Tyvek - the perfect groundcloth

Tyvek, known in the building trades as house wrap, serves as a vapor barrier in the walls of buildings. Made from high-density polyethylene fibers, it’s ultralight, tear proof, very puncture resistant, windproof and waterproof. With these qualities, it’s should be no surprise that the stuff also has applications in the outdoor world. (Ever seen those bicycling jackets with the wild graphics and paper-like feel? That’s Tyvek.) It also functions as a perfect ground cloth or footprint for your tent. (It’s not good tarp material, as it has a very loud rustling sound in any sort of wind.)

The problem used to be where to get the stuff. Midnight raids on construction sites are taboo, and most building supply stores only sell huge rolls for over $100
Well, there is a way. Andrew Mytys, courtesy of his web site, sells Tyvek in perfect backpack sizes. You can buy it in widths of either 3 or 6 feet by whatever length you specify. The minimum length sold is 8 feet.

Extra tip: Copy a backgammon and checker board onto the Tyvek with a permanent pen, collect a few rocks, and play board games for hours of entertainment in your storm bound tent.

Where to buy Tyvek:  http://www.geocities.com/amytys/Tyvek.htm
In Portland you can get Tyvek by the foot from outdoor retailer Next Aventure.