the present invention incorporates fiberglass insulation which is contained between two layers , or outer skins , of woven polyethylene . this woven polyethylene may contain nylon reinforcement impregnated therein . the material of the present invention may be configured so as to be easily applied over devices for heating liquids or containers or vessels holding liquids , such as hot water heaters , and may further be used as a wrap or cover for insulting pipes and similar liquid conveyance means . the most common application for the material of the present invention may be hot water heaters . fig1 shows the material of the present invention configures so as to be used as a cover 2 for a hot water heater 4 . the cover 2 is formed so as to be able to wrap around the water heater 4 , being configureed so as to be of the proper height and length to be tightly wrapped around the hot water heater 4 . the cover 2 may be connected or closed by various means , including a zipper or hook and loop material 6 . this material can be configured so as to wrap other containers or to be placed as a wrap over pipes . the particular configuration will depend on the shape and design of the device to be covered , and may be accordingly constructed by commonly known means . fig2 shows a cross - section of the polyethylene 8 and fiberglass 10 material . a center core of fiberglass 10 is used , and an outer skin of polyethylene 8 contains the fiberglass . the fiberglass is packed into the outer polyethylene skins which have been sewn together about their perimeters . woven polyethylene is selected due to its superior tear and abrasion resistant qualities , its resistance to fire , and due to the fact that it retains its shape when formed as a cover . while fiberglass strands have long been used as an insualtion material , such fiberglass has a tendency to lose its shape , to tear easily , and to absorb water and foreign materials which cause it to lose its effectiveness . accordingly , fiberglass insulation has been placed between layers or sheets of paper , plastic or foil so as to shield the fiberglass from formed materials and to aid it in holding its shape . however , the inventor has discovered that woven polyethylene is vastly superior to plastic or other materials in producing a material and device which will hold its shape while being resistent to wear , tear , water , abrasion and foreign substances . however , an unexpected result has occurred with regard to insulation properties . while a typical hot water cover using 4 &# 34 ; thick fiberglass covered by paper or plastic will have an insulative property of r8 , when the same amount of fiberglass is used and is covered by woven polyethylene in the manner taught hereby , the resulting material will have an r value of 10 . energy loss from heat transfer is thereby radically reduced by use of the material which is the subject of this invention . to construct a water heater cover as is shown in fig1 a first layer of woven polyethylene is cut from a larger piece so as to be of a proper height for the water heater to be covered and to surround the circumference of the water heater , while fitting tightly around the water heater . a second layer of woven polyethylene of the same size is cut in like fashion from a larger portion of woven polyethylene . the two layers are then sewn together about the perimeters of the sheets . fiberglass insulative material is then stuffed in between the two sheets of woven polyethylene . the insulative material may be stuffed either through an opening which is left along one edge of the perimeter of the sheets , or by splitting one of the two sheets so as to form an opening . if one of the sheets is split , the split may be closed , such as by the use of pressure sensitive tape , with the split turned to the inside of the cover when installed . sufficient fiberglass insulative material should be placed between the polyethylene sheets to achieve a preferred desired thickness of about 4 &# 34 ; for a water heater application . the insultive material should be uniform in thickness . a rope or line is pulled through the top edge of the cover , and a zipper or hook and loop ( velcro ) or other fastening means is attached to the edge of the polyethylene material where the edges are to be joined 6 . the cover is then wrapped around the water heater and joined by means of the hook and loop material , zipper or other fastening means . the rope is then pulled tightly around the top 12 , and each end of the rope is tied and tucked between the cover and the hot water heater . it has been found that , due to the configuration of the tank within the water heater and the insulation which is included within most water heaters , that an insulative top for a hot water heater is not of great benefit . however , a top could be fashioned as taught herein .