Hi, I own a floating home build sometime in the 20's. It was probably originally built with stolen lumber as a budget alternative to a landed house. Needless to say insulation is lacking. We've added what insulation we can to most of the walls, sealed all known air leaks (there were lots of places where you could see water through the floor, wall, etc).

Now I'm working on the living room floor. The floor seems to be 5/4 inch t&g. I'm planning on adding electric radiant heat mats, and engineered bamboo over that. To maximize the heat, I'd like to insulate the floor. The issue is that I do not have much access to under the floor so I need an over the sub-floor, under the heating mats solution. I'm considering foil products (like Prodex), but am not convinced that they will help enough. Any suggestions?

For those doubting the under floor access: The house is built on a raft of old growth logs (~2-4 ft in diameter), on top of them are stringers that function as the foundation (~14"x14" creosoted), the floor joists run across the stringers. So to access the floor I would need to scoot across the 14" gap on top of the logs (think rusty spikes, algae, moss, etc. plus 1-4' gaps open to the water). The only way I can think to do this would be to go in through the top and I am unwilling to rip up the floor,


Thanks, Tony (no longer onHiatus), Seattle, WA