/ Field knowledge · IMC 502.7 / 502.7.7
A box fan at the roll-up is not 502.7.
Epoxy on a parking slab is still a flammable finish. IMC 502.7: provide exhaust wherever flammable finishes are sprayed or applied — including during construction. IMC 502.7.7: ventilate floor-resurfacing operations so vapors stay well below hazardous levels. A box fan in the garage door is not that path. “It’s temporary” is not a row. House Bill 803 does not exempt mechanical work.
Educational 2024 International Mechanical Code (IMC) 502.7 and 502.7.7 from Daily Code Talk. Confirm the adopted edition. Distinct from a spray booth with an interlock, a dip tank or powder booth, and 404 garage ventilation (the parking floor in normal use). This is not a coating specification and not a cfm. Daily Code Talk does not publish a resurfacing rate here — so this page does not either. Packet: 502.7 floor PDF · ES.
- 502.7 applies during construction. A tenant-improvement epoxy pour, a garage recoat, a showroom grind-and-seal — if the finish is flammable, exhaust is on the path while the work runs and after, until vapors clear.
- 502.7.7 floor-resurfacing: vapors well below hazardous levels. Not a restroom fan. Not the 404 carbon-monoxide (CO) system on the parking floor.
- Do not dump into house return. Do not manifold into toilet exhaust. Recirculating flammable-finish exhaust is the exception that has to be documented — not the default.
- Do not skip the mechanical permit because the work is “just flooring.” Miami-Dade: HB 803 does not exempt mechanical, electrical, plumbing, or structural. More: permit exemptions.
On the set: if the finish work is in the scope, show temporary or permanent exhaust, outdoor discharge, and 502.7 on the note. If the GC says “we will open the roll-up door,” that is the comment.
A box fan at the roll-up door, occupied offices on the same floor
Or a parking-garage recoat with only the 404 fans running. 404 is carbon monoxide in normal use. Floor-resurfacing is a 502.7 finish. Different contaminant. Different row.
Source: Daily Code Talk — IMC 502.2–502.7 · tool: Floor-resurfacing screen · spray: 502.7 spray · dip / powder: 502.7.7 tanks · 404: garage · permit: HB 803.
What to send
That floor-resurfacing or a flammable finish will be applied (including during construction), whether anyone is occupying adjacent space, and where the exhaust actually goes — outdoors, or a box fan at the door.
If the only exhaust is a box fan at the roll-up
Send the finish product and a photo of the space. Masterbuild will say whether 502.7 still has no exhaust during construction — or 502.7.7 still treats a garage recoat as 404.
Send Project Background+1 (786) 398-6940 · osmany.portal@masterbuildconsulting.com
Masterbuild provides engineering services under a written scope. Nothing on this page is project-specific engineering advice, a code interpretation for your project, a coating specification, or a representation about permit approval. Confirm the adopted edition. Exhaust wherever flammable finishes are applied including during construction, and ventilation of floor-resurfacing so vapors stay well below hazardous levels, are 2024 IMC 502.7 / 502.7.7 education from Daily Code Talk — not a cfm and not a temporary-occupancy approval. HB 803 does not exempt mechanical work. This page is not legal advice.