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HomeMy WebLinkAboutEngineer's Letter-Structural Repairs and Observations 08.01.2023 August 1, 2023 Tara Dakides 1927 Panorama Drive Carbondale, Colorado 81623 tdakides@gmail.com RE: Structural Repairs and Observations Dakides Zamansky Barn, 1212 Panorama Drive, Carbondale, Colorado - Garfield County Evolve Projects #17.005C, 20.165C & 23.063C Tara, As requested, we performed a site observation on July 17, 2023 to review the current condition of the exterior structure, so as to assess the need to repair framing members exposed to the elements over a period of several years. We have summarized our recent observation and recommendations within. As well, we have included some content still needing to be addressed from previous observation and repair recommendation letters. Detail references noted within are from our structural permit drawings dated September 11, 2017. Please note, building envelope concerns noted in our previous reports have not been readdressed herein. We have solely addressed structural material, member and connection repairs required. As a comprehensive building envelope is essential for adequate protection of the structure, it is our recommendation that an architect, waterproofing and/or building envelope specialist review and address the building for any concerns in that r egard. New Framing Repair Recommendations We reviewed the exposed framing conditions at the low roofs and deck. It is our professional opinion that, due to the extent of weather-related deterioration of the framing observed at the low roof construction, it may be most cost effective to replace the entire low roof system. Alternatively, you could seek the services of an independent expert in deteriorated timber evaluation to more thoroughly evaluate each situation to determine whether the affected members should be replaced or if any of the noted existing framing can be considered structurally sound. • Exposed and covered low-roof rafters show signs of deterioration due to moisture (Photo 1). The affected members may need to be replaced with equivalent framing. Since rafters are cantilevered over the exterior beams and extend back to the house wall, the entire rafter sections may need to be replaced if the exposed ends are determined to be structurally compromised. • Exposed unprotected rafters show signs of significant deterioration due to moisture exposure and excessive drying (photo 4). The affected members may need to be replaced with equivalent framing. • Exposed exterior beams show signs of deterioration due to moisture and drying (photos 2, 3, 4, and 5). The affected members may need to be replaced. If the contractor determines in the field that the beams, or specific beam spans, are salvageable, Evolve Structural Design (ESD) should be contacted to re-evaluate the members for structural integrity considering the degree of deterioration present. • Exposed wood posts in some cases exhibit some degree of deterioration (moisture penetration, primarily at beam/post connections) and possible splitting. Posts that are painted should have paint removed to facilitate a Dakides Zamansky Barn - Structural Repairs, July 2023 - Page 2 of 4 more accurate evaluation of wood conditions. At beam/post steel connections, all bolting should be reviewed for tightness of fit; moisture intrusion and/or excessive drying, causing wood shrinkage, may result in inadequate bolt bearing conditions in the wood members. (See photos 1, 2, 3 and 5.) • The glulam hip beam installed at the northwest corner of the low porch roof has been exposed to weather and appears to have moisture damage at the surface (photo 4). It is not clear that this beam is an exterior-grade wood member, and thus may be compromised by excessive weather exposure. The Contractor should verify the type of glulam provided and notify ESD to evaluate conditions if not an exterior grade product. In addition, the beam shall be confirmed to meet or exceed our specification of a 6x14 or 8x12 Douglas Fir #1 timber beam. • Some low roof sheathing exposed to weather exhibits deterioration due to moisture penetration (photo 1). Roof sheathing classified as ‘Exposure 1’ grade are designed to resist exterior exposure for short periods of time (normal construction periods) and are not intended for prolonged exposure. The affected sheathing panels should be replaced with equivalent material and covered as soon as possible with waterproof roofing and appropriate flashing at the perimeters of the roof. • Roof overhang soffits and soffit vents exhibit areas of deterioration (photo 6). Soffit material in these locations should be replaced as needed to provide solid enclosure for the roof overhang, with vents as required. • All ledger attachments to the SIP walls shall be field verified as required by SIP supplier specifications and ESD details (7/S2.2; 10/S2.1). Other Items: • The sliding glass door header at the upper-level southwest corner support is unclear at each end of the door (photo 7). The contractor shall verify that the header and support members are in compliance with the SIP panel supplier shop drawings. Construction in conflict with the shop drawings should be addressed by the SIP panel supplier. • We were informed that all of the exterior wall waterproofing material (Tyvek) will be removed to allow further assessment of the existing exterior sheathing and SIPS. Additionally, all windows and doors will be temporarily removed and reinstalled to assess for any deterioration due to water infiltration and to allow for proper flashing and building envelope continuity. It currently appears to be incomplete or compromised at various locations around the building (photos 8 and 9). As noted in the report issued by SBSA dated March 22, 2019, flashing at wall openings and roof edge areas do not comply with typical construction standards. As needed, the SIP supplier should be contacted to assess the condition of the panel s at these locations for effects of weather and water intrusion on their panels and to make appropriate repair recommendations. • Exterior upper level deck exhibits signs of moisture damage on the underside (refer to SBSA report dated March 22, 2019). Structural members affected should be confirmed by Contractor to be free of moisture, affected sheathing replaced, and finish materials above re-applied as needed to provide a waterproof surface. • Several areas of the main level concrete slab and exterior drainage issues should be addressed to prevent water-related issues at the foundation level. Please refer to SBSA report dated March 22, 2019. Please refer to the attached Addendum 1 for photos referred to above. Previous Repair Recommendations & Observations (Letter dated November 23, 2020) We reviewed the SIP section between the two southmost garage doors at the east exterior wall. The panel was compromised at the 6x6 post supporting the W14x48 steel beam in the upper level floor. A maximum of approximately ¾” width of the 6x6 post and a 2x6 end of panel stud just south of the 6x6 post were cut through for a vent pipe penetration. A 2x6 stud appears to have been installed later. • The previously installed 2x6 stud and the original panel end stud should be replaced with new 2x6 studs. Prior to installing the new studs, the affected section of the 6x6 shall be filled in with a wood block matching the void shape. The wood block and all studs shall be adhered fully to the 6x6 with Loctite PL Premium Fast Grab or equal. All new lumber shall be Douglas Fir #1 grade. Dakides Zamansky Barn - Structural Repairs, July 2023 - Page 3 of 4 • All affected insulation, adhesive, sheathing and seam tape shall be repaired with materials approved by the SIP manufacturer, Premier SIPS. • The existing steel beam shall be adequately shored during the repair. Temporary shoring is the responsibility of the Contractor. All damaged grout between sill plates and top of foundati on wall shall be removed and repointed. All interior bearing walls shall be shimmed at each stud and post/column, matching their width and depth at a minimum. Upper level deck railing posts were installed through the deck sheathing with no visible connection to deck framing. The base of the railing posts should be adequately connected to deck framing to support them from lateral movement. This can be achieved with blocking, screws, and/or premanufactured connectors. The glulam hip beam installed at the northwest corner of the low porch roof shall be confirmed to meet or exceed our specification of a 6x14 or 8x12 Douglas Fir #1 timber beam, omitting the bent steel beam per our previous design. (Note: A flush (2) 2x8 beam along Grid E shall support the 2x8 rafters’, as noted in the letter dated November 23, 2020, has been field-modified as a dropped heavy timber beam (Photo 4). This beam shall be field- verified for size, timber grade, and current condition.) It was previously noted on site that water had infiltrated into the beam pocket as it had not been properly sealed up after installation of the beam. Any damage to the affected SIP wall sections should be repaired as required. The non-bearing interior walls were installed up to the underside of the premanufactured roof trusses. Per our permit drawings the contractor should have allowed for a ½” slip joint at the bottom of trus ses to the top of nonbearing walls. This allows the roof trusses to be loaded as designed per the manufacturer. In order to conform to their design, the top of the interior walls should be lowered by a ½” and the non-bearing walls should be braced perpendicular to their length by a slip connection. This can be done by using premanufactured slip connectors or by framing a slip detail with accessory 2x framing. It can be confirmed with the truss manufacturer whether the installed framing is required to be modified or is acceptable as built. It was observed on site that roof diaphragm blocking specified in detail 5/S2.2 of our permit set was not installed. This shall be installed as noted along gable end walls to provide adequate load transfer between the roof diaphragm and the supporting walls. The exterior southwest corner of the concrete foundation shall be repaired. • Confirm that the holdown anchor was properly installed into the concrete and to the framing anchor per the SIP manufacturer’s drawings. • Prepare the repair area per the grout manufacturer’s specifications, cut out a squared off portion of concrete at the corner, removing all affected material and exposing the reinforcing with approximately 1 inch minimum clearance around the reinforcing, taking care not to damage the reinforcing. The bottom of the void shall be approximately level and the exposed faces of concrete shall be left roughened. • Fill the corner void with grout, such as Ardex FDM or equal, installed per the manufacturer’s specifications. If depth is greater than 4 inches, grout infill shall contain aggregate per the manufacturer’s specifications. Also, other locations at the top of the foundation walls, near wall ends, corners and intersections, had visible honeycombing and void pockets. The affected areas shall be filled with repair grout such as SikaQuick VOH mortar or equal, installed per the manufacturer’s specifications. Upon completion of all items as noted, it is our opinion that the observed structural elements will be adequate for use as a residential structure per Garfield County requirements. Please be aware that the opinions expressed herein are based on limited, non-intrusive observations. If other conditions are discovered during the construction process, these opinions may be revised. As requested, we will follow up with subsequent site observations and field reports to document progress. Dakides Zamansky Barn - Structural Repairs, July 2023 - Page 4 of 4 Should you have any further questions regarding this matter, please feel free to contact our office. Sincerely, Drafted By: Evolve Structural Design LLC Sara Mickus, P.E. Oliver Rice, P.E. Principal Senior Engineer 08/01/23 August 1, 2023 Structural Repairs, Addendum 1 Dakides Zamansky Barn, 1212 Panorama Drive, Carbondale, Colorado - Garfield County Evolve Projects #17.005C, 20.165C & 23.063C PHOTO 1 PHOTO 2 Dakides Zamansky Barn - Structural Repairs, Addendum 1, July 2023 - Page 2 of 6 PHOTO 3 PHOTO 4 Dakides Zamansky Barn - Structural Repairs, Addendum 1, July 2023 - Page 3 of 6 PHOTO 5 PHOTO 6 Dakides Zamansky Barn - Structural Repairs, Addendum 1, July 2023 - Page 4 of 6 PHOTO 7 PHOTO 8 Dakides Zamansky Barn - Structural Repairs, Addendum 1, July 2023 - Page 5 of 6 PHOTO 9 PHOTO 10 Dakides Zamansky Barn - Structural Repairs, Addendum 1, July 2023 - Page 6 of 6 PHOTO 11