Delaney-Vogel School

Transcription

1 Wrentham Public Schools Delaney-Vogel School Schematic Design 1. INTRODUCTION Wrentham Public Schools contracted with Turowski2 Architecture, Inc. on November 11, 2015 to assess necessary roof repairs to arrive at a Schematic Design and Project Cost, with the goal of a Project Funding Agreement with the MSBA for the Delaney-Vogel Elementary School, and in accordance with the MSBA Accelerated Repair Program. Turowski2 developed a base scope of work and deduct alternates for consideration. Our recommendation is to include the work of the base repairs and alternates for a total estimated construction cost of $1,454,199. Please see section 4 of this narrative for specifics on the alternates and our recommendation. 2. PROJECT TEAM Client: Allan Cameron Superintendent Wrentham Public Schools Beth P. Gilbert Business Manager Glenn Gillespie Maintenance Supervisor Owner s Project Manager: Michael A. Delvecchio Project Manager P-Three Inc. Daniel Pallota Project Manager Architect: T2 Architecture Inc. Peter Turowski Principal John Ferreira Project Manager Structural Engineer: Balram S. Chamaria PE B+AC, LLC MEP Engineer: Ben Miller HVAC Engineer Garcia Galuska DeSousa Mike Phillips Electrical Engineer Walter Araujo Plumbing/FP Engineer Building Envelope: Building Envelope Technologies Cost Estimator: Miyakoda Consulting Lance E. Robson Norkio Hall Page 1

2 Hazardous Materials: CDW Consultants, Inc. Kathleen Campbell 3. EXISTING CONDITIONS ANALYSIS The areas of the building included in the scope of this project were constructed in 3 phases. Two sections at the extreme north and south of the building are not included in the scope. These include the oldest section of the building date unknown (north) and the newest section of the building designed 2001 and completed 2002 (south). The three sections in the project scope include: The original school building, designed in 1954 and completed in 1955; The first classroom addition, designed in 1962 and completed in 1963; A classroom and office addition, designed in 1996 and completed in An assessment of the existing conditions follows: Windows and Skylights There are no skylights in the project area. Skylights had previously been infilled. There is one bank of wood clerestory windows above the roof line at the south wall of the cafetorium. These windows are original and in poor condition. Clerestory windows at the west wall of the cafetorium were replaced with aluminum windows in a previous renovation and are in good condition. Roofs 1954: The 1954 school building consists of mostly flat roof with a sloped roof over the multi-purpose room. Originally tar and gravel, the flat areas were re-roofed with EPDM in various stages. Continued leaking led to removal of the skylights on the west corridor of the school. Sections of the roof where skylights were removed were patched and sealed. The flat roof areas include interior drains. However, the roof areas are not pitched or sloped properly which causes ponding to occur in several areas. Leakage continues to be reported in numerous locations which is supported by the staining of ceiling tiles within the building. Several roof drains exist on the flat roof areas, however several are missing covers and do not appear to be functioning properly. Tests cuts in this roof area revealed unreinforced EPDM membrane fully adhered over 3 polyisocyanurate insulation which is mechanically fastened to gypsum decking with large polymer screws. These screws include anti-back out toggles through the gypsum deck. While the insulation was not wet, there is evidence of discoloration from past presence of moisture, and minor dampness was observed in the gypsum deck. The roof is in poor condition. Page 2

3 The sloped area of roof above the cafetorium drains to an eave box gutter. The gutter originally drained to internal drains at the four corners of the cafetorium. This roof was re-roofed as part of the 1996/7 addition/renovation project. Fiberglass reinforced asphalt shingles with and 8 exposure were applied over a non-vented ¾ plywood decking on 3 rigid insulation on existing deck. The steel gutter was relined with copper and the southwestern most internal drain was sealed and abandoned. An external downspout was added to the side wall of the gutter in this location. The steel gutter is severely rusted in several locations. The gutter liner and roofing is in fair condition. 1963: The 1963 addition consists entirely of flat roof. This roof was re-roofed as part of the 1996 addition/renovation. This area of roof includes internal drains which appear to be functioning. There was no reporting of leaking in this area. Test cuts in this roof area revealed two conditions: Infilled skylight areas: unreinforced fire rated EPDM fully adhered over 1-5/8 polyisocyanurate insulation over polyethylene sheeting over ½ gypsum board over 1-1/2 galvanized steel deck. The insulation in this location was mechanically fastened. There was no moisture observed and membrane appeared well adhered. Remainder of roof: unreinforced fire rated EPDM fully adhered over 3 tapered polyisocyanurate insulation over polyethylene sheeting over original gypsum deck.. The insulation in this location was mechanically fastened. There was no moisture observed and membrane appeared well adhered. This section of roof is generally in good condition. 1996: The 1996 section consists mostly of sloped roof areas above classrooms and administrative spaces with a small section of flat roof at the center of the north-south spine of the addition. The roof deck in this area is ventilated below through a combination of soffit vents and ridge vents (ridge vents do not exist at the sloped to flat roof transition in the north-south spine of the addition). Building envelope insulation occurs at the ceiling level and consists of 9 fiberglass batts placed between bottom chords of wood trusses above gypsum panels secured to the bottom chord of trusses. A suspended acoustical ceiling conceals this area. The flat section is fully adhered EPDM membrane over 1 wood fiberboard over ¾ plywood deck. This roof area drains to the east and west edges to the lower sloped roof sections. This section of roof is generally in good condition. The sloped sections of roof in this addition are covered with fiberglass reinforced asphalt shingles applied over roofing felts on ¾ plywood deck. The shingles have an excessive 8 exposure, and exhibit cracking in several locations. Multiple leaks and ice damming are reported in this area of the roof, Page 3

4 primarily west of the flat roof section and concentrated at valleys. Heat tape had been previously added to valleys to reduce ice build-up. These conditions may be attributable to the lack of high ventilation in the north-south spine of the addition and/or heat loss across the insulation envelope. Deformities in the plywood decking were also observed in this area, including deflected deck areas, suspected to be caused by missing sheathing clips or inferior sheathing product. Popped nail heads were also observed, which are potential points for leaking. Other Building Envelope Areas Various flashing conditions are inferior or deteriorating on roof to rising wall conditions. Masonry walls below the cafeteria roof have areas of spalling brick and deteriorated mortar. Structural Assessment Based on visual observation and review of record drawings and details, the existing roof framing poses no major structural issues. It is recommended that the Prescriptive Compliance Method be followed to meet the Massachusetts State Building Code. Under this compliance method, no structural upgrades are anticipated; however, an allowance for unit pricing should be carried in the bid documents for replacement or repair of gypsum deck and wood roof deck that may be identified during construction. See attached Structural Roof Assessment be B+AC dated November 10, 2015 for recommended scope of work. Mechanical, Electrical and Plumbing Equipment Assessment Both flat and pitched roof areas contain varying rooftop equipment including exhaust fans, make-up air unit, condensers and gooseneck vents. The majority of rooftop equipment will need to be removed during the replacement, with the exception of some equipment with high enough roof curbs. Efforts should be made to clearly tag all equipment to ensure replacement in the same location. See attached HVAC Existing Conditions Systems Report prepared by Garcia-Galuska-Desousa dated November 9, 2015 for recommended scope of work. Several exhaust fans, rooftop units and condensing units are currently located on the roof. All equipment will need to be disconnected, removed and reinstalled as part of the replacement of the roof. See attached Electrical Existing Conditions Systems Report prepared by Garcia-Galuska-Desousa dated November 8, 2015 for recommended scope of work. The flat roof areas contain seven roof drains, some of which do not have protective domes, and no emergency scuppers or secondary drains. In general, the roof drains are in fair to poor condition and in need of replacement. Current vent terminals do not meet existing code for distance above roof and will Page 4

5 need to be extended as part of this project. See attached Plumbing Existing Conditions Systems Report prepared by Garcia-Galuska-Desousa dated November 9, 2015 for recommended scope of work. Hazmat Assessment No hazardous materials were encountered. See attached Hazardous Material Summary Report prepared by CDW Consultants, Inc., dated December, RECOMMENDED PREFERRED SOLUTIONS Windows and Skylights Replacement of a single bank of windows at the cafetorium clerestory is proposed. New windows will be thermally broken aluminum frame windows with thermal properties that meet or exceed the 2012 International Energy Conservation Code (IECC 2012) Deduct Alternate: Alternate #3 eliminates this scope of work. Roofs The Wrentham School District has requested the use of a fully adhered 60 mil reinforced PVC membrane for all flat roof sections of the building, with new insulation meeting the 2012 International Energy Conservation Code (2012 IECC) requirements, R-25. Wrentham is not a Stretch Code community, but even if it was, the stretch code references the 2009 IECC which would result in the same value for roof insulation. Asphalt shingle areas will be replaced with architectural fiberglass reinforced asphalt shingles to match the most recent 2002 addition. A self-adhered underlayment will be provided on the entire roof area. Existing roof decking and insulation will be retained in all sloped roof areas. Deduct Alternates: #1 eliminates re-roofing of flat section of the 1963 section of the building and includes new flashings and seam repair only. #2 eliminates re-roofing of the flat section of the 1996 section of the building and includes new flashing and seam repair only. Page 5

6 Other Building Envelope Work Masonry: Replacement of missing brick and repointing of masonry in limited areas at rising walls above lower roofs is included in the scope. Ventilation: Aluminum louvers are added in rising wall above lower roof at the 1996 addition to improve ventilation below roofing deck in this area of the building. Insulation: Blow in Cellulose insulation will be added above the existing fiberglass insulation a the ceiling of the 1996 addition to eliminate heat loss and prevent ice damming. Interior Work Interior work associated with window replacement, louver installation, and insulation installation. Structural There is no structural work required. Mechanical, Electrical and Plumbing Existing roof mechanical curbs and vents shall be extended as needed to ensure a minimum of 18 above proposed roof height. Existing electrical equipment shall be disconnected, removed and reconnected and all wiring shall be reused. Existing roof drains are to be replaced. See attached HVAC/Electrical/Plumbing Existing Conditions Systems Reports and drawings prepared by Garcia Galuska DeSousa indicating required scope of work, dated November 9, Hazmat There is not hazardous material abatement associated with the work. 5. MEETING the SUSTAINABILITY REQUIREMENTS for the ACCELERATED REPAIR PROGRAM MSBA s Accelerated Repair Program uses the MA Stretch Energy Code (780 CMR Appendix 120 AA) as a basis for repair projects, including the replacement of roofs and windows. Although the standard "nonstretch" energy provisions of the code have been based on the 2012 International Energy Conservation Page 6

7 Code (IECC 2012) since July 1, 2014, the stretch code continues to be based on amendments to the 2009 International Energy Conservation code (IECC 2009) until such a time as the stretch code is updated. The following chart shows the requirements based on the current non-stretch code (IECC 2012) and the stretch code. All of the products and assemblies listed on the drawings and in the Outline Specifications comply with the most stringent minimum requirements. Criteria Stretch Code 2012 IECC Proposed Roofs Above Deck Insulation R-24 ci R25 ci R-25 ci Fenestration Metal framing All other U-factor U-0.44 U-0.38/0.40* U-20 *first value is fixed units, second is operable. Page 7