squatch wrote:Once the whole outside was skinned and painted then add a piece of 2" or 2.5" aluminum angle all the way around the outside edge.
I see a problem with anything on the outside as water coming down the outside (Rain) would then have a route between the aluminium and the foam to the floor where it would sit. The glues we use dont seem to mind a lot of water but just like plywood they dont want to be left damp as it just penetrates and will rot. Its far better to let it run off.
Water that runs down and that seeps up, will dry but if there is somewhere it can puddle it will soak in and stay wet.
Far better to just have the cloth / TB2 over this area on the outside, folding it under so there is no where for water to get in at all. If you feel it needs more strength use another strip of cloth and TB2 as GPW does. You will be amazed how strong it gets.
Your idea of a "1"x3" or 1"x4" on edge all the way around on top of the plywood" would work great idea as it would act as a large key as well as give more area for the foam / wood glue to join. It would certainly stop all shear in the wall to floor joint.
From everything I can see and understand about this Foam stuff, it has very little strength when you stress it in a small area, so you have to spread the load over larger areas. Foam gets its extra strength from having a covering stuck to it which makes the stress spread over a large area.
I have now found another supplier for foam covered panels in the UK and they supply the product to RV manufactures.
For interest
http://www.coldsaverpanels.co.uk/panel-systems.htm
Basically its the foam covering that give it strength, this can be almost anything and certainly cloth / TB2 has been proven to work, people just need to be convinced