Mr. Eric Ryffel, Manager October 5, 2015 Sanibel Beach Club 626 Nerita Street Sanibel Island, Florida 33957

Size: px

Start display at page:

Download "Mr. Eric Ryffel, Manager October 5, 2015 Sanibel Beach Club 626 Nerita Street Sanibel Island, Florida 33957"

Camron Rich
6 years ago
Views:

1 TRC Worldwide Engineering Restoration & Inspection, LLC Fairway Lakes Drive Fort Myers, Florida Phone: (239) F: (239) C.O.A. No Mr. Eric Ryffel, Manager October 5, 2015 Sanibel Beach Club 626 Nerita Street Sanibel Island, Florida RE: SANIBEL BEACH CLUB - REAR LANAI CONDITIONS Dear Mr. Ryffel: On August 27, 2015 as requested, representatives from this office conducted limited visual observations and mechanical sounding of the (32) lanais at the (8) two-story buildings of the Sanibel Beach Club, located at 626 Nerita Street, Sanibel Island, Florida. The purpose of this inspection was to gather information that would enable us to render an opinion concerning possible deterioration and make remedial recommendations. Neither our observations nor this report is intended to cover hidden defects, hazardous materials, mechanical, electrical, or architectural features. Neither architectural nor structural record drawings were available for reference. Based on our observations, it appears the upper lanais are constructed of precast concrete slabs reinforced with pre-stressed bonded tendons with a cast in place concrete topping. The upper decks are supported by concrete beams, columns and masonry bearing walls. The lower lanais appear to be cast in place concrete slabs reinforced with steel bars. The following is a list of observations made during the conditions survey: 1. The balconies have an existing membrane coating that is deteriorated and has been worn through at several areas exposing bare concrete below (Photo #1 & 4), has started to crack through at several areas from delamination (Photo #14) and has been penetrated through by unprotected lanai furniture legs (Photo #2). 2. At several of the ground floor balconies, longitudinal cracks are noted that telegraph through the deck coating onto the slab surface (Photos #10 & 11). 3. Sections of standing water on the balconies were noted at Unit 4A, Unit 4D and other random Units (Photo #3 & 9). 4. At Unit 8B, the screen enclosure is missing several fasteners along the perimeter frame and is coming loose (Photos #6 & 7), in general the balcony screen enclosures finishes have been heavily deteriorated due to environmental and UV exposure and is peeling or faded to bare Aluminum (Photos #8 & 13). 5. Hollow sounding areas were detected in the concrete topping on the upper lanai floors as well as at the lower lanai slab surfaces. Such unsound areas are designated by diagonal hatching and a notation S/# on the attached field notes. This designation is an indication of a Concrete Spall which requires repair. Some areas of slab surface

2 Sanibel Beach Club REAR LANAI CONDITIONS October 5, 2015 Page Two spalling were noted adjacent to sliding glass door tracks such as Unit 5C (Photo #15), where the sliding glass door will need to be removed to allow for proper cleaning and treatment of corrosion on the steel reinforcing. 6. Areas of cracked and hollow stucco were noted on the exterior or corner columns at Units 2A, 2B and other selected Units at the A & B stacks (Photos #5 & 16). 7. A spalled and cracked slab edge was identified at Unit 6C (Photos #12 & 17). The condition survey performed at the (32) balconies as described herein consisted of visual observations and manual sounding of concrete, stucco and balcony deck surfaces noting areas lacking positive rebound and/or yielding a hollow echo that are indicative of concrete spalling, delaminating stucco, or slab surface spalling. Spalled slab surface areas were identified visually as raised sections below the coating and were detected as hollow areas during mechanical sounding. Areas of cracked and hollow stucco were noted at several of the buildings on the exterior corner columns that should be addressed as they are allowing for moisture infiltration beneath. Several of the slab surface spalls are located adjacent to sliding glass door tracks, which will require the removal of the door and the installation of temporary protection to perform repairs. This is required to adequately excavate concrete up to clean sections of steel reinforcing to allow for proper abrasive preparation providing durable repairs less susceptible to future delamination from corrosion of the steel continuing along the bar. Due to the regulations currently in place by the City of Sanibel Island Building Department, it is no longer possible to reinstall the existing Sliding Glass doors once removed as the Building Department now calls for them to be replaced with impact resistant rated glass. It has been recommended that corrosion mitigation anodes be utilized at the concrete repair locations due to the age of the structure and the chlorides in the atmosphere from the surrounding environment that have permeated the concrete over time. The condition of the steel reinforcing in the concrete at the spalled areas cannot be anticipated until excavation, therefore it is our professional opinion that corrosion mitigation anodes be considered to ensure to mitigate the corrosion of reinforcing and provide sound repairs. We recommend that corrosion deteriorated concrete sections should be excavated by power tools back to sound material to allow abrasive blast cleaning steel reinforcing bars free of rust and coating with an epoxy-cement bonding agent prior to forming and placing new low permeability micro-concrete mix with integral corrosion inhibiting admixture. Corrosion mitigation anodes shall be utilized at repair locations where needed based upon the condition of the exposed steel reinforcing. Any areas of hollow stucco identified shall be repaired by stripping down to bare concrete and reapplying stucco to a uniform finish to match the existing area. Based on our observations, it appears that lanai deck coatings are failing at most of the buildings, most of which will likely be disturbed by the surface repairs. Some of these

3 Sanibel Beach Club REAR LANAI CONDITIONS October 5, 2015 Page Three failures appear to have been caused by abrasions to the deck surface that penetrated through the coating down the bare concrete, while others appear to be age related. The longitudinal cracks on the ground floor slabs appear to be from erosion of the soil beneath, thus the slab is shifting for stability. Erosion underneath the lower ground floor lanais may be compensated for by drilling through the slab at a uniform grid spacing and injecting a high density water blown foam to fill in the voids. The transverse cracks between the supported slab and slab on grade should be stitched with near surface mounted rods set into shallow grooves saw cut into the deck surface across the construction joint at regular interval and epoxy grouted flush. The settled slab on grade at the outer ends may be chipped reinforced and poured back to match the level of the inner supported slab. As discussed prior, the balconies had an existing waterproofing membrane coating applied (base coat and top coat) on the decks; through visual inspection it is unclear what the age is of the existing membrane coating. In general, the membrane coating consists of a top coat and a base coat, the top coat provides the visible finish for aesthetics and protection of the base coat from deterioration from UV and weathering exposure. The base coat generally has an expected service life of 10 years, as long as the top coat is not compromised, while the top coat is to be replenished every 5 years. Due to the condition of the existing membrane coating on the decks and the concrete slab surface repairs to be carried out, it is recommended that all of the balconies be stripped to bare concrete and have a new base coat and top coat membrane system applied. Doing so would ensure the future protection of the balcony slabs from moisture and chlorides from the environmental exposure, thus maintaining the service life of the concrete. Due to the extensive areas of ponding water that were identified on some balconies during the survey from either low spots on the deck or from obstructions at the edge preventing drainage, we also have recommended that deck surface profiling be applied to balconies when the slab has been prepared to bare substrate and prior to the application of a new membrane coating system. This would be achieved by water testing of the decks to layout profiling that will provide adequate sloping for runoff and reduce standing water deposits. This will ensure that standing water on the balcony will no longer be an issue as it is detrimental to the service life of the waterproofing coating. The waterproof membrane system to be specified should include an acrylic urethane catalyzed finish coat for ease of cleaning and enhanced durability against wearing, sunlight. It should be understood that maintenance of the completed membrane system should be carried out using cleaners, primers and coatings from single source manufacturer to ensure future compatibility. During the conditions survey of the balconies, it was noted that the screen enclosures are missing several fasteners at some locations. As such, some of the frames were loose and were pulling away from the concrete that they were originally anchored into. This is important to note since Aluminum screen enclosures are used not only for the screening, but also serve as a safety barrier (railing) at the edge of the balcony. It was unclear during the inspection what

4 Sanibel Beach Club REAR LANAI CONDITIONS October 5, 2015 Page Four the age is of the existing screen enclosures, however, they show signs of heavy finish deterioration where it is both peeling and chipping, or has been wore completely through at some areas. Failures in aluminum coating could lead to increased oxidation of aluminum, especially at fastener locations where there are dissimilar materials. This corrosion would result in reduction in strength of connections that would not be readily apparent. The weakened connections may not be capable of resisting code required railing loads which would be required for the safety barrier. Hence, it is critical that the screen enclosures frames, finish, and connections be maintained in good condition and that there are periodic inspections of the railings. Based upon our observations of the existing screen enclosures, the unapparent age of the frames, and the above noted issues with missing fasteners and water lodging on the decks from lack of drainage provisions, TRC would recommend that the screen enclosures be replaced as soon as practically possible. The new screens would incorporate a 1/8 gap with PVC spacers between the fasteners and filter material between the slab and Aluminum channel to allow for adequate drainage of water from the deck. The removal of the existing screen enclosures during the restoration would allow for complete waterproofing beyond the screens and over the slab edge for complete concrete protection and new sealant dipped fasteners will ensure sufficient anchorage to the concrete with protection of the mounting holes drilled into the concrete from moisture intrusion. RECOMMENDATIONS Given the acceleration of current steel corrosion and exposure to the surrounding environmental conditions, performing the concrete repairs as soon as possible at the balconies would reduce the future scope of work as less concrete excavation will be required to clean existing reinforcing steel and reduce further delamination. Following the concrete repairs on the slab surface, stabilization of the balcony slabs on grade and removal of the screen enclosures, it is recommended that a new waterproofing membrane coating system be applied for future protection of the slab from moisture. We feel that proceeding as such would consolidate mobilization costs, promote future protection of the concrete, and ensure a uniform finish of the stacks. We recommend the following: 1. Removal and replacement of specified Sliding Glass Doors (as per City of Sanibel requirement) with temporary protection installed as noted to provide access for repairs. 2. Removal of the existing Aluminum screen enclosures and replacement with new screens following the completion of all repairs and application of new waterproofing deck coating.

5 Sanibel Beach Club REAR LANAI CONDITIONS October 5, 2015 Page Five 3. Repair of deteriorated concrete sections from reinforcing steel corrosion (incorporating the utilization of corrosion mitigation anodes if deemed necessary based on steel reinforcing condition) including the repair of hollow stucco areas. 4. Removal of existing deck coating system, preparation of decks to bare concrete substrate and application of deck surface profiling on prepared balconies to remediate ponding water locations shifting water off the balcony surface and application of new waterproofing membrane coating at all balconies. 5. Touch up painting at the balconies where repaired are to be carried out to achieve a uniform finish at all locations. We have prepared four preliminary opinion of probable costs to account for each stack of the repair scope based on our observations and recommendations in this report. Each opinion of probable cost includes budget quantities of concrete repair and related work items corresponding to the repairs contained within each balcony group. In providing these opinions of probable construction costs, it should be understood that we have no control over costs or the price of labor, equipment or materials, or over methods of pricing used by Contractors, and that the opinion of probable construction cost provided herein was made on the basis of our qualifications and experience. We make no warranty, expressed or implied as to the accuracy of such opinion as compared to bid or actual costs. Painting of the entire balcony interiors and exteriors has not been included in the opinion of probable cost as that scope is routine maintenance that should be anticipated by the normal reserve schedule and only touch up at specific repair sites will be required to maintain a uniform finish. However, TRC does recommend the Association consider performing the balcony repairs proposed herein in conjunction with painting these balcony interiors to consolidate mobilization and overhead costs that could be redundant expenses if done separately. LIMITATIONS This correspondence is intended to communicate a summary of findings at the completion of the first phase of work in anticipation that TRC will continue to provide structural engineering services in relation to the concrete repairs. As a result, this report is not a final engineering document and should be considered as preliminary in the fact that additional structural analysis and design may be required to provide any final construction documents nor is this intended to serve as testimony to any perceived deficiencies. Due to the limited scope of our investigation, we cannot attest to the structure s compliance with obsolete building codes or previously accepted construction techniques. This report does not cover hidden defects, mechanical, electrical or architectural features.

(239) 939-1414 F: (239) 278-4289 www.trcww.com C.O.A. No.

11 TRC Worldwide Engineering Restoration & Inspection, LLC Fairway Lakes Drive Fort Myers, Florida Phone: (239) F: (239) C.O.A. No Photo Exhibit Sanibel Beach Club : 15FTM626 Photo #1 Photo #2

12 Photo #3 Photo #4

13 Photo #5 Photo #6

14 Photo #7 Photo #8

15 Photo #9 Photo #10

16 Photo #11 Photo #12

17 Photo #13 Photo #14

18 Photo #15 Photo #16

19 Photo #17

Tile on Existing. Viewpoint

Tile on Existing. Viewpoint Viewpoint Tile on Existing Exterior Reinforced Concrete BalconieS By Steven C. Turner Exterior reinforced concrete balconies are often covered by tile set in mortar beds with grouted joints. These installations