1. Materials a. Graphite Polystyrene Insulation i. Shall have a minimum R-value of 5.0 at 1 inch when tested in accordance with ASTM C518 ii. Basis of design material is BASF Neopor F5000. Equal substitutions will be considered. b. Metal Flashing i. Shall be aluminum, preformed or field-formed, with an upper vertical leg (portion that underlaps siding and weather barrier) of at least 1.5” (for vinyl siding integration) or ½” (for window sill integration), a horizontal leg (portion that extends over top edge of insulation) of at least 3-1/4” with a positive slope, and drip edge/kicker projecting away from the insulation. ii. Equal substitutions will be considered as long as water management over top of insulation is maintained. c. Finishes i. May be one of the following finishes, owners choice. 1. Stucco finish with base coat and reinforcing mesh 2. Alternative options may be considered d. Accessories i. Foam Board Adhesive (ex. Loctite PL 300) or mechanical fasteners with washers ii. 100% silicone sealant and closed cell backer rod iii. Fasteners/Adhesives (as recommended by flashing and finish manufacturer) iv. 3M 8067 All-Weather Tape (for counterflashing metal flashing) 2. Installation a. Existing foundation surface and surrounding finishes shall be properly prepared and/or removed as necessary to accept insulation, flashing, and finishes. Finish materials removed shall be salvaged to the extent possible in instances where salvaging materials is more cost-effective than replacement. b. From the exterior excavate into the soil/gravel around the foundation and expose 12 to 18” of the below-grade foundation wall. Wash off the soil and allow the walls to dry completely. c. Remove vinyl siding and window trim to the extent necessary to install aluminum flashing. i. Vertical leg of aluminum flashing should underlap existing vinyl siding as well as any weather barrier/building wrap, if present. If no weather barrier/building wrap is present and access allows, counterflash the leading edge of the metal flashing with a weather-barrier self-adhesive tape. ii. The horizontal leg of the siding should sit just below the bottom edge of siding, with 1/8-1/4” gap. Bend the horizontal leg downward slightly, if necessary to create a positive slope. Reinstall siding fasteners. iii. Overlap butt ends of flashing 3” minimum and bed in sealant. iv. Install metal window sill flashing that provides water management below the finish sill to protect water from draining behind the new insulation. Sill flashing should be fastened back to the CMU, counterflashed with allweather tape. v. Extend metal flashing 2” past the jambs to catch water that may drain between jamb extensions and insulation. d. Adhere 3” thickness of rigid graphite polystyrene (GPS) foam board to the foundation with foam board adhesive per manufacturer’s instructions. Mechanical fastening with washers is also an acceptable method. Set the insulation from the bottom of the trench up to the top of the foundation. If insulation is to be installed in 2 layers, stagger layers 6” in both directions. Insulation should terminate close to the underside of the flashing but maintain a slight gap (approx. ¼”) so that it does not press against the flashing and create a negative slope. e. Build out head, jamb, and sill extension around each window unit with PVC trim to ensure concealment of insulation edges and a flush fit with new finish plane. f. Cover the above grade GPS insulation with stucco and reinforced base coat or fiberglass reinforced plastic finish, following AWCI best practices (for stucco and reinforcing mesh) and manufacturer’s installation instructions. g. Provide a backer rod and caulk seal between jamb and head window extensions and the rigid insulation and top of foundation flashing, respectively. Follow sealant manufacturers instructions to create a proper width-depth ratio and tooled joint. Leave joint between sill extension and sill flashing open to promote drainage. h. Backfill the trenches in the soil and replace gravel drip bed.
