A method of pulling a sheet of flexible material includes forming a row of a plurality of lengthwise slits in a sheet of material; providing at least one pull device; and providing at least one cable winch. A tubular pull rod is inserted through the plurality of slits. A pull device preferably includes a first pull strap, a second pull strap, a spreader bar and a strap ring. First and second pull devices are positioned near opposing sides of the sheet of material. First and second winches are secured to the floor on one sidewall of the building. The sheet of material is laid on the floor at an opposing sidewall of the building. Cables from the first and second winches are pulled over struts in the building and secured to the first and second pull devices. The sheet of flexible material is pulled to the one sidewall.