Subject: Amphitheater School District Reroofing Projects Amphi High School, Building 900 Roof Evaluation SCI Project Number:

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1 27 June 2016 Mr. Shane Chism, AIA Breckenridge Group 4625 E. Fort Lowell Road Tucson, Arizona Subject: Amphitheater School District Reroofing Projects Amphi High School, Building 900 Roof Evaluation SCI Project Number: Dear Mr. Chism: In accordance with your request, we have completed a structural review of the Amphi High School Building 900 roof. The review is performed as part of the Amphitheater School District Reroofing Projects. Please find attached our report presenting the results of our assessment. Also attached as appendices are photographs taken during the visual inspection and existing structural details pertinent to items for review or discussion. Please note that the inspection of an existing building requires that certain assumptions be made regarding existing conditions and some of these assumptions may not be verifiable without expending additional sums of money, or destroying otherwise adequate or serviceable portions of the building. This report is based on visual observations and there is no claim, either stated or implied, that all conditions were observed. I hope this report is responsive to your needs. Please do not hesitate to call if you have any questions. Sincerely, Structural Concepts Inc., Jennifer M. McMahon, P. E., S.E., SECB Structural Engineer

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4 SCI Project Number Amphi High School Building 900 Roof Evaluation Page INTRODUCTION Structural Concepts was retained by your office to perform a structural review of the existing roof of the 900 Building at Amphitheater High School in Tucson, Arizona. On 26 May 2016, Jennifer M. McMahon, SE, was accompanied by Shane Chism, AIA, of Breckenridge Group, Pat Sledge of Amphitheater School District, and Ken Ramirez of Amphitheater School District. This review consisted of visual observation only, made solely to render an opinion regarding the structural integrity of the roof. Neither the review nor this report is intended to cover mechanical, electrical, or architectural features. This report presents the results of our study. The existing building is an approximately 7,500 square foot auto shop and classroom facility of the following construction: Date of original construction 1982 Single story building with mean roof height of approximately 11-feet over the classrooms and offices and a mean roof height of approximately 16-feet over the auto shop. Roof framing members framing members are noted to be wide-flange beams spanning in the north-south direction. Framing members at the high roof of the auto shop are exposed at the overhangs and were visually verified to be wide-flange members on the north side. The roof over the auto shop slopes slightly to the north, while the low roof slopes north and south away from the ridge at the approximate centerline of the building. Roof deck as noted in the available drawings, the main building roof deck is 1-1/2-inch deep, 22-guage metal roof deck. It was not determined if the deck was galvanized or painted during review of the documents and visual observations. A mechanical and storage room on the east side of the building was visually verified to have a cast-in-place concrete roof. Bearing walls, columns and piers roof framing members bear on the exterior walls and piers at the north and south sides, and bear on columns or bearing walls at the approximate centerline of the building. Bearing walls are double-wythe reinforced brick. Columns are tube-shape structural steel, and piers are reinforced brick masonry. Foundation and slab-on-grade foundations were not observable during our site visit. Documents indicate bearing walls and columns are founded on shallow spread footings, with concrete stem walls where required. The interior slabs are typically a 6-inch thick slab-on-grade. The purpose of this report is to perform a visual review of the roof, review available drawings of the existing building, evaluate the existing framing for any proposed roof top modifications, and make general recommendations for required and recommended repairs prior to reroofing.

5 SCI Project Number Amphi High School Building 900 Roof Evaluation Page INVESTIGATION 2.1 Document Review Existing drawings titled, New Diesel Auto Shop, Amphitheater High School, by GCA Architects, and sealed on 26 January 1982, were reviewed during the course of our investigation. Of particular assistance to our review are drawing numbers A-3 through A-5 and S-1 through S Visual Site Observation Visual observations were performed from the topside of the roof and from grade at the exterior and interior of the building. Interior spaces were largely obstructed from view by drop ceiling panels or insulation. The following observations were made: 1. Flashing and metal deck deterioration was observed in two locations on the perimeter of the low roof. Photos 7 and 8 identify deterioration on the south edge near the southwest corner and deterioration on the north edge, respectively. From the ground, it was not visible if structural steel edge members and overhang supports were also deteriorated. 2. The interface between the brick wall and the cast-in-place concrete roof at the southeast corner of the mechanical room indicates there is or may have been a roof leak. There are signs of rust likely from a structural steel

6 SCI Project Number Amphi High School Building 900 Roof Evaluation Page 3 angle as shown in detail 11/S-4. (Refer to photo 11.) No other areas of rust or cracks were observed in the roof slab. 3. The flashing and the wood blocking at the east edge of the mechanical and storage rooms is deteriorated, and at least one bolted connection between the wood blocking and the slab has failed. (Refer to photos 9 and 10.) 4. The Amphi representatives indicated the roof deck immediately south of the roof-top-unit at the west end of the low roof failed under foot traffic loads and was patched with plywood in the past. Deterioration is thought to be caused by persistent condensate leaks. The plywood patch is approximately 4-feet square. The surrounding area was perceptively soft when manipulated. (Refer to photos 12 and 14.) 5. Evidence of ponding was observed at the north side overhang of the high roof. (Refer to photos 15, 16, and 17.) The roofing material appears to be depressed and deteriorating around the northwest corner and approximately 28-feet to the east. Flashing has either been removed or deteriorated significantly. 6. The underside of this overhang is accessible from the low roof. The roof edge members are channels welded or bolted to cantilevered roof framing members, with angles welded to the inside of the channels for edge support of the metal deck. (See detail 10/S-3.) The steel members and metal deck immediately adjacent to the area of ponding are highly deteriorated, with signs of extensive corrosion and delamination. Typical conditions are represented in photos 18 and 19. Edge members and metal deck east of the ponding area do not appear to be highly deteriorated. 7. It is proposed by Amphi to remove the western roof-top-unit on the high roof. Based on observations from the interior, it appears the existing opening matches detail 14/S-4 of the existing documents. 3.0 CONCLUSIONS/DISCUSSION Based on our site review, the following conclusions are made: 1. Outside of deterioration identified in our visual site observations, no other structural concerns were identified at the roof framing and metal roof deck. The roof structure appears to be generally in good condition. 2. The deterioration of the structural steel and deck at the northwest corner of the high roof is a structural problem. Steel members likely have lost significant section property due to delamination and corrosion, and deck has deteriorated

7 SCI Project Number Amphi High School Building 900 Roof Evaluation Page 4 beyond a point of repair. Replacement of these components is encouraged. The extent of replacement will need to be verified in the field. 3. Areas east of the deterioration identified immediately above will need to be verified in field. Visual observations indicate severe deterioration is limited to the western 28-feet of the high roof, however it is probable deterioration has occurred under the flashing and roofing materials and was not visible during our review. 4. The deterioration of the metal roof deck identified at the perimeter of the low roof is a structural concern, and the deck should be replaced. At this time, the extent of deteriorated deck is unknown. In addition, it was not apparent if structural steel support angles or tees have experienced any deterioration. 5. Based on previous repairs and existing areas of soft roofing around the western roof-top-unit on the low roof, it is probable a large portion of metal roof deck is deteriorated. Extent of deck damage will need to be verified in the field after roofing materials are removed, and the damaged deck should be replaced. It is probable roof framing members below the damaged deck were also exposed to the leak, and will need to be field verified. 6. The deterioration of the flashing and wood blocking, as well as the apparent leaking, at the mechanical room roof does not appear to be a structural problem at this time. The conditions could become a structural problem if left unrepaired. 4.0 RECOMMENDATIONS The following recommendations to be performed during the reroofing project are offered: 1. Following the removal of existing roofing material, the contractor shall perform a general condition site survey. Contact Architect with all unforeseen conditions. 2. At the northwest corner of the high roof, remove and replace like-in-kind structural steel members and deck that is deteriorated and delaminating. Extent of replacement required shall be verified prior to commencing. Anticipate the following: a. Remove and replace approximately 28-feet of steel channel and edge angle assembly, C12x20.7 with L3x3x1/4. Refer to existing document details 10/S-3, 1/S-4, and 2/S-4. b. Remove and replace approximately 90 square-feet of metal roof deck. Metal roof deck shall be as noted in the project specifications. Deck shall be placed in a three span condition. i. Attachment to primary support members: 30/4 or 36/4 pattern, welds shall have effective fusion area of at least ½-inch in diameter, or approved mechanical fastener.

8 SCI Project Number Amphi High School Building 900 Roof Evaluation Page 5 ii. Sidelaps: 18 on center maximum, 1-1/2 long top seam weld, button punch, #10 TEK screw, or approved alternative. iii. Metal roof deck is considered exposed at the overhang and shall be meet G90 coating requirements. c. Provide roofing materials and flashing per Architectural details and specification. 3. At areas of deteriorated roof deck with structural steel supports showing rust, but no delamination: a. Clean structural steel supports of rust to white metal using mechanical wire brush or sand blasting. b. Replace metal roof deck like-in-kind. Follow general guidelines as defined in recommendations 4.2.b.i through 4.2.b.iii. 4. At areas of deteriorated roof deck without structural steel damage, remove and replace metal roof deck like-in-kind. Follow general guidelines as defined in recommendations 4.2.b.i through 4.2.b.iii. 5. Around existing roof-top-unit as noted in visual observation 2.2.4, replace metal roof deck like-in-kind. Single span conditions may be utilized. Provide deck thickness as required by project specifications for single span condition. Attach deck to primary support members with 30/7 or 36/7 attachment pattern and sidelaps at 18 on center maximum. See 4.2.b.i through 4.2.b.iii for allowable attachment types. 6. As identified in visual observation 2.2.7, the existing opening remaining after the removal of the existing roof-top-unit shall be infilled following guidelines noted in recommendation Flashing and blocking at the mechanical room concrete roof, identified in visual observation 2.2.3, shall be repaired according to Architectural requirements.

9 Photographs Page A-1 Building Amphi High School - Building North Elevation

10 Photographs Page A-2 3 West Elevation 4 South Elevation of roof line, west end

11 Photographs Page A-3 5 South roof line above shop garage 6 South roof line, east end above shop garage

12 Photographs Page A-4 7 Close-up of south roof line, approx. 10 from west corner 8 Close-up north side overhang, approx. 30 from east corner

13 Photographs Page A-5 9 Close-up east roof line at north end of storage and mechanical rooms 10 Close-up of east roof line at south end of mechanical room

14 Photographs Page A-6 11 Southeast corner of mechanical room, concrete roof deck and brick wall shows signs of previous leaking issues 12 Low roof from northwest corner looking southeast

15 Photographs Page A-7 13 Low roof from northwest corner looking east 14 Roof south of roof top unit previously repaired with plywood; roof deck around south and east sides of unit was perceptively soft and likely deteriorated.

16 Photographs Page A-8 15 Northwest corner of high roof looking east; low end of slope at evidence of ponding 16 Northwest corner of high roof looking south

17 Photographs Page A-9 17 North roof line of high roof toward the east; close-up of deterioration of roofing materials and corrosion of steel members 18 North overhang of high roof, close-up of typical bolted connection of fascia member to roof framing; significant corrosion of connection, channel, angle, and metal roof deck

18 Photographs Page A North overhang of high roof, close-up of typical welded connection of fascia member to roof framing; significant corrosion of connection, channel, angle, and metal roof deck 20 High roof from southwest corner of high roof looking north

19 Photographs Page A High roof from southwest corner of high roof looking northeast; RTU in foreground will expected to be removed and will require roof deck infill. 22 Underside of roof framing from interior of building within the shop. Insulation obstructed view of underside of deck

20 Photographs Page A Interior of northwest classroom; signs of water leaks are visible in the drop down ceiling, west wall, and cork board on west wall

21 Reference Details Page B-1 The following details are referenced from Structural Drawing sheets S-2, S-3, and S-4 of the New Diesel Auto Shop, Amphitheather High School, by GCA Architects dated January 1982:

22 Reference Details Page B-2

23 Reference Details Page B-3