Jam-Ex®

JAM-EX® is a semi-rigid, 60 mils thick, an extruded thermoplastic product used to extend the jambs, heads, and sills of windows, storefronts, curtainwalls, and doors in exterior walls of buildings that include air and vapor barrier systems. It was originally developed for precast concrete panel veneers but can be used to replace wood blocking and metal flashings in masonry veneers in cavity wall construction. When using this product, the windows, storefronts curtainwalls, and doors will have to be fastened to the backup wall construction with anchors, plates, or clips.

Wood blocking will usually warp as it loses moisture. If windows, storefronts, and curtainwalls are fastened to the blocking, they can be distorted from their original shape by the warping. This can result in the waterproofing seals at the joints in the frames of these assemblies being compromised. Fastening these assemblies to the backup wall with anchors, plates or clips eliminates the possibility of this occurring.

Metal conducts heat. Heat seeks cold. The use of metal flashings can result in the loss of heat within them to the point where their temperature is below the dew point temperature of the air surrounding them. When this occurs, condensation will form on the surface of the metal flashing and could collect in locations within the exterior wall where it can cause mold, corrosion or degradation of materials.

JAM-EX® is fabricated from a custom blend of resin-modified, UV-resistant thermoplastic. It will resist job site exposure to chemicals and abuse. This same formulation will last the intended life of your building.