Free checklist
Under-slab vapor retarderUnder-slab vapor retarder pre-pour inspection checklist
A under-slab vapor retarder pre-pour inspection is the last look at everything the concrete is about to bury: reinforcement, embeds, sleeves, vapor barrier. Once the truck arrives there is no recheck, so this checklist walks the placement in pour order with the photo each item needs before the pour starts. Work is commonly verified against ASTM vapor retarder standards, ACI concrete guidance, manufacturer's published instructions. Confirm the edition your authority having jurisdiction has adopted.
- Items
- 3
- Photos required
- 6
- Built for
- Subcontractors
Who runs it
The concrete foreman placing the retarder with the GC's superintendent, at the hold point right before the pour is released.
When in the schedule
After the retarder is laid, lapped and reinforcing is set, immediately before concrete is placed — the last moment the sheet is visible.
The checklist
Every item, and the photo that proves it
The photo count on each row is what RTI would require before the item can be submitted. Copy the list as is, or load it into RTI and let the gate enforce it.
Continuity and laps
- 2 photos
Sheet continuous with laps sealed to the specified width
Seams overlapped the full specified width and sealed or taped continuously, no open or loose laps, sheet unbroken across the pad.
Penetrations sealed
- 2 photos
Every penetration booted and sealed to the sheet
Pipes, conduit and stub-ups sealed to the retarder with boots or detailed tape, no open cuts left around any penetration.
Damage and edge tie-in
- 2 photos
Tears patched and the sheet tied in at the perimeter
Traffic tears and punctures patched with matching material, sheet turned up and sealed at the slab edge or footing before the pour is released.
What usually sends this back
The failures are almost always the evidence, not the work
- Laps left loose or short so the seam opens under crews and vibration and the barrier is no longer continuous under the slab.
- Pipe and conduit penetrations left with the sheet cut open and no boot or seal, an open hole in the barrier at every stub-up.
- The retarder torn during rebar and crew traffic and never patched, so the pour buries an unrepaired hole nobody can reach again.
Run it with the Photo Gate
A checklist nobody can submit half-finished
Load this list into RTI, stick a QR tag on the area it covers, and the submit button stays locked until every mandatory item is answered and the 6 required photos exist. Approved walks roll into a branded turnover package with a tamper-evident record behind every line.
Submission state
The gate is enforced on the server, so it holds even if the phone is offline when the walk happens.
Common questions
- What does this under-slab vapor retarder pre-pour checklist cover?
- 3 items across 3 sections, covering continuity and laps, penetrations sealed, damage and edge tie-in. Each item spells out what the person walking the job is actually looking for, not just a box to tick.
- Who should run this inspection?
- The concrete foreman placing the retarder with the GC's superintendent, at the hold point right before the pour is released.
- When in the schedule should this walk happen?
- After the retarder is laid, lapped and reinforcing is set, immediately before concrete is placed — the last moment the sheet is visible.
- Why does every item ask for a photo?
- 6 of the 3 items call for photo evidence. A checklist answer without the photo is a claim; the photo is what makes the record worth something in a dispute and lets a reviewer approve work without re-walking the job.
- What most often fails a under-slab vapor retarder pre-pour inspection?
- Laps left loose or short so the seam opens under crews and vibration and the barrier is no longer continuous under the slab. Pipe and conduit penetrations left with the sheet cut open and no boot or seal, an open hole in the barrier at every stub-up. The retarder torn during rebar and crew traffic and never patched, so the pour buries an unrepaired hole nobody can reach again.
- Can I use this checklist in RTI?
- Yes. Start a free RTI workspace, build this list as a checklist, and the Photo Gate holds the submit button until every mandatory item is answered and its photos are attached. Approved inspections roll into a branded turnover package with a tamper-evident audit trail.
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