Bamboo Shield- 50 foot long x 36 inch x 100 mil bamboo root barrier/water barrier 100 mil material thickness that provides 200 pound-force puncture resistance. Industry Leading Thickness Made from High Density Polyethylene (HDPE). Controls growth of bamboo by limiting rhizome (root) expansion Superior to metals because it will not rust and easier to install Protective side is chrome rolled to provide a better rhizome deflection surface. Shiny side of the barrier goes towards the bamboo. Slightly angle barrier (5-10) where the bottom is closer to the bamboo. A minimum of 2 should be left exposed above the soil level. Material tends to remain coiled after shipping. Expanding it out in the sun for a few hours can make installation easier. Locate and confirm the location of all underground utility lines and structures prior to digging and use caution.