Williamson and Associates, Inc. Report of Building Exterior Condition Evaluation, dated January 2 nd, (68 pages)

Transcription

1 INNOVATIVE BUILDING AND ARCHITECTURE CONSULTANTS Mr. Bud Hall Senior Vice President of construction Turnberry Associates Biscayne Boulevard, Suite 400 Aventura, FL Subject: The Nashville Hilton Downtown Dear Mr. Hall: In accordance with our agreement, IBA Consultants, Inc. has reviewed the observations and recommendations included in Williamson and Associates Report of Building Exterior Condition Evaluation, dated January 2 nd 2013 for the exterior walls, glass and glazing and roof areas of the aforementioned project and we offer the following recommendations for remediation. Referenced Documents: Williamson and Associates, Inc. Report of Building Exterior Condition Evaluation, dated January 2 nd, (68 pages) On pages 13 thru 15 of Williamson and Associate s report, conclusions and recommendations are provided for exterior wall, glass and glazing and roofing systems and summarized in line items 1 thru 9 on page 15 as follows: SUMMARY OF RECOMMENDATIONS (by Williamson and Associates): 1.) Repair EIFS (cracks, sealant, missing sealant, cleaning and apply elastomeric coating). 2.) Masonry (Repair cracks, deteriorated mortar, seal penetrations, and apply elastomeric coating). 3.) Barrier Precast (route and seal cracks, inspect and replaced failed joints). 4.) Granite (Inspect to verify sealant behind panel at precast to concrete knee wall, provide silicone sealed joints, provide weeps). 5.) Stucco (check for leakage, seal reveals, and apply elastomeric coating 6.) Windows (repair wet glazing and perimeter sealant, verify weeps are present and working. 7.) Skylights (Coordinate with Structural Engineer and Skylight Engineer).

2 Page 2 of 6 8.) Roofs (replace roofing, provide new coping, check overflow heights, install overflows, maintain roof, and consider replacement of remaining roofs years ) Retaining Wall (repair spalled and deteriorated concrete, obtain recommendations from Structural Engineer) IBA s Repair Recommendations based on Observations and Recommendations specified in Williamson and Associates Report referenced above: 1. Exterior Insulation Finish System (EIFS) Repair A. IBA concurs that any/all cracks, holes or other breaches in the exterior base and finish coats of the EIFS could permit uncontrolled water leakage to building interior if not repaired. Further, we agree all perimeter sealant work should be repaired at all locations where discontinuities (i.e.: voids, gaps, etc.) exist, or where cohesion /adhesion failure of the sealant has occurred during the in service life of the building. B. Repair all cracks, small holes, impact damage or other imperfections that exist in the base and exterior finish coats of the EIFS in strict accordance with dryvit CARE EIFS Repair Procedures (DS498) provided in Appendix D of this report. C. Repair and /or replace all sealant deficiencies with Dow 790 silicone sealant in strict compliance with Dow Corning Installation Recommendations and Dow Corning EIFS Restoration Guide provided in Appendix F and A of this report. D. After completion of EIFS and Sealant repairs, we recommend coating the EIFS with Dow Corning AllGuard Silicone Elastomeric coating for added protection against uncontrolled air and water leakage. E. During the EIFS remediation the Curtainwall window sill flashings will need to be addressed. Per the Williamson report, they will need to be removed and reworked to promote weeping of the curtainwall system. Based on Williams observations, the curtainwall and window assemblies have been wet sealed on the exterior eliminating the requirement for the systems to weep. IBA recommends further investigation of this condition to determine a proper course of action.

3 Page 3 of 6 2. Masonry/CMU Repair A. IBA concurs that a single wythe CMU wall system could permit uncontrolled water leakage to building interior thru any unsealed cracks, deteriorated mortar joints, or penetrations that exist in the exterior surface of the wall assembly. B. We recommend all existing deteriorated mortar joints be repaired or replaced in accordance with American Concrete Institute (ACI) guidelines. C. We recommend all penetrations in the exterior surface of the CMU wall be sealed with Dow 790 silicone sealant. After completion of required joint and sealant repairs, we recommend application of Dow Corning Elastomeric coating over the exterior surface of the CMU wall to provide a watertight assembly. Clean, prepare the CMU wall substrate and apply the elastomeric coating in strict compliance with manufacturers recommendations. 3. Barrier Precast and Granite Repair A. IBA concurs that the precast concrete panel system should be inspected for cracks and evidence of sealant failure at perimeter joinery. B. Route and seal cracks, and replace all defective sealant joints with Dow 790 silicone sealant. Clean, prepare concrete substrates and install sealant in strict compliance with manufacturers recommendations. Good crack repair techniques depend on understanding the cause of the cracking experienced and selecting the appropriate repair procedure that takes the cause into account. Otherwise, the repair may be temporary. We suggest further investigation be performed to verify that the cause of the cracking is not attributed to a structural issue that could require a more in depth repair procedure. Refer to the American Concrete institute publication ACI 224.R-07 Cause, Evaluation, and Repair of Cracks in Concrete Structures provided in Appendix E of this report. C. Repair and replace broken granite panels at the base of the precast wall. Inspect and verify joint formed between the base of the precast concrete panel and the concrete knee wall is properly sealed with silicone sealant to ensure water tightness. Install or repair existing sealant joint as required with Dow 790 silicone sealant per sealant manufacturer s recommendations. Seal joint formed between granite and concrete knee wall and provide weeps to drain water penetration experienced thru the granite veneer to the building exterior.

4 Page 4 of 6 4. Stucco A. IBA believes that further investigation is required to determine the source of the suspected water intrusion at this location in order to determine an appropriate plan for remediation. The detailed assessment should include forensic water testing in an attempt to determine the source of water intrusion, if any. B. If determined water leakage is occurring the stucco veneer, than we agree converting the stucco system to a barrier type system would be appropriate. Seal all reveals with Dow 790 silicone sealant and apply Dow Allguard elastomeric coating to prevent water infiltration. Install in strict compliance with manufacturers recommendations. 5. Windows/ Curtain wall Repair A. IBA recommends all glass to metal to metal to metal wet seals be inspected for proper joint design, adhesion loss, cohesive failure or discontinuities/voids in the existing sealant work. Any breaches/penetrations that exist in the surface applied wet seals could cause uncontrolled water leakage to the building interior. B. Repair or replace all glass to glass and glass to metal sealant deemed to be deficient with Dow 795 silicone applied in strict accordance with sealant manufacturers recommendations. Note: In the summary of recommendations included in the Williamson report, it states verify weeps are present and working. Further, Williamson adds weeps must be provided to prevent premature glazing unit failure. IBA disagrees with this statement, being that the system is wet sealed preventing air and wind driven water from infiltrating the system, thus eliminating the need for weeps. We recommend all exterior glass to metal, metal to metal joinery and all weep holes be sealed to prevent air and water intrusion into the glass and glazing system. C. Inspect and repair all perimeter sealant applications. IBA recommends Dow Corning 790 Silicone be used for these applications. Install in strict compliance with manufacturers recommendations.

5 Page 5 of 6 6. Roofing A. IBA has been informed that the roofs are slated for replacement. The following items should be addressed during the replacement: 1. Wind load calculations will be required to determine an appropriate roof assembly. Wind uplift pressures need to be confirmed before a roof system can be determined. 2. Secondary overflow provisions are required by use of secondary drains or scuppers. These are currently noted as missing by Williamson in some locations and possibly installed in the wrong elevation at other locations. 7. Site Retaining Wall Repairs A. Further evaluation is required to determine the extent of the spalled concrete. Structural Engineer to review and provide appropriate repair procedure. Per Williamson, the sidewalk should also be replaced. Follow the industry standards set forth by the American Concrete Institute when implementing these repairs. Reference Documents included separate from this report Appendix A: Dryvit EIFS repair Procedures Appendix B: Dow Corning Allguard Product data Appendix C: Dow Corning Allguard Application and Maintenance Guide Appendix D: Dow Corning EIFS Restoration Guide Appendix E: Dow Corning 790 Silicone Sealant Product data Appendix F: ACI 224.R-07 Cause, Evaluation, and Repair of Cracks in Concrete Structures Appendix G: Dow Corning 795 Silicone Sealant Product data

6 Page 6 of 6 Please call me should you have any questions or concerns regarding the above information. Respectfully Submitted, Reviewed by, Michael Presciti Director of Forensic Services IBA Consultants, Inc. Dave Becher Sr. Consultant IBA Consultants, Inc. The information contained herein has been prepared subject to the terms and conditions of an Agreement and is not intended for use by any recipient other than the party to the aforesaid Agreement. IBA Consultants, Inc. is not the Engineer or Architect of Record. Accordingly, IBA Consultants, Inc., its affiliates, agents, representatives and assigns do not make any representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, or suitability of the statements, conclusions, information, products, services, or related graphics, charts, tabulations or photographs contained herein for any purpose whatsoever other than that which is contained within the aforesaid Agreement. Any reliance that the recipient places on such information is therefore strictly at the recipients own risk. In no event will IBA Consultants, Inc., its affiliates, agents, representatives and assigns be liable for any loss or damage including without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from, out of, or in connection with, the use of the materials contained herein by any recipient of this information who is not a party to the aforesaid Agreement.