Insulating Shipping Container Home Walls, Floors, and Roofs.

First Name: EJ

Last Name: Mxxxx

Your Email Address:Undisclosed

Project Budget: not determined

Project Location: Nederland colorado

Project Description: retreat cabin

What would you like help with?

As I understand it, by the time I insulate the walls, floor and roof to r30, I would not be able to stand up in the space.  How does one insulate a container project?

Unless you are building on an insulated/heated slab on grade or in a moderately warm climate, the ground floors are the trickiest part of a container building to insulate.  For the walls and ceilings there are many options; batt (R 3.25 per inch ~ R30 would require 9-10"  ), foam panels(R 5 per inch ~ R30 would require 6"), and standard spray foam (R 6.75 per inch ~ R30 would require 4.5").  You certainly loose some interior ceiling height, but still ample room/clearance.

With the floor, there are fundamentally three options;

  1. Insulated/heated slab on grade (as mentioned above),
  2. Traditional crawl space (roughly 3') with batt insulation under container between the purins, or
  3. If you are trying to minimize step up to finish floor from grade, you can use closed-cell polyurethane spray foam on the underside of the container. This type of spray foam insulation has a very high R value (R 6 per inch) and durable. This yields R30 in 5", which fits within the 5.5" depth of the purins.  Takes some logistic planning or crane help to get under there to spray it on, but works.

More information on insulating your shipping container home available at the Insulation and R-Value Table links in the Reference section.