Structural steel work on an occupied New York City building is a different discipline than new construction. Every modification has to account for what is already standing — existing loads, existing connections, and a building that often cannot stop operating while the work happens. Steel Masters NYC has been fabricating and installing structural steel modifications for commercial and industrial properties throughout New York City since 1972. This article covers four of the most common structural steel scopes we handle: opening closures, plate and column installation, steel supports for machinery, and roof dunnage fabrication.
Opening Closures
When a structural opening in a steel-framed building needs to be closed — whether from a removed door, a relocated stairway, a former loading bay, or a decommissioned mechanical penetration — the closure has to be engineered to carry the surrounding structural load, not just patched over. An opening closure typically involves fabricating new steel framing members that tie into the existing structure at the columns, beams, or studs bordering the opening, then infilling with the appropriate steel decking, plate, or framing system to match the surrounding structure.
This work is common in NYC when commercial spaces are reconfigured for a new tenant, when a building converts use type, or when an existing opening becomes unnecessary after a renovation. Before any fabrication begins, we come out to the site to field measure the opening and document the surrounding structural conditions. Every closure is fabricated to match the exact opening dimensions and the structural conditions of the surrounding steel.
Plate and Column Installation
Steel plates and columns are added to a structure for a range of reasons — reinforcing an existing column that is showing signs of wear, adding a new column to support an added load, or installing base plates and connection plates as part of a larger structural alteration. This work requires precise fabrication, since plates and columns have to align exactly with existing structural members and connection points.
Steel Masters NYC fabricates custom plates and columns in our Brooklyn shop based on field measurements and engineering specifications, then installs them on site. We visit your location to take field measurements before any fabrication begins — ensuring every plate, column, and connection point aligns precisely with existing structural members. Column installation often involves coordinating around existing utilities, finishes, and active building operations — something our crew has handled across hundreds of NYC commercial properties.
Steel Supports for Machinery
Heavy machinery and mechanical equipment — HVAC units, generators, industrial equipment, elevator machinery, and similar loads — require dedicated steel support structures engineered to carry the specific weight and vibration characteristics of the equipment. A steel support platform or frame has to be fabricated to the exact footprint and load requirements of the machinery it is supporting, and positioned to integrate with the building’s existing structural framing.
We fabricate steel machinery supports for rooftop equipment, mechanical room installations, and industrial facility upgrades throughout New York City. Every support structure is custom built — there is no standard size or configuration, since every piece of machinery and every building condition is different. We come out to your location to take field measurements before fabrication and coordinate installation around your equipment and building schedule.
Roof Dunnage Specialists
Roof dunnage refers to the steel support framework that elevates rooftop mechanical equipment — HVAC units, condensers, ductwork — above the roof surface, distributing the load across the structural roof framing and allowing for proper drainage, access, and equipment clearance underneath. Dunnage is one of the most common structural steel scopes on NYC commercial and industrial rooftops, where mechanical equipment is frequently added, replaced, or upgraded.
Steel Masters NYC fabricates and installs roof dunnage systems including elevated platforms, equipment rails, and steel catwalks for rooftop access. Every dunnage system is built around the specific equipment being supported and the structural conditions of the roof it sits on. We come out to the site, take field measurements, and fabricate the dunnage to fit your exact rooftop layout. We work directly with property managers, general contractors, and mechanical contractors to coordinate dunnage installation around equipment replacement and upgrade projects.
Who We Work With
Structural steel modification projects typically involve coordination between several parties — building owners, general contractors, engineers, and mechanical or electrical contractors. Steel Masters NYC works as a fabrication and installation partner within these projects. We come out to the site to take field measurements, prepare detailed shop drawings for engineer review, fabricate in our Brooklyn shop, and install with our own crew. We have been providing shop drawings for over 40 years and can provide calculations and stamping if required on the drawing. We do not provide engineering or design services — we fabricate and install to the specifications provided, working alongside your engineer or architect of record.
Service Area
Steel Masters NYC fabricates structural steel in our Brooklyn shop and installs throughout Brooklyn, Queens, Manhattan, the Bronx, Long Island, and Westchester.
Get a Quote
Call us at (888) 577-8335, fill out the request form on our website, or email your specs and drawings to steelmastersnyc@gmail.com. We can schedule a site visit to take field measurements and provide a written quote for your structural steel project.
