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HomeMy WebLinkAboutFile Documents.701 Gibson Ave.0086-2021-BRES (25) analysis ■ support ■ sophistication 911 Marfell Street ▫Erie, Colorado ▫ 80516 (303) 665-2703 Phone ▫ (303) 665-2705 Fax February 2, 2021 Darin Eydenberg ℅ Bldg Seed Architects 417 Main Street, Suite B Carbondale, Colorado 81623 Information for Iris Project No. F20039.00: Project: Evaluation of Building Envelope and Pertinent Exterior Elements Description of Project: Bauhaus on Gibson 701 Gibson Avenue Aspen, Colorado 81611 Dear Ms. Eydenberg: In accordance with our proposal dated December 8, 2020, Iris Technologies, LLC has completed an initial inspection and evaluation of the building envelope and pertinent exterior elements associated with your home located at 701 Gibson Avenue in Aspen, Colorado. The results of this investigative effort, which included the review of past construction plans for the home, a Pillar to Post home inspection report dated September 2, 2020, sales information associated with the property contained on the “701gibson.com” website, and a joint site meeting at, and visual inspection of, the property on January 5, 2021, are presented below. PROJECT BACKGROUND The subject residential dwelling consists of a two story wood-framed structure constructed over a partial walk-out style basement foundation system built on a steeply-sloping hillside in the northeast section of Aspen, Colorado. Based on a review of the Pitkin County Assessor’s Records and original construction plans for the home, the first structure built on the subject property was construction circa 1984; termed the “Pardee Residence,” this original structure consisted of main- and upper-level living spaces constructed over a crawlspace foundation system, and the exterior of the home was finished with a combination of vertical wood siding, stucco panels and stone veneer. Then, in 2000, a substantial renovation of the home, consisting of the construction of man-level and basement living spaces that wrapped around the south and east sides of the original home, was undertaken. The “Wiener House Addition” also included the construction of three outdoor living spaces (i.e., the Sopris deck, the Independence Deck and an upper deck), and the exterior of the home was to be clad with a new exterior insulation and finish system along with limited stone masonry veneer salvaged from the home’s original construction. Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 2 of 21 As part of the most-recent purchase of the home, a general pre-purchase inspection of the property was conducted by Pillar to Post Home Inspectors on September 2, 2020; the resulting report from that inspection effort described several concerns with the exterior of the home, including poor grading and overgrown landscaping, damage to the stucco cladding across the home’s exterior walls and deck railing assemblies, and distress to the surfaces of the decks constructed over interior living space. In light of the reported concerns with the home’s exterior envelope, and to help support a new renovation of the home currently underway by Bldg Seed Architects, Iris Technologies was retained to conduct a visual evaluation of the home’s exterior to identify pertinent concerns and, where necessary, develop recommendations for the repair and/or improvement of the problematic exterior elements. PERTINENT OBSERVATIONS AND PROJECT INFORMATION The investigation of the home conducted by Iris Technologies revealed both age-related and construction-based deficiencies with the home’s stucco cladding, exterior deck assemblies and the steep-sloped and low-sloped roofing systems. General descriptions of the observed deficiencies, and recommendations for their repair or improvement, are offered below. Where deemed necessary or advantageous, recommendations for intrusive inspection of selected building assemblies are also presented. In addition, the inspection of the subject home also revealed several examples of interior water-related distress, and opinions regarding the sources and causes of the water intrusions are also presented herein. 1. The home’s exterior cladding appears to consist of a hard coat stucco system finished in varying colors and with a fine-sand float texture. The stucco cladding also exhibits varying thicknesses, with some areas reflecting a normal base-finish coat thickness and other areas suggesting that some continuous insulation may exist behind the cementitious cladding. The somewhat unconventional thicker areas of stucco suggest that those areas of cladding may include a layer on continuous insulation similar to that usually encountered with a synthetic stucco or Exterior Insulation and Finish System (EIFS). Based on a review of the “Weiner House Addition” drawings, the home was to have been finished with EIFS following completion of the 2000 renovation effort. While it unknown if an EIFS product was applied at that time, the current variations in stucco thickness may indicate that the former synthetic stucco system was covered with the current hard-coat stucco; although the presence of a layer of continuous insulation behind the stucco would be beneficial for thermal and condensation control, the lack of effective drainage behind a traditional EIFS system (if one exists) could present concerns of long-term water retention and deterioration behind the stucco. It should be noted that while some test cuts should be made in the stucco to verify its configuration and search for any evidence of long-term distress, no areas of loose or delaminated cladding (which would more clearly imply the presence of EIFS) was identified during our site inspection. 1.1. The home’s stucco cladding exhibits numerous signs of distress ranging from minor cracking at high stress locations to widespread cracking in the field areas, blistering and peeling of the cladding and discoloration consistent with efflorescence occurring through the cementitious material. Several installation-related aspects of the stucco Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 3 of 21 have likely led to or contributed to much of the observed distress, including the improper termination of the cladding too close to grade or hardscaped surfaces, inadequate slope of horizontal projections, improper isolation of the stucco from adjoining dissimilar materials, the absence of formal sealant joints at all windows and doors, and an inconsistent use of expansion and control joints across the larger areas of the cladding. While some degree of distress is notable on most of the home’s exterior walls, the distress to the stucco is the most severe on the south-facing elevations of the structure. 1.1.1. The improper termination of the stucco at or just above the surface of the exterior decks and adjoining concrete flatwork is in conflict with industry standards and local building codes, and can lead to moisture wicking up behind the cementitious cladding through capillary action. Evidence of localized calcification was noted along the base of the stucco at the West, South and Upper Decks, and where visible, accumulations of calcium were noted at several of the weep holes in the stucco’s bottom weep screeds. The lack of proper clearance between the base of the stucco and the surfaces of the decks (industry standards and local codes typically require a minimum clearance of 2 inches) also hindered the use of proper flashing at the bases of the walls, and hence intersections between the stucco cladding (on walls and deck railing assemblies) and the edges of the decks are not sealed or protected from the elements. As a result, water damages to some stucco-clad surfaces below and adjacent to the deck surfaces were noted. 1.1.2. The stucco-clad railing assemblies at the outer perimeters of the main-level patios exhibit the greatest concentration of water-related damages, including peeling and blistering of the finish coat and extensive cracking emanating from the glass panel support brackets. The patterns of efflorescence visible across the railing walls suggest water is entering the assemblies at both the tops and bottoms of the walls, and thus the improper slope/construction of the railing caps and the failure to the properly terminate the hard coat stucco a minimum of 2 inches above the surfaces of the patios are likely contributing to the water intrusions. Based on the severity of some of the distress, the potential for latent water damages to exist within the railing wall assemblies is high. 1.1.2.1. The construction of the railing caps or copings do not provide effective protection for the railing walls. The granite caps are not positively sloped and no overhangs or drip edges exist to push water away from the underlying wall assemblies. A review of the “Exterior Guardrail Cap” detail contained in the Wiener House Addition drawings reveals that the existing caps were not constructed per the plans; specifically, Detail 1 on Sheet A-55 of the noted drawing set required a positive slope of approximately 6 percent, a 1-inch overhang and a drip feature incorporated into the underside of the stone cap. The original design also called for the cap to nest over the top of the wall framing and the this 2 inch clearance may not have been part of the building code back then Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 4 of 21 space between the underside of the stone cap and the top of the exterior cladding to be treated with sealant. The existing construction of the railing wall caps do not possess these elements that would help protect the tops of the walls from moisture intrusions; as a result, latent water damages at the tops of the walls should be anticipated. 1.1.3. Several additional examples of inadequately sloped horizontal projections were also noted around the subject home, including the top of the wall at the perimeter of the spiral stairway on the Upper Patio, window sills (including two of the east-facing clear-story windows at the top of the main stairs, and the various circular-inset architectural features incorporated into the facade. Stains, cracks on the surface of the stucco and peeling/blistering of the textured finish coat were noted at several of the improperly-sloped horizontal projections. 1.1.4. The visual assessment of the home’s exterior also revealed a lack of deflector or kicker flashing at the base of the rake walls on either side of the roof overlying the main-level living room. The lack of deflector flashing has allowed storm water to flow behind the stucco cladding, resulting in visual distress to the cladding and likely some degree of structural damage to the underlying framing materials. 1.1.5. The installation of the stucco cladding also omitted industry-standard sealant joints around each window and door. While sealant has been applied around some of the fenestrations, the filet-type joints do not adequately prevent water intrusions and require regular replacement. A review of the Wiener House Addition drawings package reveals that the specified cladding was to have been installed with backer rod and sealant at all dissimilar materials; although a contractor may have believed that the substitution of stucco in lieu of the specified EIFS allowed the omission of engineered sealant joints (i.e., the stucco is believed to be more forgiving of moisture-related issues), the lack of proper sealant joints with a hard coat stucco system still violates most manufacturer’s installation requirements. 2. The visual inspection of the south and west patios revealed evidence of sustained elevated moisture levels within the tiled deck assemblies, including heavy accumulations of calcium carbonate along the grout lines, loose and partially-displaced tiles, and substantial calcium deposits within the deck’s drain assemblies. The observed evidence is consistent with poor configuration (or omission) of the decks’ drainage mats and inadequate maintenance of the internal drian piping to ensure internal weep holes remain open. Evidence of water exiting the patios at their outer perimeters also indicates improper construction of the deck assemblies and/or poor maintenance of the deck’s drainage elements. Based on the heavy accumulation of calcium deposits in the patios’ surface drains, it is likely a portion of the drainage mat has also become contaminated with mineral deposits, and hence removal and replacement of the patio assemblies are likely necessary to correct the drainage issues. Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 5 of 21 2.1. It was also noted that the thresholds of the sliding doors serving the South and West Patios are installed flush with the finished surface of the decks; such a configuration defeats any drainage mechanisms that may exist in the threshold assemblies and encourages water to seep beneath the threshold and impact the home’s interior. The potential for water intrusions beneath the thresholds is significantly increased with the sustained high moisture levels of the patio assemblies. 2.2. Observations of the Upper Patio system also revealed some concerns, including cracking of the deck’s concrete topping slab, lack of uniform heat across the patio and poor detailing at the intersection of the Upper Patio and the spiral stairway. The development of cracks in a concrete topping slab constructed over a stable structural base can stem from freeze-thaw cycles, and such a phenomenon may indicate that the deck assembly is retaining moisture (i.e., the drainage mat and/or supporting drain system has become contaminated with mineral deposits or may not have been properly constructed to support efficient dissipation of sub-surface moisture). 2.2.1. Some of the water damages to the stucco cladding observed within the spiral stairway spanning between the West and Upper Patios was traced to poor detailing between the concrete topping slab and a steel bracket secured to the edge of the Upper Patio. Specifically, an unsealed gap exists between the topping slab and the backside of the stairway’s steel bracket, and surface moisture coming from the Upper Patio topping slab is allowed to flow behind the bracket and into the stucco-clad wall. 3. The inspection of the homes roofing systems was substantially limited due to the presence of snow and ice accumulations across both the steep-sloped standing seam metal panels and low-sloped single-ply membrane. However, the visual inspection of the roofing systems did reveal some concerns, including corrosion across the metal panels, improper fabrication of the roof’s eave assembly, and poor surface drainage across the low-sloped EPDM membrane. 3.1. A significant factor in the construction of the metal panel roof system is the poor configuration of the eaves or drip edges of the steep-sloped roof assemblies. As can be seen at several locations around the home (but is most identifiable on the north wall of the garage), water flowing off the metal panels has resulted in varying degrees of staining across the underlying stucco consistent with the profile of the standing seam panels. The terminations of the metal panels at the eaves of the roof do not include any drip edge flashings, and hence no means to push storm water away from the underlying wall cladding exists. A review of the Wiener House Addition drawings revealed that an acceptable drip-edge flashing detail was provided for the 2000 renovation project, but the specified 1-inch minimum extension/drip-edge was not incorporated into the standing seam panels. 3.2. The metal roofing system appears to be at least partially ventilated, with continuous soffit venting noted across the south elevation of the home. However, while some small penetrations exist in the ridge closure strips at the top of the metal roofing Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 6 of 21 sections, the effective net-free area of the penetrations do not appear to provide adequate or balanced exhaust venting. No other inlet or soffit venting was noted on the home’s remaining elevations, and the review of the roofing details contained in the Wiener House Addition drawings indicate that most of the steep-sloped roof systems may not have been designed to support passive roof ventilation. Rather, roof details developed for the Wiener House Addition indicate that some aspects of the roof may have been constructed with continuous rigid insulation applied above the structural roof sheathing, and hence these roof sections may possess some degree of condensation control without the need for passive ventilation. 3.3. The low-sloped roof system that exist along the east side of the home does not appear to be properly sloped to its internal drains, and no heat tracing at critical areas of the roof were observed. This lack of proper drainage and snow/ice management may be contributing to the large ice formations noted along the east side of the home’s upper level and adjacent to the east-facing window serving Everly’s Bedroom. 4. The inspection of the home revealed several clear examples of interior water damages in the structure’s lower-level living spaces and its main-level Laundry Room; evidence of minor water intrusions and/or signs of condensation were also noted at the sill of the east-facing window serving Everly’s Bedroom and the northeast-facing window at the top of the East Stairs. 4.1. Water-related damages to the gypsum board ceiling in the northeast and northwest corners of Graham’s bedroom are consistent with leaks along the north edge of the West Patio. These water intrusions are likely attributable to age- and/or installation- related failures of the waterproofing membrane or improper termination of the stucco cladding at the surface of the tiled patio. 4.2. Based on exterior observations of the West Patio, the minor water-related distress noted above and below the east-facing window in the lower-level bar is likely due to unintended discharge of water from the edge of the overlying patio and/or leaks at the window. 4.3. Similar to the distress noted in Graham’s bedroom, water damages to the interior finishes along the west wall of Harrison’s Bedroom are consistent with leaks along the west edge of the South Patio. As the noted area of distress underlies the east-facing sliding door serving the main-level Living Room, the water intrusions may also be attributable to water seeping beneath the poorly-positioned door threshold. 4.3.1. Regularly-occurring water streaks down the face of the larger east-facing window serving Harrison’s bedroom were also reported during our site inspection. The chronic water-related streaks and stains are attributable to improper application of the metal head trim incorporated into the metal wall panels on the east exterior wall of the bedroom; specifically, the U-shaped metal head trim piece, which possess a series of drainage or weep holes, is oriented such that water collects in the trough-like feature; the resulting dissipation of water through the weep holes then results on the noted stains and streaks. No Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 7 of 21 water intrusions associated with the observed staining were identified, but the localized patterns of staining are likely reducing the service life of the window. 4.4. Water damages in the main-level Laundry Room, which is located along the east side of the home, are most likely the result of water intrusions through the overlying (and poorly-sloped) single-ply roofing system; however, due to the low sill height of the east-facing window in Everly’s Bedroom as well as the lack of any head flashing at the top of the noted window, the water damages in the Laundry Room may also be the result of water intrusions at the aforementioned east-facing window. It should be noted that some minor water-related distress was noted at the lower south corner of the referenced window, further suggesting that snow and ice accumulations against the window (due to the close proximity of the low-sloped roof surface) are resulting in water intrusions at the fenestration. REPAIR/IMPROVEMENT RECOMMENDATIONS The inspection of the subject property revealed three principle aspects of the home’s exterior that should be addressed as part on the ongoing renovation and improvement project to ensure proper long-term performance of the building envelope and eliminate construction aspects that could be detrimental to a future sale. These principal aspects, which include the stucco cladding, the exterior patios and the standing seam metal panel roofing system, as well as several additional localized issues, are addressed below: 1. The stucco cladding exhibits numerous deficiencies and various degrees of distress, but with the exception of the areas of blistering, the cementitious cladding appears to be well- secured and sufficiently robust. Hard coat stucco is typically more forgiving to moisture issues than a barrier-style Exterior Insulation and Finish System, and hence the existing stucco should be sufficiently repairable; however, due to the observed installation deficiencies and documented damages (both localized and general), several investigative and corrective measures should be implemented. 1.1. Due to the improper termination of the stucco cladding at the patios, test cuts through the stucco cladding at areas that exhibit damage should be made to identify the presence of any latent damages to the underlying framing. Intrusive testing should also be conducted at areas of obvious distress within the field of the stucco (e.g., at all blistered areas across the railing walls), at one or more glass railing support brackets that exhibit misalignment, at the bottoms of the improperly-flashed rake walls, and at the bases of one or more windows to determine the degree of latent water-related distress. If significant deterioration of any building materials is encountered, the removal of the stucco should continue until dry and robust materials are reached; for any significant structural damages that may be found, a licensed structural engineer should be consulted. 1.2. Cracking of the stucco can be seen on all elevations of the home, with substantial cracking noted on the south and west sides of the structure. The application of horizontal and vertical control joints varies across the home’s elevations, and the Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 8 of 21 patterns of cracking do not appear to be consistent with the density of control joints. The extensive field cracking across the stucco suggests that at least some of the cementitious cladding may have been applied over a layer of rigid insulation in a fashion similar to an exterior insulation and finish system (i.e., synthetic stucco); although the presence of continuous insulation across the exterior walls provides improved condensation control, the more extensive expansion and contraction that can occur with hard coat stucco placed over continuous insulation will typically result in widespread cracking despite the application of expansion/control joints and a crack-control mesh embedded in the base coat. Prior to implementation of the stucco repairs, test cuts should be made in areas of the field that exhibit the greatest cracking to determine if the composition of the cladding is contributing to the thermally- generated distress; if the presence of rigid continuous insulation is identified, conversion of the cladding system to a true water-managed EIFS system should be considered. 1.3. To meet industry standards and all applicable codes, the bottom edges of all stucco- clad walls that intersect the South, West and Upper Patios, as well as any abutting concrete flatwork, should be cut back and reinstalled to attain a minimum of 2 inches of clearance to the adjoining horizontal surfaces. At the South and West Patios, and before establishing the 2-inch clearance, the stucco should be cut up 12 to 18 inches to facilitate the installation of new base flashing integrated into the tiled patio assemblies and to ensure proper extension of waterproofing materials up the vertically- intersecting walls. At the Upper Patio, the stucco should also be cut up several inches to evaluate the flashing and waterproofing materials that have been incorporated into the concrete topping slab and adjoining walls; as deemed necessary, additional flashing elements should be installed over the vertical edges of the patio’s waterproofing membrane to provide protection to the waterproofing materials when the stucco is reinstalled to the required 2-inch clearance. 1.4. It is the opinion of Iris Technologies that large portions of the distress exhibited by the patio railing walls can be attributed to the poor configuration and construction of the railings’ stone caps. As such, it is further our opinion that all the railing caps should be reconstructed to more closely match Detail 1 on Sheet A-55 of the Wiener House Addition drawings. 1.5. All horizontal projections in the stucco system greater than 1 inch wide should be reconfigured to provide a minimum positive slope of approximately 1 inch vertical in 6 inches horizontal; if the projection is less than 1 inch wide, or if the recommended slope is deemed visually unacceptable at some locations, the surface of the stucco should be sloped as great as possible. If achievable, the depth of the circular features currently incorporated into the home’s façade should be reduced to lessen the impact of the resulting horizontal projections. 1.6. As stated above, the installation of the windows and doors around the subject home, as well as numerous other penetrations and intersections of the stucco with dissimilar materials, lack proper and maintainable sealant joints and/or flashing elements; while Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 9 of 21 the stucco may have been sufficiently forgiving to prevent any long-term rot or decay to the framing materials at the home’s fenestrations and major penetrations, the continued absence of industry-standard sealant joints (and lack of sufficient regular maintenance of the poorly-configured filet joints) will eventually result in some degree of latent distress. For compliance with manufacturer’s installation requirements, the stucco should be cut back around each window and door, proper connection between any underlying weather-resistance materials and the fenestrations confirmed (and improved as necessary), and the stucco then reinstalled up to approximately ⅜ to ½- inch away for the window/door frames. Prior to the application of the new finish coat, closed-cell backer rods and a UV-stable elastomeric sealant shall be placed in the newly-created gaps around the fenestrations. 1.6.1. A similar approach to modifying the stucco should also be conducted at all substantial penetrations, including the large copper pipe on the west wall of the main-level powder room and at each of the glass railing support brackets. 1.7. Due to the extensive stucco repair and improvement measures described above, the entire stucco system will likely require a complete base skim coat and finish coat to achieve proper color and texture matching. To further reduce the potential for cracking to reoccur across the field of the stucco, a reinforcing “crack-mesh” should be embedded in the base coat before applying the colored finish product. 2. Due to the obvious distress exhibited across the South and West Patios, as well as the significant accumulation of calcium deposits within the interior drain assemblies, it is the recommendation of Iris Technologies that the two main-level exterior living spaces be fully removed and replaced. While the deck details contained in the Wiener House Addition drawings are generally correct and adequate for the reconstruction of the patios, compliance with the plans should be confirmed during removal of the deck assemblies, and any changes or improvements to the patio assemblies needed to achieve proper and effective drainage of the deck systems should be implemented. Due to the inherent maintenance issues associated with a deck system comprised of tile or stone installed over mortar beds, the use of pedestal support systems or application of brick pavers over sand beds should be considered to eliminate the deposition of calcium carbonate across the drainage medium and within the internal drain assemblies. The development of proper and complete details for the reconstruction of the South and West patios, including the redesign of the door thresholds that abut the patios, is outside the scope of this initial report; however, based on what is encountered during the removal of the existing patios, Iris Technologies can assist in the development of formal construction details and specifications for new exterior living spaces upon request. 2.1. The Upper Patio presents with cracking that suggests minor freeze-thaw-related expansion/contraction of the patio’s concrete topping slab, and as described above, this phenomenon may indicate cyclically-elevated moisture levels within the slab. Although the slab does not present with sufficient distress to justify its removal and replacement, the effectiveness of the drainage plane beneath the topping slab, as well Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 10 of 21 as the performance of the patio’s snow-melt system, should be evaluated. Specifically, the internal drain systems should be scoped to assess the degree to which the drain assemblies and associated piping may have become obstructed with mineral deposits, and the drain assemblies should then be thoroughly cleaned to confirm any secondary weep holes are open and effective. If excessive deposits are encountered, a small section of the topping slab surrounding each surface drain should be carefully removed (without damaging the snow melt tubing) to confirm proper installation of the drainage mat and evaluate the degree to which the drainage medium may be fouled. If significant deficiencies or concerns are discovered, the removal and replacement of the concrete topping slab may be necessary. 2.2. Due to the surface cracking present across the Upper Patio’s concrete topping slab, it is understood that some form of coating may be applied to the surface of the patio. While the application of some type of coating will more readily allow for test cuts to be made at the surface drains (if deemed necessary), the application of a coating must be accompanied with some means to decouple the new coating from the cracked concrete surface to prevent the existing cracks from telegraphing through the new finish. 2.3. Additional investigative efforts, including the removal of a portion of the abutting concrete topping slab, should be made to fully identify the deficiencies noted between the Upper Patio’s topping slab and the structural steel bracket securing the spiral stairway to the patio. At a minimum, some means to seal the noted intersection or reconfigure the connection to prevent water from flowing behind the bracket should be implemented. 3. The limited inspection of the standing seam metal roof assemblies revealed some limited areas of corrosion, and these areas of distress should be more closely evaluated without snow on the steep-sloped roof surfaces (and regularly-monitored to identify any worsening conditions). The primary concern with the metal panel roof systems, though, involves the lack of proper eave and drip-edge flashing elements; to prevent or reduce the staining experienced on the faces of the underlying the stucco-clad walls, all eaves of the metal panel roof system should be reconfigured to match Detail 14 depicted on Sheet A-55 of the Wiener House Addition drawings. 3.1. Where passive soffit/intake ventilation has been provided for the steep-sloped roof assemblies, proper and sufficient ridge/exhaust venting should be confirmed and/or incorporated into the roof systems. Where ridge/exhaust venting should exist, the upper portions of the standing seam metal panels should be partially disassembled to confirm adequate pathways exist for the passive air movement, and the ridge assemblies should be modified to provide a maximum of 15 square inches of net free ventilation per linear foot. 3.2. As identified in the September 2, 2020 home inspection report produced by Pillar to Post, the low-sloped roof system exhibits some poorly-sloped areas where storm water can accumulate, and our winter-time inspection of the roof revealed ice accumulations at several locations across the single-ply membrane. To extend the service life of the Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 11 of 21 roof membrane, efforts to acquire a proper and positive slope across all areas of the roof should be considered. In addition, the application of heat tape or heated mats (e.g., Heatizon’s Z-Mesh heat mat) at critical areas of the low-sloped roof system should also be pursued, with emphasis applied to the areas along the southeastern- most portion of the roof (i.e., just below the eave of the adjoining steep-sloped roof surface) and in front of the window serving Everly’s bedroom (due to the low height of the window sill). In addition, heat tape or heat mats should be applied at any surface drains and along any valley-like flow paths leading to the area drains. 4. The inspection of the property, while limited by the presence of snow on the roofs, did reveal a couple of additional issues that should be addressed. Principally, the east-facing window serving Everly’s bedroom, which is partially inset into the face of the stucco, lacks any form of head flashing to divert water away for the top of the aluminum casement-style fenestration. As a result, evidence of water streaks emanating from the top of the window suggest that water may be entering across the top of the windows during periods of moderate to heavy precipitation. As part of the recommended effort to create formal sealant joints around all of the windows and doors, metal head flashing should be incorporated into the subject window as well as at any other similarly-configured fenestrations. 4.1. The inspection of the low-sloped roof assembly at the east side of the home also revealed at least one instance of improperly-wrapped wood blocking or trim. Specifically, along the side of the semicircular feature at the northeast corner of the low-sloped roof, a section of wood blocking extends beyond the stucco cladding, and a metal flashing element that is likely incorporated into the roof’s single-ply membrane abuts the face of the wood blocking; however, the flashing does not wrap around the top of the wood blocking, leaving the blocking and the abutting stucco exposed to moisture. In addition to correcting this deficiency, an effort to identify and correct any similarly-configured flashings should be pursued. 4.2. The configuration of the metal panel system applied to the east-facing wall of Harrison’s bedroom should be modified to provide proper head-style flashing along the top of the large east-facing window; proper termination of the metal panels at the top and bottom of the subject wall should also be confirmed. 5. The inspection of the home did not afford a thorough evaluation of the composition of the wall and roof assemblies, and hence it is not known if the construction of the building envelope incorporates any means of condensation control. The details associated with the Wiener House Addition drawings do indicate the roof assemblies were to be constructed with either continuous insulation above the structural sheathing or passive ventilation incorporated into the roof cavities (both of which constitute at least a partial means of condensation control), but the as-built condition could not be confirmed. Similarly, the wall details depicted in the Wiener House Addition drawings also indicate that the exterior walls were to have some attempt at condensation control via the continuous insulation incorporated into the exterior insulation and finish system; however, as it does not appear the home was consulted with a synthetic stucco system, it is unlikely that uniform Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 12 of 21 continuous wall insulation exists. While the home’s exterior wall assemblies may be performing adequately, any intrusive testing conducted as part of the home’s on-going renovation project should also look for evidence of condensation-related distress; further, any interior modifications to the home’s exterior walls might also afford an opportunity to evaluate the condition of the wall assemblies, and any evidence consistent with condensation or obvious air and vapor gaps should be addressed. If significant moisture- related distress is found in the home’s exterior envelope, or if any substantial changes to the home’s interior humidity levels are anticipated, a more in-depth assessment of the exterior roof and wall assemblies should be conducted. All comments made in this document are based on the conditions observed at the time of the site investigation 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 proposed repair and improvement measures described herein. Sincerely, Iris Technologies, LLC John D. Risi, MS, P.E., CFEI Manager, Principal JDR:CWN:mr Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 13 of 21 Figure 1: Overview of the Bauhaus property located at 701 Gibson Avenue in Aspen, Colorado. Figure 2: The stucco cladding was improperly terminated too close to the surfaces of the home’s three exterior patios; note too the staining emanating from the inadequately-sloped architectural features and the non-uniform application of control joints in the field of the stucco. Figure 3: Improper termination of the stucco at the exterior patios has prevented proper flashing and waterproofing at the perimeter of the patios’ tiled surfaces; note the resulting water damages to the abutting stucco. Figure 4: The construction of the coping features on the patios’ railing walls does not prevent water from entering the wall assemblies and is not consistent with the detail provided in the Wiener House drawings. Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 14 of 21 Figure 5: Evidence of water damages stemming from failures in the patio waterproofing systems can be seen in the abutting stucco cladding. Figure 6: This distress to the stucco is likely the result of improper detailing at the deck-to-wall connection and/or the failure of the patio’s waterproofing system. Figure 7: View of severe blistering and peeling of the stucco cladding on a patio railing wall; these water- related damages are due to improper termination of the hard-coat cladding at the surface of the patio and/or the poorly-constructed cap at the top of the wall. Figure 8: The misalignment of several of the glass- railing support brackets may indicate that the underlying wall sheathing has failed due to water intrusions behind the cementitious cladding. Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 15 of 21 Figure 9: The extensive water-related damages exhibited on this wall stem from several deficiencies, including improper termination of the stucco at the patio, lack of a positive slope across the overlying stone cap and a poorly-located horizontal control joint. Figure 10: View of severe blistering stemming from water intrusion at the edge of the patio and possible failure of the patio’s waterproofing system; note the heavy calcium accumulation at the edge of the patio, indicating a sustained moisture levels within the body of the patio. Figure 11: Poor detailing at the perimeter of the spiral stairway has led to corrosion of the stairway’s steel connection plate. Figure 12: The configuration of materials at the edge of the concrete slab of the Upper Patio is allowing water to seep behind the underlying steel connection plate and into the abutting stucco-clad wall; blisters in the finish of the stucco cladding were noted within the interior of the spiral stairs. Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 16 of 21 Figure 13: The lack of an adequate slope across the top of the guardrail surrounding the spiral stairway has also likely contributed to water intrusions into the wall assembly. Figure 14: This area of stucco cladding at the Upper Patio appears to have been terminated below the surface of the concrete topping slab; as a result, the stucco just above the concrete slab has blistered and failed. Figure 15: The depth of, and lack of sufficient slope within, the home’s circular architectural features has resulting in surface and latent damages to the underlying stucco. Figure 16: Two of the north-facing windows over the garage lack hard-surfaced or properly-sloped sills. Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 17 of 21 Figure 17: View of distress to the stucco cladding due to improper termination of the cladding at dissimilar materials. Figure 18: Evidence of failed stucco could be seen at the base of the south-facing window serving Darin’s office; notes too the lack of proper sealant joints around the perimeter of the window. Figure 19: The lack of proper deflector flashing at the base of the rake wall along the east edge of the roof overlying the main-level living room has resulted in water damages to the stucco cladding; this same failure also exists at the west side of the living room roof assembly. Figure 20: These water damages at the front of the home are likely the result of leaks behind the stucco cladding originating at the base of the overlying triangular window. Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 18 of 21 Figure 21: This wood blocking at the northeast corner of the home was not properly flashed. Figure 22: Stains beneath the northeast corner of the West Patio suggests water is passing through the overhanging granite tile and bypassing the waterproofing system that should exist beneath the tile assembly. Figure 23: Signs of water flowing behind the metal panel positioned beneath the edge of the West Patio was also noted; evidence of resulting water-related distress was noted at the interior sill of this window serving the home’s lower-level Bar area. Figure 24: The exterior metal wall panels installed on the east wall of Harrison’s bedroom was improperly fabricated with an inverted channel just above the large window; the small drain holes in the channel eventually allow water to dissipate, but the draining water creates unsightly stains across the window. Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 19 of 21 Figure 25: Distress to the stucco cladding stemming from improper termination at the concrete flatwork and inadequately sloped window sill was noted beneath the south-facing Powder Room window. Figure 26: The purpose of this copper pipe, which penetrates the west wall of the home’s main-level Powder Room, is unknown. The negative slope of the pipe and lack of a proper sealant at its penetration in the stucco cladding has likely allowed water to enter the structure. Figure 27: The heavy calcium accumulations visible across the South Patio indicate that the drainage plane beneath is faulty; the lack of uniform snow dissipation across the patio suggests that at least some aspect of the embedded snowmelt system has also failed. Figure 28: Adhesive failures of the granite tile along the east edge of the South Patio further suggests a consistently high moisture content within the deck assembly. Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 20 of 21 Figure 29: View into the surface drain at the center of the South Patio; the sustained high moisture content within the patio assembly has resulted in heavy accumulations of calcium within the drain piping. The lack of proper maintenance of the drain system has likely exacerbated the failure of the patio. Figure 30: The elevation of the threshold of the west Living Room sliding door is too low, and any weep mechanisms incorporated into the threshold have been blocked; note the presence of biological growth stemming from the high sustained moisture content of the patio assembly. Figure 31: Poor fabrication of the eave of the standing-seam metal roof system results in water cascading down the north wall of the garage; similar albeit less severe staining was also noted other areas of the home that lie beneath a roof eave. Figure 32: The eaves of the metal panel roof systems lack any appreciable drip extension to effectively push storm water away from the face of the underlying stucco. Bauhaus on Gibson – Evaluation of Building Envelope February 2, 2021 Page 21 of 21 Figure 33: The existing metal panel roof system is exhibiting minor corrosion; although the Figure 34: While some of the home’s soffits contain continuous venting, the only ridge venting may consist of these relatively small and widely-spaced vent holes. Figure 35: Detail 1 on Sheet A-55 of the Wiener House Addition drawings depicts how the cap features of the patio railing walls should have been constructed in 2000; note the positive slope of the stone cap, overhang of the coping and integrated drip edge. Figure 36: Detail 14 found on Sheet A-55 of the Wiener House Addition drawings indicates tha the standing-seam metal panel roof system shod have been fabricated with integral drip flashing.