Firestopping & Fireproofing FAQ

Firestopping is a passive fire protection method that seals openings and penetrations in fire-rated walls, floors, and ceilings to prevent the spread of fire, smoke, and toxic gases between building compartments. In New York City, firestopping is required by the NYC Building Code for all penetrations through fire-rated assemblies. Without proper firestopping, fire can travel rapidly through a building via gaps around pipes, cables, conduit, and HVAC ducts — defeating the purpose of fire-rated construction.

Any penetration through a fire-rated wall or floor assembly requires firestopping. This includes pipe penetrations (plastic and metal), electrical conduit penetrations, cable and cable tray penetrations, HVAC duct penetrations, and combination penetrations with multiple services. Construction joints, perimeter joints, and head-of-wall joints also require firestopping. If you're unsure whether a penetration needs to be firestopped, contact Ali Firestop — our team can review your project plans and advise.

A UL-listed firestopping system is a specific combination of firestopping products, substrate materials, and installation details that has been tested and certified by Underwriters Laboratories (UL) to meet ASTM E814 (UL 1479) fire test standards. NYC Building Code requires that all firestopping assemblies be UL-listed. Each UL system has a unique number (e.g., WL 1000, FL 5600) that identifies the exact installation conditions under which it was tested and approved.

Common signs that firestopping needs repair include visible gaps or cracks around pipes and cables passing through walls or floors, areas where fireproofing appears to have been removed during construction or renovation, failed DOB or special inspector reports citing missing or damaged firestopping, or visible damage from water intrusion or physical impact. Ali Firestop offers firestopping inspections and assessments — contact us to schedule a site visit.

Spray-Applied Fire Resistive Material (SFRM), commonly called spray-applied fireproofing, is a cementitious or gypsum-based material sprayed onto structural steel, concrete, and other building elements to provide fire resistance. It is the most common method of fireproofing structural steel in commercial buildings. SFRM slows the transfer of heat to the steel, allowing the structure to maintain integrity for the specified fire resistance rating — typically 1, 2, or 3 hours.

Intumescent fireproofing is a thin-film coating that expands dramatically when exposed to heat, forming an insulating char layer that protects structural steel. Unlike spray-applied fireproofing (which is thick and textured), intumescent coatings are thin (1–5mm) and provide a smooth, paint-like finish. This makes intumescent fireproofing the preferred choice for architecturally exposed structural steel where aesthetics matter. Both systems provide equivalent fire ratings but serve different applications.

Yes. Ali Firestop works directly with general contractors, construction managers, building owners, property managers, and developers. We are experienced at coordinating our work with MEP trades, drywall contractors, and other site teams to minimize schedule impacts. We can provide subcontractor bids, participate in pre-construction meetings, and work within your project schedule.

For standard projects, Ali Firestop can typically mobilize within 1–2 weeks of contract execution. For urgent or emergency repair situations, we will do our best to accelerate scheduling. Contact us to discuss your project timeline and we will work with you to meet your schedule.

Yes. Ali Firestop provides complete documentation for all firestopping and fireproofing work, including as-built drawings, UL system numbers, installer certifications, product data sheets, and test results. This documentation supports your DOB filings, special inspection requirements, and certificate of occupancy applications.

You can request a quote by calling us at (212) 555-0199, emailing info@alifirestop.com, or submitting our online quote request form. For accurate pricing, it helps to provide project plans, specifications, and the scope of firestopping or fireproofing work required. We will review your project information and provide a competitive, detailed proposal.

Ali Firestop serves all five boroughs of New York City: Manhattan, Brooklyn, Queens, the Bronx, and Staten Island. We also serve nearby areas in the New York metropolitan region. Contact us to discuss projects outside of the five boroughs.

Yes. Existing buildings in New York City may require firestopping when undergoing renovations that disturb fire-rated assemblies, when changing occupancy, when adding new mechanical, electrical, or plumbing systems, or when existing firestopping is found to be damaged or missing. The NYC Department of Buildings may require firestopping work as a condition of approving renovation permits or issuing a certificate of occupancy. Ali Firestop can assess existing conditions and provide compliant firestopping solutions.