Report Dallas Township Elementary School Dallas, Pennsylvania (JBCI Project No. 144911) 1655 Suburban Station Building 1617 John F. Kennedy Boulevard Philadelphia PA 19103 215 665 0497 5 Sandwood Drive Marlton NJ 08053 215 852 1320
TABLE OF CONTENTS TITLE PAGE NO. INTRODUCTION 1 DESCRIPTION/HISTORY 2 SUMMARY OF FINDINGS 5 STRUCTURAL ANALYSIS 6 CONCLUSIONS/RECOMMENDATIONS 7 APPENDIX First Floor Plan Photographs No. 1-26
STRUCTURAL ASSESSMENT DALLAS ELEMENTARY SCHOOL DALLAS, PA INTRODUCTION In accordance with our proposal dated December 24, 2014, we submit herewith our Structural Assessment Report of the Dallas Elementary School (The School ) for the Dallas School District. The purpose of this report is to provide an assessment of the main structural components throughout the School to allow the Dallas School Board to make prudent decisions regarding the School s future. Our condition survey was done on December 29, 2014 and consisted of reviewing available drawings, performing structural calculations and visual observations of representative areas within the School. We focused on the main roof framing and the brick exterior façade. Our assessment did not include a full structural analysis. We did, however, analyze several key roof framing members to gain a better understanding of the structural capacity. We were assisted by the School maintenance staff to remove sections of the existing ceiling tile. We wish to acknowledge their helpful assistance. NOTE: CONCLUSIONS REACHED IN THIS REPORT ARE BASED ON OUR VISUAL SURVEYS, LIMITED EXPLORATIONS AND SELECTIVE TESTING. WHILE WE ENDEAVORED TO DOCUMENT ALL ITEMS OF CONCERN AND DISTRESS BY APPLYING OUR ENGINEERING EXPERIENCE, PRUDENT JUDGMENT AND REASONABLE CARE, IT MUST BE UNDERSTOOD THAT HIDDEN CONDITIONS AND/OR UNAVAILABLE DOCUMENTS MAY EXIST WHICH MAY IMPACT OUR REPORT.
DESCRIPTION/HISTORY The current School was built in three phases. The original section (1) built in 1972 was designed by Panelfab International Corp., Miami, FL. The housing shelter was converted to a school several years later. The first addition (2) was done in 1989 and designed by Smith, Miller & Associates, Wilkes Barre, PA. We believe it consisted of adding two classrooms to the north end, one room to the east end, a brick veneer to the original metal panel façade and the front entrance brick masonry columns. The latest addition (3) was designed by Quad 3 Architects, Wilkes Barre, PA in 1997 and included the current gymnasium, interior renovations and two large skylights in the center section. The current building layout with the denoted additions is illustrated in the aerial photo below: 3 2 1 2 Current Dallas Elementary School The roof configuration is a shallow 2/12 slope gable style with valleys at the intersection points. The roof drains to gutters and downspouts along the eave. The original roof construction consists of the following: Asphalt shingles over 4 thick, 2-0 wide insulated metal panels that span approximately 15-0 ± to W16 steel purlins. The purlins span 30-0 to W18 steel rafters. The rafters are supported by interior steel columns and the exterior load bearing honeycomb core wall panels. The roof cantilevers approximately 8-0 over the front, west entrance. Page 2
The roof framing uses a very economical cantilever type system. The upper insulated panels are supported by the lower cantilevered panels that create a visible vertical offset. In addition, the columns are slightly offset from the roof ridge line. The individual insulated panels are anchored together with a series of clips and cleats. We must note that the Panelfab International Corp. drawings are very detailed and appear very accurate. Vertical offset South side valley intersection Vertical offset During the 1987 renovation a 4 wide brick veneer was installed over the original exterior metal panels. The brick was supported by a bottom steel angle anchored to the first floor concrete slab. The front brick masonry piers were added to give the appearance they were supporting the roof. 1989 brick masonry piers Original metal panel facade 1989 brick veneer The 1989 and 1999 roof framing is a more conventional metal deck over open web steel joists and structural steel framing. Page 3
Circa 2010 a roof deflection was observed in the vicinity of Room 206. Further investigation found that a section of insulated metal panels vertically displaced relative to the adjacent panels. A stabilization plan was developed and supplemental steel beams were installed. As a precaution, approximately one year later additional wood rafters were installed to support the upper portion of the roof. Supplemental steel and wood blocking added Wood rafters added It was also reported that localized sections of the concrete slab-on-grade have settled in the vicinity of the original/1989 interface corridor. These areas have been repaired. Page 4
SUMMARY OF FINDINGS Our visual condition survey consisted of observing the in-situ conditions around the building perimeter and from accessible points within the interior. We observed the existing roof framing condition by removing acoustical ceiling tiles in the following classrooms (See Appendix for floor plan): 102 113 210 107 200 302 112 206 308 Our visual observations can be summarized as follows (see Photos No. 1 through 26): Roofing System The asphalt shingles on the main 1973 construction are in generally fair to good condition. Inconsistent roof flashing and construction at the north and south valleys. Evidence of flashing uplift and nail pull out on the south side valley Loss of asphalt adhesion along the eave, particularly along the north elevation. Gutters and downspouts in generally good condition; isolated gutter anchor/nailing failure. Evidence of uplift along the asphalt shingles, particularly close to the eave. Evidence of slight roof rolling above Room 200. Roofing over the 1989 and 1997 additions in generally good condition. Roof Framing The roof framing is in generally good condition. There is no evidence of metal panel displacement, shifting or corrosion. The ceiling hangers are still engaged into the underside of insulated roof panels. The vertical transition at the cantilevered roof panels is still performing as intended. There is an isolated cracked roof panel above the exterior wall in Room 200. Initial indications are the panel was damaged during the original installation. There is also a slight vertical offset along the longitudinal panel joint; there is no evidence of recent movement. The roof panel displacement occurs at the longitudinal joint adjacent to a cantilevered angle. There is no visible distress and we believe the vertical offset and angle were originally built that way. Slight vertical offset at panel joint Page 5
Exterior Brick Veneer Isolated open brick cracking at window heads along the front (west) elevation. Inconsistent brick veneer support angle orientation. No evidence of brick settlement, however. Large gaps (up to 1-1/2 ) around the window frame and brick veneer rough opening. A variety of sealant material used within these gaps. The sealant in general has outlived its useful life. Vertical sealant at the original/1989 interface has squeezed out indicating excessive thermal movement. The brick veneer within the 1997 addition is in generally good condition. All brick masonry piers along the front entrance exhibit rotation and displacement at the top, under the roof soffit. Many of the containment angles installed at the cantilevered ceiling are missing. Reportedly one brick masonry pier recently fell over during a high wind storm. It was subsequently rebuilt. Miscellaneous There was a significant difference in the classroom interior temperature throughout the School. We found many classrooms with heavy drafts and reportedly is difficult to maintain a constant temperature throughout the year. Evidence of heavy water intrusion within the bathroom between Classrooms 108 and 300. Also evidence of water intrusion along the exterior north wall of the 200 Classrooms. Reportedly during the extreme colder temperatures last year ice dams formed along the roof eave/gutters. Localized concrete sidewalk settlement along the front entrance, south side. STRUCTURAL ANALYSIS To better understand the original 1973 roof framing capacity we reviewed the original drawings and performed a basic structural analysis of several key members. We then compared our findings to the current code requirements. The current code states that the snow roof loading for the Dallas, PA area be case specific. This means the local code official ultimately determines the required snow loading design for this area. We spoke with Mr. Dave Williams of the Building Inspection Underwriters. He stated that the current design ground snow load is 40 psf. Several factors are then applied to this requirement to determine the design roof snow load of approximately 30 psf. This equates to a roof snow depth of approximately 1-3 to 1-6, depending on the density or wetness. The original Panelfab International Corp. drawings do not specifically state a design snow load. Based on our analysis of selective steel framing members we found the roof can safely support the current roof snow load of 30 psf. If the snow depth nears this level there is a high probability of visible deflection. It is important to note that we cannot verify the roof insulated panel capacity because that is manufacturer specific. Page 6
CONCLUSIONS/RECOMMENDATIONS Based on our visual observations, review of available drawings and professional experience, the School main roof and supporting structure is in overall good condition. There is no visible evidence of current movement or distress. The isolated roof repairs made in Room 206 have stabilized this framing. While there is some visible evidence of roof panel displacement and damage above Room 200, it is my opinion this occurred during the original installation. This is one area I do recommend monitoring for any future movement. The main framing within the two additions (1989 and 1997) is also in generally good condition. It is important to note the existing 2/12 roof slope is very shallow for an asphalt shingle roof. This slope makes the materials and more susceptible to premature deterioration. There are reportedly two areas of water intrusion. The water intrusion within the bathroom is due to failed roofing within the valley intersection above. The valley construction consists of difficult vertical transitions and intersections using conventional asphalt shingles and sheet metal. The water intrusion along the 200 series classrooms is due to failed roofing and flashing along the eave. This north elevation is subject to much colder temperatures that will lead to asphalt adhesive failure. Reportedly ice dams have formed in recent years. These conditions will lead to deterioration and water intrusion. In lieu of patches I recommend the following long term roofing/upgrades: 1. Replace the entire valley asphalt shingle and flashing material with a seamless material that is more suitable and durable to the difficult offsets and intersections along the shallow slope 2. Install a heat trace system along the roof eaves, particularly along the 200 level classrooms, north elevation. This will help prevent ice damming and water getting under the shingles. The brick veneer added in 1989 exhibits localized areas of distress and deferred maintenance. My immediate concern is the free-standing brick masonry piers along the front entrance. These piers were added to give the appearance of supporting the roof overhang. The piers however, are structurally independent of the roof structure and are not adequately braced at the top. We observed significant rotation and are in danger of falling over during high wind events, similar to what already occurred. I recommend either: 1) the piers are permanently removed; or 2) more sufficient bracing be installed at the top. Please note that the two masonry columns at the north end entrance are structural and must remain. 1989 brick masonry piers added and can be removed These brick masonry columns must remain Page 7
A potential source of hidden water intrusion is the open window perimeter joints. Depending on the construction sequence, I believe the windows were not sized properly to fit the original metal panel/brick opening or the brick was not built close enough to the frame. There have been a variety of caulking attempts made to seal the gap but these materials have long outlived their useful lives. I am concerned that water is now entering these gaps and collecting within the brick/metal panel interface. This brackish water may be undetectable and causing hidden damage. The windows are also generally not operable and inefficient. Based on my observations, analysis and brief discussions with School administrators, it is my professional opinion the decision to occupy the School for the foreseeable future should not be based on the structural framing conditions. I believe there are more influential factors, such as evaluating the mechanical heating and air conditioning systems, roofing, window operation and overall functionality that will impact the School Board decisions. I recommend the School Board consider an energy audit of the building envelope and mechanical systems to help evaluate the future options. If the School Board intends to utilize the School for the foreseeable future, I recommend the following maintenance repairs with an order of magnitude construction costs: Repair Items Cost ($) 1. Rake and seal around all classroom window perimeters. $ 25,000.00 This will require removing all existing material. 2. Repair the cracked areas above the window heads. $ 8,000.00 Install soft joints along the steel lintels. Sawcut to widen the vertical joint between Rooms 310 and 312. 3. Provide positive restraint at the top of the brick $ 6,000.00 masonry front piers. 4. Replace the valley roof construction with a seamless $ 25,000.00 material. 5. Rebuild the settled front sidewalk. $ 3,000.00 6. Install a roof heat trace system along the eaves. $ 20,000.00 7. Secure loose brick veneer support angles $ 2,000.00 8. Monitor the damaged roof panel above Room 200. $ N/C Total $ 89,000.00 Submitted by Allen Roth, P.E. Professional License No. 032848E AR:t enclosures Page 8