You may also be interested in this post on double glazing r and u values and log cabin thermal.
How to insulate a cabin floor.
Cover the walls with insulation from the sill plate to the plastic covered dirt floor.
Approximately 70 of heat escapes through the floor and roof it is therefore essential to insulate them well.
When you re using fiberglass batting insulation material run it about 6 inches or so onto the crawl space floor.
According to the 2012 irc the minimum r value for floor assemblies is r 13 in zones 1 and 2 r 19 in zones 3 and 4 r 30 in zones 5 and 6 and r 38 in zones 7 and 9.
When we built the addition to the cabin last year we skipped a few steps.
These are some of the basic options you will find to use as floor insulation for your log cabin.
If you were one of my customers and you were buying a lovely new log cabin from me especially one of our thicker wall log cabins such as 50mm upwards i would be strongly urging you to insulate at the least the floor of your new log cabin.
It will provide additional insulating value for not too much more than what would be invested in the r30 insulation.
Place the batts against the underside of the floor then cover with the hardware cloth securing it to the joists with a staple gun.
A closer look at the primary equipment.
The air space above the 9 1 2 inch insulation in the 12 inch joist cavity will help provide a warm floor inside the cabin.
The two areas i would absolutely recommend insulating are your floor and roof.
When we built the addition to the cabin last year we skipped a few steps.
Insulating the floor log cabin flooring is made up of packs of tongue and groove boarding nailed to pressure treated bearers.
I would also try to nudge you to insulate the roof as well.
Directly beneath the flooring and between the joists fit foil backed insulation boards for example 25mm or 50mm celotex a compressed foam material between silver foil.
This size of metal screen should be small enough to keep out nuisance animals such as mice.
The sill plate is the first piece of framing lumber and it runs on top of the crawl space wall.
Alternatively you could fill the cavity completely using r 38 faced batt insulation.
If you want to insulate a floor assembly by leaving the joist bays empty and installing rigid foam on the underside of the joists here are a few things to keep in mind.
Cover your insulation with 5 mm 1 4 hardware cloth.