Trade walkthroughs
How to inspect firestopping
Firestopping is only as good as the last penetration nobody sealed — one open sleeve in a rated wall defeats the rating for the whole assembly. This walkthrough treats firestopping as its own inspection, walked penetration by penetration against the listed systems, because it is the item other trades create and no one owns until you make them.
For the GC's superintendent and QC manager verifying firestopping at rated walls and floors before they are concealed, across every trade that penetrated them.
Step by step
Map every rated wall and floor
Start from the life-safety and architectural plans and mark every fire- and smoke-rated assembly. Everything that passes through one — conduit, cable, pipe, duct — is in scope, so the map tells you where to look.
Match each penetration to its listed system
Each penetration has to be firestopped with a tested, listed system that matches the assembly rating, the penetrant, and the opening. Confirm the installer is working from the specific listing, not caulking every hole with whatever tube is on the cart.
Verify materials and installation
Check that the sealant, wrap, collar or pillow is the listed product, installed to the required depth and coverage with the correct backing. The right product installed to the wrong depth still fails.
Inspect joints and perimeter gaps
Head-of-wall joints, the gap where a rated wall meets the deck, and perimeter slab edges each need their listed joint system. These get missed because they are not a tidy round hole — walk them deliberately.
Check for unsealed and abandoned openings
Look for sleeves left open for a future cable, penetrations a trade added after the firestopper left, and abandoned openings never closed. Any hole in a rated assembly is a breach until it is sealed to a listing.
Document each penetration before cover
Photograph each firestopped penetration and joint tied to its location and listing before the ceiling or shaft is closed. This record is what proves the rating when the AHJ or a special inspector asks, and it cannot be recreated after cover.
What gets missed
- One tube of caulk used for every penetration regardless of the listed system for that rating and penetrant.
- Head-of-wall and deck joints left unsealed because they are not obvious round holes.
- Sleeves left open for a future pull, forgotten and never closed.
- Penetrations created by a later trade after the firestopper demobilized, owned by no one.
- Firestopping concealed above a hard ceiling before it was photographed against its listing.
Questions people ask
- Why inspect firestopping separately from the trades that penetrate the wall?
- Because firestopping is the item every trade creates work for and none owns — a dedicated walk against the rated-assembly map is the only way to catch the penetration each trade assumed someone else would seal.
- What makes a firestop acceptable?
- It has to be a tested, listed system matched to the assembly's rating, the penetrant and the opening, installed to the listing's materials and depth — the right product in the wrong configuration does not hold the rating.
Terms worth knowing
Checklists that make this a one-tap job
Free, field-ready checklists, each with the photo every item needs before it can be submitted.
Related guides
- How to inspect electrical rough-inWalk electrical rough-in before insulation and drywall close it in: boxes, conductors, grounding, supports and clearances, with the photo each one needs.
- How to inspect a fire sprinkler systemObserve and document sprinkler rough-in and final — layout, hangers, heads and hydro test — while the licensed contractor and AHJ run the required hydrostatic and acceptance tests.
- How to inspect drywall before closeRun the pre-drywall walk while the walls are open, then inspect board install: backing, fastening, board type, joints and finish level, with proof at each stage.
Reading the steps is one thing. Proving you walked them is the job.
RTI holds the submit button until every mandatory item is answered and the photos are attached, then chains the record so it can be proven untouched later.