of the essence of the material itself (industrial steel), and about eliminating unnecessary layers in the construction (finishing on one side only). Toxicity wasn’t forefront in my mind. But the question is a very good one. So after a bit of research and reflection, here is my take on existing finishes and liveability:
Our containers are painted with marine paint from International Marine Coatings. This company phased out lead and a bunch of other nasty ingredients a few years ago. The paint we have is no all natural milk paint, but it meets the new Canadian standards for VOC emissions in metal paints. And since our containers are new, the paint is well-adhered and in excellent condition. It seems to me that grinding it all off and using more paint isn’t the most low-impact course of action. So we’re leaving the paint as is (with touch-ups as needed, and proper masks and ventilation for the cutting and welding work).
The floors are hardwood plywood – maybe mahogany. No FSC certifications that I can see. And the wood is treated with Radaleum FHP-60 – basically it’s cockroach powder impregnated in the wood. As this wood is sound and already in place, our plan is to seal it and use it as a finished floor. We will either use an epoxy or a clearcoat like Safecoat Hard Seal, after a little washing as recommended by another container house builder who has an excellent post on this subject: tin can cabin . This seems to me to be the most low-impact solution, rather than demolishing and installing brand new plywood.
Hopefully these strategies get us closer to our common goal – to make safe and comfortable space for people while minimizing the impact on the land.