Section 03.54.13 covers gypsum cement underlayments used for leveling, sound control, and substrate preparation beneath flooring systems. Because gypsum-based products are sensitive to moisture conditions, substrate cleanliness, and primer application, deviations in preparation or environmental conditions can quickly cause soft spots, debonding, or differential curing.The three-phase QAQC flow, Preparatory, Initial, and Follow-Up, ensures substrate readiness before mixing begins, validates the first installation, and maintains consistent performance across all zones. FTQ360 ties substrate photos, CSP documentation, moisture readings, primer coverage, thickness checks, and curing logs into a complete QAQC trail for each area.
This checklist guides inspections from early substrate evaluation through curing and final acceptance. Preparatory steps confirm substrate cleaning, crack repair, moisture testing, required CSP profile, primer compatibility, mix approvals, and environmental controls, directly tied to the root causes of soft spots and debonding.
In the Initial phase, inspectors verify primer coverage, substrate dryness, mix consistency, placement sequencing, thickness, and curing start.
The Follow-Up phase tracks surface hardness, moisture, temperature, working time, placement continuity, and uniformity of finish.
At completion, inspectors document surface condition, hardness, bond, flatness, and any repairs, generating a complete historical record for the flooring installer.
Gypsum cement underlayment has recurring field issues because surface preparation, substrate moisture, mix water, and primer application all interact during placement and early cure.
Most failures originate in the Preparatory and Initial phases, where substrate cleaning, moisture control, and primer timing determine durability.
The failure modes below link directly to FTQ360 checkpoints across all phases.
Root cause: Dust, contaminants, insufficient mechanical prep, or missed primer steps.
Field indicators: Hollow-sounding areas, delamination at edges, shear failure when probing, or inconsistent hardness.
FTQ360 Inspection: Preparatory-phase photos confirm substrate cleanliness and CSP; Initial-phase primer-coverage documentation ensures full bond; Follow-Up bond checks by zone reveal recurring prep issues.
Root cause: Excess water, incomplete curing, cold substrates, or improper mix ratios.
Field indicators: Powdery or chalky texture, surface indentation under foot pressure, soft patches detectable on walk-through.
FTQ360 Inspection: Preparatory-phase environmental controls and mix requirements; Initial-phase logs capture water addition and placement temperature; Follow-Up checks verify hardness and curing duration.
Root cause: Uneven substrate temperature, air movement across the slab, variable thickness, or delayed curing.
Field indicators: Color variation, texture inconsistencies, variable hardness, or patchy softening.
FTQ360 Inspection: Preparatory-phase environmental assessments; Initial-phase curing-start timestamps; Follow-Up temperature and RH logs detect curing inconsistencies by area.
Root cause: Substrate joints not honored, unaddressed cracks, excessive moisture migration, or underlayment placed before substrate stabilization.
Field indicators: Crack telegraphing, curling at edges, or debonding along movement joints.
FTQ360 Inspection: Preparatory-phase mapping of substrate cracks and joints; Initial-phase verification of joint honoring and prep; Follow-Up logs track crack propagation trends across zones.
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Prepare for success by verifying that personnel, materials, equipment, and documentation are ready for work to begin. Inspectors confirm substrate cleaning, crack repair, CSP profile, moisture content, primer compatibility, and environmental conditions.
These checks directly counteract the failure modes linked to debonding, soft spots, and differential curing. Substrate joints are mapped and documented, ensuring they are honored in the topping.
FTQ360 captures substrate photos, moisture readings, primer requirements, and environmental logs so the Initial phase begins with clear, validated conditions.
This phase confirms that work starts correctly. Inspectors verify substrate dryness, primer coverage, mix proportions, placement sequence, consistency, and required thickness.
These checks address the root causes of soft spots, bonding issues, and curing variability. Photos show primer application, pump setup, and the first installed area.
Thickness checks and water-addition logs ensure the installation follows manufacturer standards. Any deviation, coverage gaps, excessive spread, cold substrate zones, is corrected immediately before full production continues.
This phase aims to keep work proceeding correctly. Inspectors monitor surface hardness, temperature trends, moisture, placement continuity, working time, and curing initiation.
These checks tie directly to the indicators seen in the failure modes, powdering, differential curing, cracking, and recurring debonding zones.
FTQ360’s location-linked logs capture zone-by-zone conditions, revealing patterns such as moisture hotspots, uneven airflow, or repeated soft areas that require procedural adjustment.
All of the work culminates with a final result; this phase ensures the completed installation meets project requirements. Inspectors verify hardness, uniformity, bond, curing completion, and repair documentation by location.
Final acceptance includes confirming that substrate preparation, moisture control, and curing requirements were met throughout the work.
FTQ360 compiles substrate photos, moisture logs, primer documentation, thickness checks, and curing records into a complete closeout package for turnover to flooring trades.
ASTM C472 – Standard Test Methods for Physical Testing of Gypsum Plasters and Gypsum Concrete.
UFGS 03 54 13 Gypsum Cement Underlayment
FTQ360 runs on tablets and phones (online or offline), allowing inspectors to capture photos and measurements at the point of work.
Required fields and conditional logic prevent skips and enforce holds. Time and user stamps maintain traceability, and lot/location tracking ties each reinforcement inspection to the pour or structural element.
Dashboards reveal patterns, such as recurring low cover or splice drift, so teams can correct issues before they propagate across floors or shear walls.
Prefer the FTQ360 in-app setup?
Open Checklist Setup → Library, search for the code and tap to clone the checklist.
Then tailor checkpoint templates to your requirements.
If your team still needs paper in select areas, you can print the PDF from the FTQ360 app, mark it up in the field, then transcribe results and attach photos later, just note that paper won’t enforce required fields, conditional logic, or holds like the app does.
For step-by-step help, visit support.ftq360.com.
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