Beadboard for Hull Insulation?

[PatrickS]

I'm about to insulate my boat throughout and was going to use extruded foam (XEPS) but have a source of essentially free 1/2 inch beadboard (MEPS) that I'd prefer to use to save on expenses.

I've read, though, that the bonding agent in beadboard can absorb water over time and am wondering (a) how big a risk that really is in this particular application, and (b) whether that was a problem with earlier formulations but not with the current stuff.

I anyway intend to paint over the insulation with a water based latex in most areas, and am thinking that between the contact cement on the hull side and the paint on the other side, that may serve to sufficiently minimize any absorption that otherwise might occur.

Eh?

[osirissail]

If you are talking about the white foam insulation boards that when broken into pieces little white balls/beads fly everywhere - - DO NOT use that stuff.
It is porous and water, algae, and all sorts of mold works it way into the foam board and you will end up having to remove it all and sterilize the boat.
- - Only closed cell polyurethane - blue board or now pink board can be used for hull insulation. From a technical description of the proper insulation boards: "Polyurethane and polyisocyanurate are both closed-cell foams that contain a low-conductivity gas in the cells (usually one of the HCFC or CFC gases.) The high thermal resistance of the gas gives these foams an R-value of between R-7 and R-8 per inch."
- - The panels with the aluminum foil (shiny) are even better but bend less than the blue/pink boards.