2022-09-26-minutes-public-works-study-session

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N'YS , 1.02 - AIR LEAKAGE CAUSES The air leakage throughout the building at all three primary leak locations is occurring due to improper application and sealing of the air/vapor barrier scrim to the concrete or metal structure. The air/air/ vapor barrier system is also not properly sealed to penetrations through the exterior walls such as ducts/louvers, electrical penetrations, and plumbing penetrations. The lack of proper termination of the air/vapor barrier material to the concrete slab or the metal framing components is allowing bulk air to pass through the structure. This is especially problematic during the winter when the warm moist air meets the cold air from outside and condenses leaving liquid water to form and cause deterioration of the structure. The images shown below outline examples of locations where the white air/vapor barrier membrane is not attached/sealed to the concrete slabs, metal framing, roof to walls, and penetrations. It could not be determined, without destructive testing, if the insulation is applied on the exterior side of the metal columns; if the insulation is not continuous around the metal columns the condensation risk is 'highly elevated'. If the insulation and air/vapor barrier scrim are not properly surrounding the metal structure, condensation will occur rapidly and cause accelerated deterioration of the building. Recommendations: All repairs recommended below should be performed in accordance with the manufacturer's installation instructions and with materials by the original manufacturer wherever possible. • Remove metal panels at base of wall as need to properly seal the air/vapor barrier to the concrete (wainscot horizontal panels). While the panels are off, inspect insulation to ensure the proper thickness is present and it is continuous. Note: in the shop area, the scrim can be accessed from the interior to seal to the concrete. • Remove metal panels as needed from all vertical structural columns in the administration area to allow access to seal the air/vapor barrier and add insulation as needed. • At the shop area, the air/vapor barrier scrim is visible from the interior and can likely be sealed/repaired without panel removal. • At the roof to wall connections, seal all air/vapor barrier materials to eliminate all voids and holes. • In attic area, Install new sheets of airtvapor barrier to replace `taped' sections. Seal all seams and transitions. Note: this issue was listed in the LNS Engineering report; however, was not properly repaired. • In all locations that are opened for repair, inspect the insulation to ensure that no voids are present. • In all locations that are opened for repair, inspect air/vapor barrier scrim for holes or damage and seal per manufacturer's installation instructions. • Once all repairs are complete re -install the metal panels. Panels are to be re -sealed at seams with manufacturer required sealant and new gasketed screws. Kittitas County - Maintenance Building Page 9 of 19