Measure, log, and judge drywall moisture fast. Set a reference, then test multiple wall points. Download results as files and document drying progress easily.
Enter a dry reference reading and multiple suspect readings. The tool compares each point to a computed limit.
This sample demonstrates a dry reference of 12 and an allowed increase of 5 points. The computed limit becomes 17, so any reading above 17 is flagged.
| Reference | Allowed increase | Computed limit | Readings | Result |
|---|---|---|---|---|
| 12 | +5 | 17 | 14, 15, 16, 13, 18 | FAIL |
Drywall moisture screening reduces hidden mold risk and protects finishes. The calculator compares multiple field readings against a practical limit, helping crews decide whether to dry longer, open assemblies, or proceed with coating and paint. Use it for triage after leaks, flooding, or high humidity events.
A reference dry reading should come from a nearby area of similar drywall type, thickness, and backing. Take several checks and use a stable value. Enter an allowed increase that matches your plan, often a few points on the same meter scale, to create a repeatable site limit for the day. For mixed materials, record separate baselines.
Average and standard deviation show consistency across the tested zone. A low average with a high maximum suggests isolated wet pockets near corners, base plates, or penetrations. If many points exceed the limit, suspect broad moisture migration, saturated insulation, or ongoing vapor drive from wet concrete or exterior exposure. Always cross-check with visual cues, odor, and temperature differences, and note whether the meter is used on studs or only on board faces.
When results fail, prioritize source control first: stop bulk water, fix plumbing, and improve drainage. Then enhance drying using air movement, dehumidification, and temperature control. Remove trapped barriers and improve access to concealed cavities. Recheck at consistent points and times to confirm downward trends before closing walls. If readings plateau, consider opening the assembly, replacing affected gypsum, and verifying that wood framing is also trending dry.
Record meter type, drywall type, and units with each measurement set. Keep the same reference method between visits to avoid misleading comparisons. Export the CSV for logs and the PDF for reports, and attach photos of point locations. Establish a recheck schedule until maximum readings remain under the limit consistently. For closeout, retain the baseline value, the chosen increase, and a dated series of results that demonstrates sustained dryness.
Use a project-defined approach: a dry reference reading plus an allowed increase. Many teams start with a small increase for screening, then confirm using specifications and manufacturer guidance.
Meter scales vary by brand, mode, and material density. A local dry reference normalizes the assessment so you can compare suspect points consistently on the same day and surface type.
Take enough points to represent the area: corners, seams, baseboards, and around openings. Five to ten points is common for small rooms, while larger spaces may need more.
It often indicates localized wet spots rather than uniform saturation. Focus inspection on the highest points and check adjacent materials, such as framing, insulation, and floor edges.
No. Combine readings with visual observations, odor, thermal patterns, and knowledge of the water source. Use consistent methods and document meter type, settings, and locations.
Proceed when repeated checks show stable readings under your chosen limit, and the moisture trend is downward. Confirm any additional requirements from coatings, adhesives, or project specifications.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.