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HomeMy WebLinkAboutFile Documents.701 Gibson Ave.0086-2021-BRES (5) analysis ■ support ■ sophistication 911 Marfell Street ▫Erie, Colorado ▫ 80516 (303) 665-2703 Phone ▫ (303) 665-2705 Fax August 22, 2021 Leila Schwyhart Project Manager Bldg Seed Architects 417 Main Street, Suite B Carbondale, Colorado 81623 Information for Iris Project No. F20039.00 – Assessment of Exposed Cladding Issues: Project: Evaluation of Building Envelope and Pertinent Exterior Elements Description of Project: Bauhaus on Gibson 701 Gibson Avenue Aspen, Colorado 81611 Dear Ms. Schwyhart: Per your request, Iris Technologies, LLC conducted an inspection of the exposed exterior building assemblies at the above-noted location and assessed the general condition, configuration and performance of the existing hard-coat stucco cladding system. Descriptions of our observations and analyses of the home’s exterior cladding system, and recommendations for further exploration of latent conditions, are presented below. PERTINENT OBSERVATIONS AND PROJECT INFORMATION Based on our initial assessment of the subject property in January 2021, and prior to the initiation of renovation efforts, Iris Technologies noted that several areas of the home’s exterior stucco cladding system exhibited evidence consistent with water intrusions behind the cladding and possible degradation of the walls’ underlying substrate. Following the selected removal of portions of the exterior stucco associated with the noted anomalies, Iris Technologies examined the exposed areas and evaluated the composition of the hard coat stucco system; based on these observations, the following issues were identified: 1. The removal of stucco from the railing assemblies at the outer perimeters of the main-level patios revealed extensive rot and deterioration of the underlying plywood sheathing and supporting wood framing. The water-related distress and structural decay extended down below the patio framing and has impacted the backside, or outside face, of the railing assemblies. Where exposed, the deterioration of the exterior sheathing behind the stucco extended past the level of the patio and has impacted the home’s lower-level exterior walls. 1.1. The exposure of the exterior wall assemblies in the vicinity of the support brackets serving the glass panels of the patio railing system also confirmed the suspected water Bauhaus on Gibson – Assessment of Exposed Building Assemblies August 22, 2021 Page 2 of 3 intrusion of water at the improperly-sealed brackets. The lack of proper sealant joints at the other similar intersections between the stucco cladding and any dissimilar materials suggests that other, comparable latent water-related damages likely exist at other areas of the home. 2. The intrusive exploration of the stucco assemblies at the subject home revealed that the cladding system is comprised of hard-coat base and finish layers applied over varying thicknesses of rigid expanded polystyrene insulation, and these materials are applied over two layers of asphalt building paper. The direct application of a hard coat stucco system over rigid foam insulation is not supported by most stucco manufacturers, and such an installation technique leads to excessive cracking of the stucco and the resulting intrusion of moisture at the uncontrolled fractures. The placement of the closed-cell, non-hygroscopic rigid insulation between the outer hard coat stucco and the asphalt building paper (i.e., the drainage plane) also prevents effective movement and drainage of moisture from behind the stucco and can promote latent deterioration of the substrate. 2.1. Our evaluation of the exposed sections of the home’s exterior walls also revealed inconsistencies in the horizontal and vertical overlaps of the asphalt building paper behind the stucco. 3. Discoloration of the plywood wall sheathing exposed at and near windows and doors suggests that water is entering and/or becoming trapped at the perimeters of the fenestrations. A close examination of the stucco cladding revealed a lack of proper sealant joints at the jambs and sills of the windows and doors as well as the absence of industry- standard flashing at the heads of the fenestrations, and this lack of proper installation of the stucco cladding has likely generated some degree of latent water-related distress at most or all of the home’s windows and doors. The numerous cracks, blisters and surface degradation of the stucco cladding at the perimeters of several windows are further indicative of prolonged water intrusions at, and the retention of water behind, the improperly terminated stucco. 4. Examination of the exposed areas adjacent to the concrete topping slab of the upper-level patio revealed improper termination of the stucco and it water-resistive barrier at the base of the home’s upper level walls; the noted improper termination of the stucco assembly at the hard-surfaced patio appears to allow, or direct, surface water past the concrete topping slab and into the structure. 5. The coordination and configuration of the stucco cladding at the base and top of the spiral stair case chase extending between the South Patio and the Upper Patio is allowing water to become trapped behind the hard coat cladding; the further removal of the cementitious cladding at the stair chase will likely reveal extensive latent rot and deterioration at both the top and bottom of the circular chase. 6. At several locations around the home, the stucco cladding is improperly terminated at or below the abutting finished grade; based on the observed distress stemming from similarly- Bauhaus on Gibson – Assessment of Exposed Building Assemblies August 22, 2021 Page 3 of 3 configured stucco assemblies at the main-level patios, and the likelihood of water wicking up behind and/or becoming trapped within the improperly-terminated stucco, some degree of deterioration of the exterior plywood sheathing likely exists at these areas. 7. Cracking and blistering of the stucco noted at the base of several larger windows sills, beneath the patio surfaces, and at the bases of rake walls suggests the presence of additional latent water damages, including long-term degradation of the underlying plywood substrate and the potential for accompanying biological contamination. SUMMARY AND RECOMMENDATIONS FOR FURTHER EXPLORATION The inspection of the exposed exterior wall assemblies at the subject home revealed moderate to substantial latent water-related damages, including rotted and deteriorated plywood sheathing, compromised wood framing members and blistering of the hard coat stucco at and adjacent to several windows and doors. The intrusive examinations of the exterior wall assemblies also revealed that the composition of the stucco assemblies around the home are not consistent with industry standards for hard-coat cementitious systems, with the presence of rigid expanded polystyrene insulation beneath the stucco finish reducing the ability for moisture to reach the drainage plane and likely contributing to the extensive cracking noted across the home. Based on the exposed distress and presence of other similar anomalies across the still-present stucco, additional intrusive examination of the stucco system is essential; further, due to the composition of the exterior cladding, a significantly larger scope of repair must be considered for the home’s stucco in order to achieve a warrantable installation, including the possibility of a comprehensive removal and replacement of the non-conforming cladding. All comments made in this document are based on the conditions observed at the time of the site investigations and information available at the development of this report. Should additional information be presented or discovered, Iris Technologies, LLC can amend, modify and/or supplement the opinions presented in this document. If desired, Iris Technologies can, upon request, provide additional information on, or oversight of, the additionally-required intrusive exploration and development of an appropriate repair or replacement strategy. Sincerely, Iris Technologies, LLC John D. Risi, MS, P.E., CFEI Manager, Principal JDR:CWN:mr