Weldy Mini Welder Roof 2 Wedge Welder. Lightweight and easy to operate. Suitable for all pitched roofs, the miniwelder roof2 can be used for all PVC and TPO sub-roof membranes up to 1 mm. As the welding wedge technology manages without air having to be blasted, the sub-roof membrane does not flap about during the welding process. Don’t waste your money on toxic solvent welding agents.