Sheeting under plywood on Fish house frame

[1lessdog]

What is the sheeting called and where can I get it. I seen it on some fish houses. Its black looks to be 4 x 8 sheets and close to 1/8 thick.

 

I have a trailer/frame being built and would like to put it down first before the pink insulation and 3/4 plywood.

[rl_sd]

I believe that you are looking for HPDE.

 

https://www.menards.com/main/building-materials/panel-products/plastic-utility-panels/1-8-x-4-x-8-hdpe-panel/blkhdpe48x96x118/p-1561703293092.htm

 

 

So, just so I have this correct... you are going to insulate between the cross members and run HPDE under the frame and 3/4 plywood on top??

[1lessdog]

No my plan is to lay the HDPE on the top of the frame. Put 1 inch pink insulation on it then 5/8 or 3/4 sanded plywood on top.

 

Is it better to put the HDPE on the bottom of frame and insulation between the cross members. If I did that I would need to use 2 inch insulation.

[rl_sd]

What I have seen others do is run 3/4" marine plywood directly on the frame, top that with foam and then use 1/4" subfloor on top of that. You are going to want to make sure that you get the most rigid base on top of the frame.