What does this gypsum concrete underlayment final checklist cover?

14 items across 4 sections, covering thickness and hardness, moisture, cracking, protection and handoff. 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 GC's superintendent with the underlayment crew lead, before the flooring contractor takes the floor.

When in the schedule should this walk happen?

After the pour has set and dried and before floor goods are installed, since moisture and soft spots trapped under finish flooring cause callbacks.

Why do these items ask for a photo?

9 of the 14 items call for photo evidence, 12 photos in all. 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 gypsum concrete underlayment final inspection?

Flooring installed before the gypsum dried to the flooring manufacturer's moisture requirement, so the finish floor buckles or debonds. Surface left soft or dusting because the pour dried too fast or was walked too early, and the primer for floor goods won't hold. Thin areas over a high spot in the deck never caught, so the underlayment cracks under load right there.

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.

Free checklist

Gypsum concrete underlayment

Gypsum concrete underlayment final inspection checklist

Gypsum concrete underlayment final inspection is where the punch list is either short or expensive. This checklist walks the finished work the way an owner or AHJ will see it: devices on, systems running, everything labeled. Each item gets the photo that closes it instead of reopening it. Work is commonly verified against manufacturer's published instructions. Confirm the edition your authority having jurisdiction has adopted.

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The checklist

Every item, and the photo evidence it needs

The photo count on each row is what RTI would require before the item can be submitted. Work the list here and watch the gate hold, or load it into RTI and let it enforce the real thing.

Thickness and hardness

Thickness and coverage verified across the floor
Depth checked at edges, penetrations and mid-span, meeting the specified minimum over the high point, full coverage with no exposed mat or deck.
Surface hard and sound, not dusting
Surface scraped or scratch-tested for hardness, no soft or powdery areas, no drummy or hollow spots when sounded.
Surface flat to the flooring manufacturer's tolerance
Straightedge run in several directions, gaps under it compared with the flatness the finish flooring requires, humps and dips marked for grinding or patch.
Doorway and corridor transitions meet without a lip
Poured surface at unit doors, stair landings and elevator sills checked with a straightedge, any ridge or step marked for grinding or feathering.
Surface free of screed ridges, pinholes and trowel marks
Finished face looked at in raking light for ridges, pinholes and rough patches that would telegraph through thin resilient flooring.
Strength test results on file where the spec calls for cubes
Where the specifications require cube samples, the lab results for each pour date on file and compared with the specified strength.
No photo

Moisture

Cured to the flooring manufacturer's moisture requirement
Moisture tested by the method the flooring manufacturer requires, results meeting their limit and documented before floor goods are released.
Drying conditions kept up until the floor reaches its target
Heat on and air moving as the manufacturer recommends, no plastic, stored material or pallets sitting on the floor and trapping moisture under them.
No photo

Cracking

Floor checked for shrinkage and reflective cracks
Surface walked for cracks, especially at deck joints and thin sections, cracks assessed before they're bridged by finish flooring.

Protection and handoff

Floor protected from traffic and point loads while it cures
Traffic kept off until the manufacturer's walk-on time, then boards or runners along paths and under stored material so the surface isn't gouged.
Poured surface clear of other trades' mud, paint and sealant
Drywall compound, paint drips, sealant and oil removed from the gypsum so the flooring primer or adhesive bonds to sound underlayment.
Ceiling below walked for slurry drips and leak staining
Units and corridors under the poured floor checked for slurry that came through the deck, with any staining reported to the superintendent.
No photo
Flooring primer or sealer for gypsum confirmed with the flooring trade
The primer or sealer the flooring manufacturer requires over gypsum underlayment identified with the flooring contractor before the floor is handed over.
No photo
Pour log, thickness checks and moisture results turned over
Pour dates by unit, product used, thickness checks and moisture readings compiled for the flooring contractor and the closeout file.
No photo

What usually sends this back

The failures are almost always the evidence, not the work

Flooring installed before the gypsum dried to the flooring manufacturer's moisture requirement, so the finish floor buckles or debonds.
Surface left soft or dusting because the pour dried too fast or was walked too early, and the primer for floor goods won't hold.
Thin areas over a high spot in the deck never caught, so the underlayment cracks under load right there.

Common questions

6 answers

What does this gypsum concrete underlayment final checklist cover?: 14 items across 4 sections, covering thickness and hardness, moisture, cracking, protection and handoff. 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 GC's superintendent with the underlayment crew lead, before the flooring contractor takes the floor.
When in the schedule should this walk happen?: After the pour has set and dried and before floor goods are installed, since moisture and soft spots trapped under finish flooring cause callbacks.
Why do these items ask for a photo?: 9 of the 14 items call for photo evidence, 12 photos in all. 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 gypsum concrete underlayment final inspection?: Flooring installed before the gypsum dried to the flooring manufacturer's moisture requirement, so the finish floor buckles or debonds. Surface left soft or dusting because the pour dried too fast or was walked too early, and the primer for floor goods won't hold. Thin areas over a high spot in the deck never caught, so the underlayment cracks under load right there.
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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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 12 required photos exist. Approved walks roll into a branded turnover package with a tamper evident record behind every line.