Pirnie Upper Envelope Project – Alexander Pirnie Federal Building

Replace approximately 28,500 sf of existing roofing systems at the Alexander Pirnie Federal Building (161’ x 166’) will be replaced with new roofing systems at Alexander Pirnie Federal Building. The existing 2” thick wood planking which is located beneath the mansard roofing system- will be replaced with new 2” thick wood planking which has field fabricated R-30 insulated panels installed on top of the new planking. The Yankee gutters will be replaced in their entirety with similar materials; and the existing roof drains and roof conductors located above the attic floor will be replaced in their entirety with new materials. The existing slate roofing materials which are installed on the sloped portion of the mansard roof will be replaced with synthetic slate materials and a new TPO roof membrane will be installed on the flat portion of the mansard roof. The ACM flashing materials which are installed at the six skylight structures at the Lower Roof will be abated and the six skylight structures will be demolished and the skylight openings which are located in the concrete slab beneath the Lower Roof will be closed. The existing roofing and wood support structures at the Lower Roof and Middle Roof will be removed and replaced with new TPO roof membranes and R-30 insulation that will be placed on the existing concrete slabs that support the wood framing. The existing roof membrane and associated insulation materials at the Upper Roof will be replaced with a new TPO roof membrane and R-30 insulation. Guardrails will be installed around the perimeter of the flat roofs; snow rails will be installed at the lower edge of the slate roofs. A roof tie-off system will be installed at the peak of the slate roofs; and a secondary roof drain system will be installed at the Lower Roof and the two drain conductors will be routed through the interior of the building and terminate at the north wall at two sheep’s mouth nozzles. The project involves HVAC work and is described hereafter: a ventilation system will be installed in the attic space to regulate temperature and humidity. The existing rooftop equipment at the Middle Roof and Lower Roof will be removed and reinstalled on the lowered roofs. Existing electrical and mechanical systems which are hung from the mansard ceiling will be re-supported. At the conclusion of the project, the existing site will be restored to its original condition.

Division 07 -	Thermal and Moisture Protection, Dampproofing and Waterproofing, Thermal Protection.
Division 22 -	Plumbing.
Division 23 -	Heating, Ventilating, and Air Conditioning (HVAC).