Homeowners in Boston, Va have a farm and wanted to insulate the walls in their barn. One of our evaluators, Pedro, determined that closed cell spray foam would do the best job at insulating this space. Closed cell spray foam adheres to all surfaces, expands in place, and air cannot pass through it. It has an R value of 6.3 per inch and with it's ability to stop air flow, it is superior insulation. One inch of closed cell foam sprayed in place is worth many inches of other insulation materials. This is why spray foam is used in most "zero energy" homes.