(4020-NY) ARCHITECTURAL BUILDING INSPECTION ASSESSMENT AND REPORT

Transcription

1 FEMA Task Order 12-J-0001 (4020-NY) ARCHITECTURAL BUILDING INSPECTION ASSESSMENT AND REPORT Orange County Government Center 255 Main Street, Goshen NY February 15,

2 INDEX and TABLE OF CONTENTS I. BACKGROUND AND BUILDING HISTORY II. EXISTING CONDITIONS III. ARCHITECTURAL INSPECTION S AND WEATHER EVENTS DAMAGE I. BACKGROUND AND BUILDING HISTORY IV. CONCLUSIONS 2

3 I. BACKGROUND AND BUILDING HISTORY This report is a visual building condition architectural assessment with emphasis on the storm caused damage on behalf of FEMA in response to claims by the Orange County Government for the Orange County Government Building. The building was constructed in 1967 and designed by The Architect Paul Rudolph. The building size is approximately 160,000 square feet of space separated into three components called Divisions that are connected by corridors and are grouped around a center courtyard. The building s structure is reinforced concrete with two way reinforced floor and roof slabs and rectangular concrete columns and shear caps. The perimeter walls are predominantly split concrete block cavity walls. Large light monitors throughout the building extend above the roof to bring light into the interior. The building predates the energy crisis and mandates on energy consumption, as well as, ADA laws of the 1990 s. Hence these later enhancements are not apparent in the present building. The general opinion of the assessment team based on visual evidence and lack of building documentation is that the building has had few significant upgrades over the years. It is surmised that the roof was replaced at some time and the previous reports by the Owner s consultants indicate that structural work was done in the 1990 s, the records, documents, and construction records are not available. Modifications to the building observed are deviations from the original plans and are predominately interior re-arrangement of offices and service spaces from the original drawings and again no documentation was available. From the previous reports by the Owners Consultants representatives dated August 16, 2011, September 9, 2011, and November 2011, as well as, complaints from the Owners, employees, and published newspaper articles documents the building s long history of roof leaking and water penetration into the interior of the building that predates the storms. The extreme weather events of tropical storms Irene on August 28, 2011 and Lee on September 5,6,7, and 8 produced large amounts of water and wind in rapid secession on the building structure and site overwhelming the existing building envelope, especially the roof. II. EXISTING CONDITIONS A. Existing Building Structure and Envelope Prior to FEMA s site assessment, the assessment team received the previous assessment reports by the county s consultants. Further, in meetings with the County the assessment team requested the records of major site, building envelope, and equipment repairs or replacement drawings including records of the roof repair, replacement, and warranties. The county indicated that these records were not available from the files. 1. Structural Roof System Floor and roof slabs are two way reinforced concrete slab 6 inches thick. Keys between the slab and vertical walls were observed in some areas on the construction documents but in general no expansion joints or construction joints were shown. General industry standards at the time construction documents were prepared did not show concrete demarcation lines (cold joints) between the horizontal and vertical pours. These items were relegated to the shop drawings 3

4 to allow the contractor to control the extent and size of the concrete pours during construction. These drawings would of been reviewed by the project s architects and engineers and when approved formed the final basis for the installation. The approved shop drawings were not available for review. The reinforcing was extended vertically from the horizontal slabs and cast with the vertical wall to form the light well walls but the junction between the vertical and horizontal concrete was a cold joint. There was no evidence of a water bar installed between the horizontal slab and vertical wall. The lack of this element and the method of installing the roof figures prominently in the water infiltration problem and efflorescent described in the architectural narrative and photographs. 2. Building Foundation System From the Owner furnished documentation, The foundation is a combination of spread footing, grade beams and columns. There was no evidence of slab settlement at the lowest levels as a result of the flooding and the building structure is intact. The Owner s consultant reports indicate that in their opinion modifications and component replacement is required for the roof slabs and their components. However,the visual inspection revealed that the storms did not compromise the existing structural systems and the roof is in basically the same condition as it was prior to the storms. 3. Building Exterior Wall Construction and Flashing: In general and based on the building s construction documents, the exterior walls are cavity walls 10 inches to 14 inches thick with split faced concrete block on the exterior and either split faced, plain concrete block, or cast in place concrete on the interior. The walls show a two (2 ) cavity with 1 solid insulation terminating near the roof with plastic flashing at the bottom of the cavity wall and weep holes ( to drain the cavity ) extending to the outside. The first weak link in the integrity of the wall is the base flashing. It is called plastic in the documents and very well might be an early pvc product called Neverstal in general use in the late 1960 s and early 1970 s. The product is dimensionally unstable ( it shrinks) and becomes brittle over time. Because of this flashing there is reason to believe that the existing cavity wall flashing today is non- functional. C. Roof System and Drains The waterproofing layer of the existing roof system is a loose laid membrane roof over 2 inches of rigid insulation and utilizing 2 inches of light weight concrete fill below the insulation poured directly on the structural concrete deck. The ballast is 2 inches thick concrete block approximately 12 inches square with drainage grooves, set tightly together, and dyed black. The ballast has a high absorption rate, stays wet, and breaks up during the normal freeze thaw cycles. More to the point, the ballast fills the available roof area available to contain water. As a result during the storm or a large rain event the saturated roof flood over the cap flashing, down the fascia and the dye from the block is leached out and drips down the exterior wall indicating the black stain is a result of the roof overflow. The 4

5 absence of this condition at the rest of the walls below the third floor further point to the roof overflow as the cause. Drains are predominantly located at the roof to vertical wall intersections with some drains scattered in the open roof area. The roof drainage utilizes scuppers on the high roofs which drain to lower roofs and at the lower roof again scuppers drain to the main roof where roof drains pick up the water. III. ARCHITECTURAL INSPECTIONS AND WEATHER EVENTS DAMAGE A. Exterior Envelope Damage (1). Building Roofs and Roof Flashing The present condition of the roof was pre-existing prior to the storm events in August and September An inspection of the third floors of Divisions 1,2 and 3 found little interior water in the ceilings. Although the existing roof is marginally functional having a history of leaking, the most prevalent areas of damage occurred at the joint in the roof slab to vertical walls and in hair line cracks in the structural slabs themselves. The leaks here are manifest on the interior as efflorescent stains. This staining occurred on a regular basis before the storm but the amount of water in the storm intensified the water infusion through these cracks. To track the water paths from the roof the following illustrations taken from the construction drawings show the potential paths of water [Exhibit A]. The storms increased the pressure on these areas and all other weak points in the walls where water can migrate into the interior. There are many roof to wall flashings which on inspection lack the proper flashing techniques required for water seals.in addition the growth of moss at the wall roof junctions, drains, and pavers indicate accumulated standing water on the roof. ( PHOTOS: A-8,A-9,A-10,A-11,A-12,A-14,A-15) Given the condition of the roof, little actual damage of the interior due to the leaking roof was observed.. Most of the leaks are manifested as efflorescent stains. This staining has occurred on a regular basis before the storm but the amount of water in the storm intensified the water infusion through these cracks. (2). Roof Drains and Through Roof Piping Roof drains seem to be minimal and in poor condition. A few are located in the roof field but most are located at the junction of the vertical walls and the roof The roof is essentially flat. The condition of the existing roof drains, the overall lack of drains throughout the roof, lack of positive roof slopes, the inappropriate location of drains at walls, and the possible under sizing of the original drains all would reduce the ability of getting the water off the roof. (PHOTOS: A-20,A- 21,A-23,A-24,A-30,A-31,A-32,A-35) 5

6 There are numerous roof penetrations in the roof by drains, PVC vent piping, and electrical conduit that are not properly flashed by industry standards and will allow water to penetrate through the roof.(photos: A-32,A-33) (3). Walls Water intrusion into the interior from the roof occurs at the wall to roof slab intersection and at the hairline cracks in the structural slab.the walls themselves are in reasonable condition and only exhibit water and ballast dye stains at the third floor where the roof has overflowed.( PHOTOS: A-20,A-21,A-24,A-39) The attached illustrations taken from the actual construction documents and describe the potential paths of water into the building from the roof and walls Illustration 1. The lack of a cast in drip at the concrete fascia bottom or extension of the roof fascia over the wall below allows the water to travel down the fascia and migrate horizontally into the cavity wall. Wind and capillary action and horizontal winds serve as an enhanced water delivery system to the interior ( PHOTOS: A-10,A-11,A-18) Illustration 2. The poor installation and probable product failure of plastic flashing in the cavity wall allows the water to travel down the cavity and continue to the termination of the wall at the horizontal concrete slab. The water can then migrate horizontally and into the interior of the building( PHOTOS: A-19,A-20,A- 28,A29,A-30) Illustration 3. This detail is typical of the exposed rough formed concrete wall above the horizontal floor and roof slabs appearing throughout the facility. Although there is no cavity the wall has metal flashing. The flaw in this installation is that there is no horizontal water infusion protection from the roof in case of failure. Typically a continuous vertical water Bar is cast in the horizontal slab at the horizontal/vertical intersection (cold joint) blocking any water from entering the interior.(photos: A-12,A-25,A-26,A-27,A-28,A-29) The exterior walls are in good condition with little leaking through the wall to the interior, occurring at the wall to floor intersection. ( A-20) The wall staining is most apparent at the third floor walls below the roof. Here due to the incapacity of the roof to store water and the very low coping height at the roof edge the water overflows carrying the dye from the ballast paver down the face of the wall.(photo: A-39) Where the wall is protected by overhangs very little water and staining is observed ( PHOTOS: A-39,A-40) (4) Law Library and Adjacent Areas Evidence of leaking occurred in the Law Library and adjacent areas. The existing drawings indicate a mechanical equipment room on the roof above and one of 6

7 the exterior Mechanical Room walls crosses the area where the leaks occur. The deterioration of the wall /floor support beam traversing the space indicates either flooding in the mechanical room floor proper ( no water at the time of inspection) or in the vertical exterior wall above the beam at the roof. (PHOTO: A-13) (5). Electrical Switch Gear Vacant Transformer Room and Adjacent corridor Division 1 At the exterior stair landing between Unit 1 and 2 ( refer to the second floor plan Division 1) stairs between column lines 10,11, D, and E (PHOTO: A-2) a graded earth berm is sloped toward the paved landing. Water was standing on the pebble finished stair landing during the inspection. The construction joint between the landing slabs requires maintenance and there are water stains in this area from past water ponding. Under this area in the basement is the Electrical Switch Gear Room and adjacent former oil based transformer room now vacant. Water is entering the Electrical Switch Gear Room at the top of the wall (A-7). Although the landing is under cover at a higher level, the probable cause is the water getting below the landing slab and runoff from the adjacent berm which directs the water to the stair landing. In addition the leaks are present in the adjacent corridor ceiling, wall, and floor to the Switch Gear room (PHOTOS: A-4,A-5,A-6). It is not known how or to what extent the Switch Gear ceiling slab and walls were water proofed during construction or the method of doing it. (6). Internal Mechanical Piping Trenches, Valve Pits, and Sump Pump Pits Internally in the first floor of Division 3 (south side) there is a mechanical trench running along column line M between columns 2 to 7 that has water in it. The source could be external water from the grading or pipe leakage. Water bills were requested from the Country to see if possible pipe leaks could be inferred from the bills.(photo: A-1) On the north side of Division 3 further mechanical piping trenches are located started at column 7P and running east internally at the building perimeter to Column line 2 and turning south to column line O. These pits contained water and either there is leakage from the piping or ground water is seeping into the trenches. No details are available to determine if any of the trenches were water proofed during initial construction or if any foundation drainage was installed at the perimeter walls. In addition there are additional sump pits and access doors in the First Floor of Division 3 at the raised floor area in the Jury Selection Room at column lines 2 and 3 at Column line N, as well as, in the vicinity of the raised floor area at column P5. There was some water in these pits and it was not clear if these pits connect or what system they are a part of. IV CONCLUSIONS 7

8 The rain events of August and September 2011 overwhelmed an existing deteriorated roofing and insufficient pump systems. Below grade support spaces and pipe trenches were flooded and required pumping from an overwhelmed sump pump system. The deteriorated condition of the roof, drainage, and penetrations prior to the flood is the root cause of the subsequent problems in the interior space primarily on the third floor of all divisions.. The existing building ground floor elevations at grade and volume of water during the flood from the adjacent creek caused the flooding of the below grade service spaces. The stair landing above the of the Electrical Switch Gear Room, vacant transformer room, and adjacent corridors allowed water to seep into these spaces. Within the courtyard area the grading which is partially sloped to the building may be a contributing factor to the pipe trench flooding in the First Floor of Unit 3. Sloped grades to the north side of Unit 1 may contribute to the Electrical Switch Gear Room Flooding. The present roof depends on a single layer of roofing to protect the interior spaces and the system has failed to do that. Protection from water penetration should be provided at the last point of entry to the interior namely at the structural roof slab and vertical walls regardless of the type and composition of the final roof. The existing roof should be replaced and the amount and location of roof drains should be reconsidered. Suspected deteriorated cavity wall flashing, as well as, the apparent lack of weep holes potentially allow water in the wall to gather at the wall s base and infiltrate the building. Only one area of direct wall leaking on the floor at the interior was found.(photo: A-19). The walls are in good condition. If additional leaks on the floor develop, the walls should repaired at that actual leak location only. The vertical walls where not exposed to the third floor roof flooding showed little water absorption or staining and do not need to be replaced. (PHOTOS: A-16,A-17,A-38) Prevention of water Infusion to the lower service spaces should start with the removal of the existing stair landing slab, the area examined, and reconstructed as a watertight envelope forming the electrical Switch Gear room and adjacent spaces ceiling. The pipe trenches must have a reliable pumping system and a methods to deal with large water infiltrations as a result of protracted rain if the existing trenches and piping are to remain viable. The window systems weathered the storms in reasonable fashion with only a few water intrusion locations generally at the window heads. All the calking in the windows should be replaced. 8

9 Appendix A Photographs 9

10 (A-1) GROUND SLOPES TOWARD BUILDING AND AREA DRAIN. MECHANICAL PIPING TRENCH BEHIND WALL CONTAINS WATER. THE AREA DRAIN IS QUITE SMALL FOR THE AREA DRAINED AND SOME PONDING WAS DETECTED. (A-2) GROUND TO THE RIGHT OF THE STAIRS SLOPES TOWARD THE STAIR LANDING. STAIRS EXPOSED TO WEATHER AND CHANNELS WATER TO LANDING. UNDER LANDING IS THE ELECTRICAL SWITCH GEAR ROOM, THE FORMER TRANSFORMER VAULT, AND ADJACENT CORIDOR. WATER WAS STANDING ON THE LANDING AT THE LAST SITE VISIT. 10

11 (A-3) IN THE ELECTRCIAL SWITCH GEAR ROOM THE RESULTS OF THE WATER INTRUSION FROM THE SURFACE ABOVE ARE OBVIOUS. NOTE THE ORANGE HOSE IS DRAINING A SUMP PUMP THROUGHT THE TRANSFORMER VAULT (A-4) WATER HAS LEACHED DOWN THE WALL CORRODING METAL PANEL COVERS AND CONDUIT. MOST OF THE FLOOR IS COVERED WITH WATER DURING THE LAST SITE VISIT. THIS PHOTO WAS AFTER THE SECOND VISIT IT DURING A RAIN EVENT. 11

12 (A-5) THE CORRIDOR OUTSIDE THE SWITCH GEAR ROOM HAS WATER FROM THE SLAB UNDER THE STAIR LANDING ABOVE. SEE PHOTOGRAPH (A-4) (A-6) CORRIDOR CEILING AT THE LEAKING ROOF SLAB. 12

13 (A-7) THE ASSESMENT TEAM SUSPECTS THAT THE WATERPROOFING ON THE SWITCH GEAR ROOM ROOF SLAB ABOVE IS EITHER NON EXISTANT OR COMPROMISED. ALSO THE CALK JOINT IN THE SLAB ABOVE MAY BE THE JOINT BETWEEN MULTIPLE ROOF SLABS AND REQUIRES MAINGTENANCE.. THE LACK OF DOCUMENTS PREVENTS A FIRM CONCLUSION ON THE INITIAL WATERPROOFING DETAILS OF THE ROOF SLAB. HOWEVER, THE LEAKS INTO THIS ROOM ARE LONG STANDING. B. EXISTING WALL FLASHING AT ROOF 13

14 (A-8) TYPICAL CONDITION OF LACK OF FLASHING CONTUNITY AND POOR MAINTANENCE (A-9) POOR TRANSITION TO WALL/COPING JUNCTION AND OPEN AREA TO INSIDE WALL BELOW 14

15 (A-10) POORLY MAINTENANED JOINT AT ROOF SLAB TO WALL. LACK OF THROUGH WALL FLASHING. (A-11) ATTEMPTS TO CALK THE OVERSIZED JOINT (PHOTO: A-10) JOINT WITH A PUTTY LIKE CALKING. NOTE WEATHER WEAR ON TOP OF FINS 15

16 (A-12) INADEQUATE WALL FLASHING AT THE LIGHT MONITORS AND ROOF FAILURE AS WELL AS ALLOWING WATER TO MIGRATE INTO THE INTERIOR AT THE ROOF SLAB. (A-13) SUPPORT BEAM FOR MECHANICAL ROOM WALL ON ROOF. WATER INFUSION FROM EITHER THE EXTERIOR WALL ABOVE OR FLOOR FLOODING HAS DETERIORATED THE CONCRETE BEAM AND LEAKED WATER INTO THE LAW LIBRARY CEILING BELOW. 16

17 (A-14) CONCRETE FASCIA AND CALKING DETERIORATION AND COMPROMISED REINFORCING REQUIRES EXTENSIVE REPAIR AND PROBABLLE WINDOW AND FRAME REPLACEMENT. (A-15) POOR FLASHING JUNCTION NSTALLATION 17

18 (A-16) THE EXISTING DOCUMENTS INDICATE CAVITY WALL FLASHING. AND WEEP HOLES TO ALLOW THE WATER TO DRAIN FROM THE WALL. FEW WEEP HOLES ARE APPARENT IN THE EXTERIOR WALLS. (A-17) WALLS PROTECTED BY OVERHANGS AND NOT EXPOSED TO VERTICAL RAINS AND THE EFFECT OF ROOF WATER OVERFLOW DO NOT EXHIBIT THE WATER AND DYE SATURATED PATTERNS. WIND DRIVEN RAINS HAVE LESS OF A WALL SATURATED PATTERN OR THE PATTERN IS NON EXISTANT. 18

19 (A-18) SOME WALLS HAVE PROPER FLASHING AT THE COPING AND BETWEEN THE COPING AND WALL; HOWEVER WATER OVERFLOW PATTERNS INDICATE COMPROMISED FLASHING AND WATER INFILTRATION AT THE STRUCTURAL ROOF SLAB. (A-19) THERE IS SOME EVIDENCE THAT THE LACK OF CAVITY WALL FLASHING AT THE SUPPORT SLABS CONTRIBUTES TO LEAKING WALLS AND INFILTRATION AT THE INTERIOR FLOOR LEVELS. 19

20 (A-20) ROOF COPING TOO LOW, JOINTS NOT FLASHED OR MAINTAINED AND ROOF CANNOT DRAIN (A-21) ROOF OVERFLOW AS A RESULT THE ROOF S INABILITY TO HOLD WATER AND ABSENSE OF PROPERLY LOCATED ROOF DRAINS. NOTE THE BALLASTS WHICH HAVE BEEN REMOVED TO ATTERMPT TO DRAIN THE ROOF AND BALLAST DEBRIE AND DYE WHICH HAS LEACHED FROM THE PAVERS. 20

21 (A-22) THIS FASCIA AND THE BALLAST STAINS ARE THE RESULT OF WATER STAINING AS PER PHOTOGRAPH (A-21) ABOVE (A-23) BALLAST DETERIORATION IS DUE TO THE POUROUS NATURE OF THE BALLAST, WATER SATUARATION AND FREEZE THAW CYCLES. THIS CONDITION IS THOROUGHOUT THE MAJORITY OF ROOF AREAS.. 21

22 (A-24) BALLAST REMOVED TO PROVIDE A WATER PATH TO THE DRAIN. NOTICE THE COPING TOP IN REFERENCE TO THE BALLAST. (A-25) ROOFING WATERPROOFING HAS FAILED AND WATER HAS PENETRATED INTO THE STRUCTURAL SLAB AND ENTERED THE BUILDING THROGH THE CONSTRCUTION JOINT BETWEEN THE HORIZONTAL SLAB AND VERTICAL WALL 22

23 ` (A-26) FAILED ROOF SYSTEM AND HAIRLINE CRACKS IN STRUCTURAL SLAB ALLOWED WATER TO PENETRATE THE CRACK IN THE SLAB. (A-27) FAILURE OF THE CAVITY WALL FLASHING AIDED BY THE SLAB TO WALL JOINT AT THE ROOF DECK AND BELOW THE BEAM ENABLED WATER TO ENTER THE INTERIOR 23

24 (A-28) SCOPE OF THIS WATER PENETRATION TO THE INTERIOR MASONRY AT THE CAVITY WALL AND WALL JOINT BELOW THE ROOF IS THROUGHOUT THE ENTIRE STAIR AT THIS LEVEL (A-29) ENLARGED DETAIL OF (D-11) ABOVE 24

25 (A-30) MOST ROOF DRAINS ARE LOCATED AT THE BASE OF THE VERTICAL WALLS (A-31) THE HIGHER ROOFS ARE DRAINED BY SCUPPERS ON THE TO THE NEXT LOWEST ROOF AND FINALLY TO THE MAIN ROOF WHERE THE WATER IS PICKED UP BY THE WALL DRAINS AT THE LOWEST ROOF. THE SCUPPERS EJECT THEIR WATER CLOSE TO THE WALLS AND NO SPLASH BLOCKS ON THE MAIN ROOF TO MIGATE THE FORCE OF THE WATER HITTING THE ROOF DECK ARE INSTALLED. NOTE THE SCUPPER ON THE LEFT SIDE OF THE PHOTO. AND ONE OF THE FEW ROOF DRAINS LOCATED IN THE MAIN ROOF AREA. 25

26 (A-32) (A-33 (A-32) (A-33) PENERTRATIONS THROUGH THE ROOF, DRAINS, EQUIPMENT, CONDUIT AND VENTS IMPROPERLY FLASHED SERVE AS WATER CONDUITS INTO THE INTERIOR OF THE BUILDING 26

27 (A-34) (A-35) (A-34 (A-35) AGAIN, PENERTRATIONS AND MODIFICATIONS TO THE EXISTING ROOF WHICH HAVE NOT BEEN PROPERLY FLASHED AND SEALED CONTRIBUTE TO THE WATER INTRUSION TO THE INTERIOR. THIS PARTICULAR CONDITION IS IN THE MECHANICAL EQUIPMENT ON THE ROOF OF UNIT 2 ABOVE ROOM 3210 RESULTING IN INTERIOR DAMAGE. (A-36,A-37) IN THIS CASE THROUGH AN INTERIOR CHASE CARRYING A LARGE PIPE TO THE MECHANICAL ROOM ON THE ROOF. 27

28 (A-35) (A-36) (A-37) (A-36) (A-37)EVIDENCE OF WATER PENETRATION AT A CHASE WALL WHICH CONTAINS MAJOR PIPING DIRECTLY TO THE HVAC UNITS ON THE ROOF AT 28

29 (A-38) (A-39) (A-38 (A-39) VERTICAL WALLS BELOW THE THIRD FLOOR ROOF FLOODING EXHIBIT LESS WATER ABSORPTION AND STAINING. 29

30 (A-40) WATER OVERFLOWING ON THE WALLS IS MOST PREVLANT AT THE THIRD FLOOR 30