Insulated Ramp Door Source for build?

[sparetime]

For all the shack builders out there, where can I get an insulated ramp door for an upcoming build or do you make them yourself?  I'm planning a fairly simple 6.5x12 shack.  Haven't fully committed to the ramp - plenty of positive and negative aspects of that. 

[rl_sd]

You could call Ice Castle in Montevideo MN.... sometimes they have some "scratch and dent" stuff. Otherwise you could insulate it yourself..

http://stealthcargotrailer.blogspot.com/2010/07/insulating-rear-door.html

 

PROS: Haul wheeler/snowmobile easily, use as cargo trailer in the summer

CONS: Added weight, air drafts, added cost, less configuration options for bunks

I just got done building a 6.5 x 14 and it crossed my mind to put a ramp door in but quickly decided against it due to the type of fishing that I do and the purpose of the house.

[sparetime]

If I were to look for an uninsulated ramp door with the intent to insulate it myself, where would I find such a thing?