I need to cover the "shelter group" in my 72 hours evacuation and shelter-in place kits.

I quickly browsed through that pdf tarp primer on equipped.org website and noticed that most designs use a 1:1 ratio (square) tarp.

The closest I found around here is World Famous 8' × 10' poly tarps for only 5 bucks at LeBaron store (I would use one to practice and another brand new, never unfolded would go in the inner sleeve of my Bundeswehr alpine rucksack [my BOB]).

So should I go with the cheap blue rip stop polyethylene type with limited UV resistance and flame retardancy or find a canvas cotton duck tarp?

What is the reason behind the 5:6 ratio (8' × 10' and 10' × 12') instead of square most poly tarps at hardware and camping stores come in?

Thanks
Frankie

Weigh them both, then decide. Canvas is heavy.

This summer, we started to use an unused nylon tent fly from an old 6 man tent as an expedient shelter. The fly is extremely lightweight and is treated with both waterproofing and a fire resistant spray which can be had at many hardware stores.

After 15 or so multi-day lightweight camping and hiking trips, it has held up well with no leaks. The fly folds up compactly and was easy to deploy when we had rain storms or for our nightly shelter. The only downside with not carrying a real tent is the mosquitoes, but that is why we carry bug dope.

Take a hard look at the Tundra Tarp from Cooke Custom Sewing at http://www.cookecustomsewing.com/tundratarp.htm .

These tarps are top quality and used & recommended by many Boundary Waters Canoe Area trippers. Favorite sizes/types include the 10'x10' and the 10'x12' of the 1.5 oz variety.

If you get it, please don't just stuff it in a bag to rot there. Use it and enjoy it.

I'd LOVE to get one of their Leans shown at http://www.cookecustomsewing.com/leans.htm , but the budget (and wife) won't allow it.

I use the MEC Scout silnylon tarp which is 2,1 meters by 2,9 meters (8' x 10', more or less). It's not cheap (64$ CAD) but I would never carry a cheap blue tarp in my backpack anyways (way too heavy and bulky).

The Scout (in it's silnylon version) is very light and easy to manipulate (it has a very soft, supple feel to it).

As for the rectangular/square thing, it's no biggie. I've used my tarp in several configurations (A-frame, lean-to). The secret here is to PRACTICE. I've rigged plenty of shelters using chairs and living room cabinet handles

Hi SARbound, I appreciate your feedback. However for an emergency 72 hour kit I would rather have a dozen of cheap tarps than a single expensive fancy one. If I started backpacking as a hobby then I would consider acquiring this kind of tarp.

Frankie

There are nylon tarps available that aren't as light as the SilNylon tarps. Check out the tarps at Campmor.

The lightweight tarps are "1.1 oz. silicone impregnated ripstop nylon. Very strong and extremely water resistant." I carry the small 6x8 in my get home bag (9.2 oz), it packs small. For comparison, the 10x12 weighs 19 oz.

Next up would be the Coated Nylon Tarps which are "1.9 oz. per square yard reinforced high count taffeta nylon. Very light and flexible. Waterproof urethane coating." I keep a 12x16 in my truck, it's a nice piece of gear to have in a pinch. 10x12 weighs 37 oz.

Last would be the Ripstop Woven Polyethylene Tarps. Definitely less spendy, but they're heavier. I've used them in the past, but prefer nylon. 10x12 weighs 4 lbs (64 oz).

If you don't intend to carry one on your back, the Polyethylene Tarps might work fine.

Frankie,
Find a store that sells beds and mattresses. Many of the warehouses use heavy guage sleeves to repackage mattresses. The queen and kingsize are obviously double those bedsizes. Use your charm and a few Loonies to buy one or two. A roll of duct tape to hem the edges and corners and you're set.

ALL synthetic tarps will eventually breakdown under sunlight and simple wear. It's a matter of frequency of use.

The Genuine British Army Basha makes for a good individual tarp,

http://uk.youtube.com/watch?v=EYXEyKYjOqE

http://www.surplusandoutdoors.com/ishop/877/shopscr1653.html

The Australian defence forces Hootchie is pretty good as well being slightly lighter but more expensive

http://www.raymears.com/Bushcraft_Product/81-Australian-Waterproof-Hootchie-Flysheet

Hilleberg also makes a nice tarp called the Tarp 5 XP

http://www.moontrail.com/hilleberg-tarp5.php

Did you think of the U.S. Military poncho/shelter? any Army Navy store will have them, and they don't cost an arm or a leg.