Free checklist
Under-slab vapor retarderUnder-slab vapor retarder rough-in inspection checklist
Under-slab vapor retarder rough-in is the last time the work is fully visible. Once the cover inspection passes and the walls, ceilings and slabs close, every defect left behind becomes a demolition bill. This checklist walks the rough-in in the order the work goes in, with the photo each item needs before it gets buried. 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
- 4
- Built for
- Subcontractors
Who runs it
The sitework or concrete crew preparing the subgrade, or the GC's superintendent walking the pad before the retarder is rolled out.
When in the schedule
After the base is placed and compacted, before the vapor retarder is laid down and before any reinforcing is set on top of it.
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.
Subgrade prepared
- 2 photos
Base fine-graded, compacted and to grade
Base compacted and graded smooth to the slab elevation, no soft spots or ruts, surface tight enough to support the sheet without bridging.
Surface clear of puncture hazards
- 1 photo
Sharp debris cleared before the sheet goes down
Rock, rebar offcuts, form stakes and sharp debris removed from the pad so the retarder can lie flat without being punctured.
Perimeter and depth
- 1 photo
Grade set so the retarder can turn up at the edge
Subgrade elevation at the perimeter set so the sheet reaches the slab edge or footing and can turn up to tie in, not trimmed short.
What usually sends this back
The failures are almost always the evidence, not the work
- Sharp rock, rebar chairs or construction debris left on the subgrade that punches through the sheet the moment a crew walks the pad.
- Base left soft or uneven in spots, so the retarder bridges a void and tears when the slab and crews load it.
- Grade run high or low against the slab edge, so the retarder ends up trimmed short of where it needs to turn up and tie in.
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 4 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 rough-in checklist cover?
- 3 items across 3 sections, covering subgrade prepared, surface clear of puncture hazards, perimeter and depth. 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 sitework or concrete crew preparing the subgrade, or the GC's superintendent walking the pad before the retarder is rolled out.
- When in the schedule should this walk happen?
- After the base is placed and compacted, before the vapor retarder is laid down and before any reinforcing is set on top of it.
- Why does every item ask for a photo?
- 4 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 rough-in inspection?
- Sharp rock, rebar chairs or construction debris left on the subgrade that punches through the sheet the moment a crew walks the pad. Base left soft or uneven in spots, so the retarder bridges a void and tears when the slab and crews load it. Grade run high or low against the slab edge, so the retarder ends up trimmed short of where it needs to turn up and tie in.
- 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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