Use duct tape or something similar to tape it up. I'm using something called "nashua tape" which has a mirror finish, an adhesive backing and is easier to tear than duct tape (I got it from Home Depot). I have found that both electrical tape and duct tape lose their stickiness eventually and the UTH sags. Another thing to help it stay up and to help with heat retention is to tape a piece of aluminum foil on the outside of the UTH (i.e. tank bottom, UTH, aluminum foil).