New York State Capitol Building: Replace Roof, Center Courtyard, Main Floor

Title: New York State Capitol Building: Replace Roof, Center Courtyard, Main Floor

Award Category: Building Enclosure

Project Address/Location

State St. and, Washington Ave

Albany, New York 12224
United States

Submitted By: James Trevvett

Company Info

Bell & Spina, Architects-Planners, PC

215 Wyoming Street

Syracuse, New York 13204
United States

315.488.0377

[email protected]

Project Description and Background: The New York State Capitol, built between 1867 and 1899 is listed on the National Register of Historic Places and features a central open-air courtyard space approximately 125’ x 80’ in size. The courtyard contains a one-story copper clad central passageway, named the Hawk Street Passage with an adjoining restaurant space. The remaining courtyard space is the roof of the basement switchgear and mechanical equipment located directly below. Persistent leaks into the basement below the Courtyard along with deterioration of the Hawk Street Passage copper work prompted the restoration project. The Architectural firm was retained to restore the courtyard waterproofing and copper cladding and to reimagine the space, with public access. The project included roofing removal and replacement of the Courtyard. Malden Bluestone pavers were incorporated in the paver design which was the material originally specified for this courtyard space. The paver pattern was inspired by existing stone layouts found within the Capitol building. Large limestone planters with zinc-tin coated copper caps were installed to enhance the courtyard visually while concealing ventilation components. All original copper was removed and replaced, including flat and standing seam roofs, wall cladding, downspouts, and intricate ornate detail work. As a historical restoration project, the copper was replaced to match the original profiles while managing to incorporate thermal insulation improvements. The goal was to replicate the original copper cladding as closely as possible while being consistent with the restoration principles provided by the Department of the Interior Secretary Standards for Preservation. Previously infilled window openings within the passage were opened, as well as doors leading to the area. These windows provide visibility to the Courtyard that did not exist for decades. The Courtyard space was transformed from a utilitarian space into an occupiable area covered with pavers, planters, and vegetation as was originally intended.

Scope: • Bell & Spina Architects was retained by NYS Office of General Services based on the years of experience in the design of building enclosure, historic restoration, and producing detailed technical construction documents for publicly bid design projects. The project was staffed by iiBEC members and RRO’s. • The project scope included restoring the central courtyard of the NYS Capitol in Albany NY and the waterproofing systems, copper wall and roof panels, windows, granite facades and the interior finishes of the Hawk Street Passage. The primary goal of the project was to first waterproof the courtyard to protect the building infrastructure in the basement and provide for flashing and insulation improvements to the building enclosure without changing the historic appearance. This scope of work also created an opportunity to restore the ornamental copper wall and roof panel systems on the Hawk Street Passage, reimagine the interior Hawk Street passageway space and create a connection to a newly created outdoor courtyard space as was originally intended in the 1865 Thomas Fuller Masterplan. • A scoping report was developed by the Bell & Spina Architects to consider the contributing buildings historical features, condition of the courtyard exterior walls and roofs, related mechanical plumbing and electrical equipment, and recommended a scope of work, proposed options for consideration and develop construction cost estimates. The team developed project phasing and sequencing documents to accommodate the legislative sessions and incorporated quality assurance requirements for installer qualifications and full scale mockups of the copper wall cladding and roof assemblies. • An extensive investigation was undertaken in the study phase to verify the existing conditions. Test probes of the courtyard decking revealed over 14” of concrete, asphalt and macadam layers built up over the historic compressive groin vault arches in the basement space. The original ornamental copper paneling was removed to understand the wall construction and document the panel profiles. As a precursor to the project, a separate project was develop to stabilize and shore existing steampiping conduit, plumbing and duct work in the basement during he demolition operations. • Multiple waterproofing design options were developed and required incorporating roof insulatioin, mechanical ventilation improvements of the basement mechanical spaces, roof drainage upgrades while providing for a stable courtyard substrate suitable for a new paver system and capable of supporting future scaffolding for the building facades. The copper restoration work included complete replacement and replicaton with insulation upgrades and inclusion of new air barrier and vapor permeable weather resistive barriers. Condensation and dewpoint studies were undertaken to confirm the appropriate material makeup.

Solution: • The removal operations required complete removal of the various strata of overburden down to the brck vaults, roughly 13 to 14” thick and over 700,000lbs of material. A new concrete toppng slab was poured and a torch grade vapor retarder membrane installed. • The contract documents included specific criteria for loading and stockpiling of materials on the brick vaults to ensure that the vaults remain evenly loaded and true compressive arches. Real-time movement strain gauges were installed during construction to monitor the brick vaults during the demolition operations. • A lightweight low density insulating concrete base, approximately 13” at the high point was originally specified for the courtyard spaces based on the Siplast NVS system. A series of original cast-iron skylights were present at he oculus of each brick vault crossing and other obstructions found on the deck during the removals. However, the lightweight insulating concrete system fully encapsulated those irregular surfaces and allowed the installer to warp the top of lightweight concrete to the drains and create positive drainage. The original intent with incorporating a lightweight insulating concrete roofing system was ultimately achieved. A modified bitumen base ply and continuous liquid resin low odor cap was installed throughout the courtyard and tested via low voltage leak detection. • After extensive wood framing repairs were made to the Hawk Street Passage, the exterior walls and roof decking were clad with fire retardant insulated nailboard sheathing and 3” of interior side 2lb spray foam insulation. The exterior sheathing is wrapped in a vapor permeable (10perm +) WRB and padded with cedar 1x backing boards for the exterior ornamental copper metal panels. • Extensive technical details and installer qualification requirements were developed for the fabrication of the custom ornamental copper architectural wall panels, standing seam and flat-seam copper panels cladding the Hawk Street Passage and adjoining restaurant. Full scale copper mockups were built and reworked numerous times to ensure proper detailing and faithfulness to the original details. • The priority goal was met with the integration of the new courtyard roofing system with high-performance lightweight concrete fill insulation and multi-ply waterproofing system below a new courtyard paver surface without changing the original historic nature of the building. The project restored the courtyard to usable occupied space, including new copper clad wood doors and windows, replacement of the interior corridor finishes, lighting, fire sprinkler and heating systems. The courtytard space included integration of basement ventilation equipment with new planter beds and seating spaces. Restoration of the historic windows in the corridor provided an important visual connection to the courtyard and an opportunity to re-introduce natural light. Seating, architectural lighting, and plantings were used to provide respite, scale and to soften the space, encouraging gathering.

Value: • Bell & Spina Architects was engaged throughout the project, working with the contractor and assisting the team in resolving open issues throughout the project, and conducting site visits including 2nd and 3rd shift work visits. • The design team focused on the detailing of the building enclosure systems and insulation improvements to conceal the continuous thermal, air and vapor control layers behind the historic ornamental copper wall and roof metal panels without changing the appearance of the historic building. • The courtyard and Hawk Street Passage have been transformed into a visual focal point in the capitol building and represents a commitment to restoring the historic heritage of the original design intent with consideration for future needs and opportunities in the courtyard. • The architectural team worked with the sheet metal mechanics to design and detail as many soldered and locked copper details as possible to minimize any exposed fasteners and arrange copper wall cladding joints to minimize visual impact and distortion of the wall cladding. Stamped copper egg & dart moldings and scroll work was used to match the original details. And ornamental rosettes were instead installed with blind fasteners in lieu of soldering to avoid unsightly field soldering. A full scale mockup of one typical window bay was fabricated for review and refinement of the copper paneling and to set the standard of acceptable workmanship. Sheetmetal mechanics were required to demonstrate experience and soldering skills. • The selection of materials and quality assurance testing and inspection process ensures that the roofing and wall panel systems will last a long time, anticipated to be a 75 year plus system with minimal maintenance. Granite will last forever.

Project Images

Documents

Videos