Shelter R factors

[woodwose]

Ok, now I have a question..

Does anybody know or have information on what the R factors would be on materials found in nature that could be used to make a shelter. Sure, primitive emergency shelters need to be small enough to concentrate your own body heat but how thick would a person build a debree(?) hut at a given outside temperature to stay warm with no fire at the opening?

The only information that I have found on this is a short mention of it and that was to go look at the squirrels. I have looked at the squirrels in my back yard so much that they are beginning to look at me.

It is impractical to carry rolls of fiberglass insulation out there. Any suggestions or links? Thanks.

[RobertRogers]

Woodwose, this is indeed an important consideration. In general, insulation quality depends upon the amount of dead air space it traps.

For example, two feet of dry leaves will have more insulation than two feet of solid rock or two feet of wet leaves. There is no trapped air space in solid rock, so if you put your body against it you will get cold very quickly.

You also need to insulate against wind and water (rain), both of which rob your shelter of heat. It would be impractical to carry enough insulation for your shelter - you would be far better off carrying all the extra clothing you could and wear that.

Last winter I made a winter survival shelter (http://www.survivaltopics.com/survival/winter-survival-shelter-de-constructed/) in which you can survive the coldest weather even without proper clothing or sleeping bag. The key is to stay dry, have a minimum of space inside that your body needs to heat, and have a maximum amount of insulation all around the shelter. In this case I used branches and snow, both good insulators.

Some say eight inches minimum insulation but it all depends on how much you can gather in the time you have. Of course 50-ft is even better but realistically you would be hard pressed to do that. The point is, you do the best you can do with what you have.

[Beo]

If your out in the snow or just wanna try this the following tips are provided for constructing a snow cave. The "T" method of snow-cave construction is described below.
Select a site facing away from the sun with a slope of 45 degrees or greater.
Start by cutting a rectangle, approximately 5 1/2 feet high by 2 feet wide, into the snow bank. This will be the entrance to the snow cave (for illustrative purposes, the main stem of the "T"). The combination of cutting blocks with a harchet, knife or machette. Dig into the bank far enough so your head is now inside when standing up. At waist height (about 3 1/2 feet high), make the initial cuts for the left and right side bars (left and right arms) of the "T". Each side bar should be about 2 feet long and about 2 feet deep and about 2 feet high. The initial purpose of the side bars is to initialize the platform used for sleeping and to open up the construction area so that excess snow dug from the cave can be easily removed. Picture a "T". The main stem is about 5 1/2 feet high and 2 feet wide. Either side bar is about 2 feet high (with the top of the side bar flush with the top of the main stem of the "T") and 2 feet long. The resulting "T" is about 5 1/2 feet high and six feet across the top. The rest is time consuming, but not difficult work. Enlarge the sleeping platform by cutting back into the slope. To create the necessary head room above the sleeping platform, cut upward enlarging the ceiling. These chunks of snow will fall on the newly formed sleeping platform and are easily moved out of the snow cave. In this process, a sleeping platform with a domed ceiling is constructed providing ample headroom for sitting. Near the entrance, make a seat on one side of the passage way, which is used to cook and read during the evening. Save the blocks cut out to make the seat to seal the entrance.
When finished with the internal construction, use the saved snow blocks (along with others needed) to seal across both side bars of the "T’, leaving only the vertical entrance exposed. The top portion of the entrance can be sealed to give more protection from the elements. The resulting crawl space can be covered with a small nylon tarp or plugged with a pack. Place evergreen or pine needles, or leaves on the platform. You are now ready to enjoy your shelter and the evening in comfort.
Even though the process of building a snow cave takes at least 1 1/2 hours, the final comfort and pleasure make it worth the effort as inside is certainly warmer than the cold winter’s night.
Now this is a good sized snow cave but can be made you can shorten the size to your needs.
Beo,

[Beo]

Or try this way as a snow cave can mean the difference between life and death during a storm, but digging one requires not just know-how but the right conditions: deep snow, a steep slope, and snow of the right consistency for digging. Begin by digging an entrance large enough for a climber to crawl through. It should be about three feet deep and dug directly into the slope. The entrance should also be lower than the main chamber to prevent winds from blowing into the cave. Next, dig the main chamber in, upwards, and to the sides of the portal. Do not dig down. The outer walls should be no less than one foot thick. As the climber digs, he/she (owl girl, see I'm learning :D) pushes the snow to the doorway, where a partner helps shovel the snow outside the cave. Continue to dig until there is enough room for the number of people in the party to lie down and to sit or stand comfortably. The main chamber should be level and flat. After the main chamber has been dug, create a ventilation hole with a hatchet or knife. When all occupants are inside, blocks of snow can be placed in the doorway to stop wind from blowing inside.