The beauty of foam is you can determine the density just by weighing it ... The 1# per cu.ft. is standard pretty much , the 2# per cu.ft. is much more dense and solid ... We’ve even seen heavier versions of beaded foam , even more solid , not that it’s necessary ... the 1# cu.ft. is what we used on the FoamStream , with no problems , great strength ,over a wooden skeleton , and using heavy canvas (18 oz.) for the outer skin .. Use what you can get , and use it wisely ... We’re building simple camper trailers , that’s all ..
![Wink ;)](./images/smilies/econ_wink.gif)
And on the other hand if the trailer wasn’t to be used except for Good weather camping (like CA, where it never rains and the temperatures are always moderate
![Cool 8)](./images/smilies/econ_kewl.gif)
) , then you could eliminate the foam entirely and do a Canvas over wooden rib and stringer frame (vintage Aircraft style) trailer... That would be Cool and very light ...
![Thinking :thinking:](./images/smilies/econ_thinking.gif)