Cavity wall through-wall flashing support system and method

A through-wall flashing support system for supporting a through-wall flashing membrane installed in a cavity wall comprising an inner wall having a lateral extent and an outer wall having substantially the same lateral extent, the inner and outer walls defining a cavity therebetween, the flashing support system comprising:

• a plurality of thermoplastic flashing support parts, each thermoplastic flashing support part comprising:
• a flange having a lateral extent and having a lower portion, the flange being configured to abut and be attached to the inner wall;
• and
• a base integrally formed with the flange and extending laterally along the lateral extent of the flange, and extending with a downward slope from the lower portion of the flange, the base having an outer portion, wherein the base is configured so that when the thermoplastic flashing support part is installed the outer portion of the base penetrates the outer wall and the outer wall supports the base;
• a plurality of thermoplastic flashing H-channel spline parts, each of the plurality of thermoplastic flashing H-channel spline parts configured to connect the bases of two adjacent thermoplastic flashing support parts, wherein each spline has a front and a rear, and has a flat upper surface and a flat lower surface and the distance between the upper and lower surfaces increases from the front to the rear;
• a through-wall flexible flashing membrane having a lateral extent and having rear and front edges, the rear edge of the membrane being adhered to the flanges of the thermoplastic flashing support parts, the through-wall flashing membrane configured to extend across the cavity and covering the bases of the thermoplastic flashing support parts, wherein when the thermoplastic flashing support part is installed a portion of the through-wall flashing membrane comprising the front edge of the through-wall flashing membrane extends through the outer wall,
• wherein a plurality of weep holes extend through the outer wall, the weep holes being located immediately above the front edge of the through-wall flashing membrane when the membrane is installed, thereby enabling water to flow along the portion of the through-wall flashing membrane covering the bases of the thermoplastic flashing support parts and through the weep holes.