Sheets may ntain rough edges or smooth skin. Polyethylene Thickness. Sheets thicker than 1/2" are made from 1/2" sheets laminated together. 2" Polyethylene may range in thickness from 2" to 2-1/4". HDPEpping 9LB Polyethylene. 9LB polyethylene sheets will be cut down from 19" x 108" to a 2-pack of 19" x 54" for HDPEpping purposes. Reviews.