Abstract: A fastener having a head portion, a shaft portion, and a hook portion which secures the fastener within a substrate. The hook portion may have a plurality of serrations on a surface thereof for gripping a substrate. The hook may be of a material having a memory such that, when the hook is compressed during the insertion of the fastener in a hole in a substrate, the hook will expand against the walls of the hole in a desire to return to its original shape. Such a fastener may be easily inserted into the hole, but considerable force is required to remove the fastener from the hole after insertion. The fastener thus can be inserted easily through soft materials overlying a hard substrate without damaging them while providing an effective anchoring force within the substrate in effectively fastening materials to a substrate.

Abstract: A device for welding portions of two overlapping roof membranes wherein a fastening means has been fastened to the lower of the two membranes and wherein there are portions of both overlapping membranes on both sides of the fastening means. The device includes a welding means which can apply welds to the membranes on both sides of the fastening means simultaneously. The welding means includes a nozzle having two outlets, with each outlet applying a heat sealing weld on one side of the fastening means. The device also includes a pair of weighted stitcher wheel assemblies which help to eliminate air pockets for underneath the roof membranes and to maintain the proper alignment of the overlapping membranes. The invention also includes a welding process using the above-mentioned device.

Abstract: A stress plate and method for securing a membrane to a roof deck wherein the plate includes gripping prongs which grip the membrane, preferably without piercing the membrane, wherein a stress plate surface having the gripping prongs is placed in contact with a top surface of a roof membrane to clamp the membrane to a roof structure.