Structural Condition Assessment ‐ Phase II Update – Sep 14, 2022, HOA Meeting

STRUCTURAL CONDITION ASSESSMENT ‐ PHASE II UPDATE September 14, 2022, HOA MEETING

 CONCRETE TESTING

• As described in the August update, we have retained a testing laboratory to implement the concrete testing program prepared by our structural engineering consultant. The testing program is designed to sample and test concrete in areas where decades of infiltrating water have affected the catacomb floor and garage ceiling.

• Concrete coring in the garage and catacombs was conducted on August 11 and 12, and half‐cell testing and rebar exposure chipping were completed the week of August 14. The structural engineer was then on site August 18 to inspect the exposures.

• Preliminary observations following the sampling program indicate that overall concrete strength is good; however, there is some corrosion of the steel reinforcement bars and elevated chloride levels throughout the slab (which is a catalyst for corrosion).

• A detailed structural condition report providing full results of the concrete testing work and recommendations for concrete repairs will be completed by the end of September. It is expected the structural engineer will recommend that some localized slab repairs be implemented.

• After receiving the report, we will identify qualified concrete restoration contractors and request competitive bids to repair the damaged concrete per the structural engineer’s recommendations.

• It’s expected the shoring remain in place until the repairs are completed. 

WATERPROOFING EVALUATION

• Our waterproofing consultant completed their investigation of the catacombs and parking structure the first two weeks of August, and test trenches along the south side of Tower 1 and the west side of Tower 4 were completed September 8‐9, 2022.

• Standing water and water stains were observed and documented in the garage and catacombs, providing strong evidence of the location and nature of our water intrusion and leakage problems. Nearly all the water intrusion is from the catacomb walls, with the garage walls being relatively dry.

• The test trenches revealed that several coatings of inter-layered asphaltic emulsion and fiberglass mesh were applied as waterproofing to the catacomb and garage walls during original construction, but over the past 45‐50 years this waterproofing has significantly degraded and in places has been compromised by root intrusion.

• A similar but more robust asphalt‐fiberglass waterproofing was found on top of the podium slab; this also being in a degraded condition.

• Our consultant is currently compiling their field observations and will present their preliminary findings to the HOA Board of Directors on September 21.

• Concrete dust was noted in the garage during the rebar exposure chipping. We consulted with a Certified Industrial Hygienist and were assured that the relatively short duration and low concentration of generated dust did not create a significant health and safety concern.