The short answer
Types of Moisture Meters
Moisture meters come in two main styles: pin-type and pinless. Pin-type meters have two metal prongs that you push into the drywall. They measure electrical resistance between the pins, which changes with moisture content. Pinless meters use a flat sensor pad that you hold against the surface without piercing it.
Both types give a numerical reading, but the scale differs. Pinless meters often show a relative value from 0 to 100, while pin-type meters display a percentage of moisture. Always check the instruction manual for the specific scale your meter uses. The manual also tells you the correct depth for pins and the right pressure for the sensor.
How to Take a Reading
Start with a clean, dry surface. Wipe away any dust or loose paint with a dry cloth. For pin-type meters, insert the pins at a shallow angle, about 1/8 inch deep, into the drywall. Press firmly but do not force. For pinless meters, place the sensor flat against the drywall and apply even pressure.
Hold the meter still for a few seconds until the reading stabilizes. Move the meter to several different spots on the same wall, especially near corners, baseboards, and where water damage is suspected. Take readings at different heights as well. Moisture can travel upward from a leak, so check both low and high areas.
- Wipe the surface clean before testing
- Test multiple spots on the same wall
- Check near edges and corners
- Hold the meter steady for a stable reading
- Compare readings to the reference chart
Interpreting the Numbers
A reading below 15 percent on a pin-type meter usually means the drywall is dry. Between 15 and 20 percent suggests some dampness, which may be from high humidity or a slow leak. Above 20 percent indicates that the drywall is wet and likely needs attention.
Pinless meters use a different scale. A relative reading below 50 is typically dry, 50 to 70 is damp, and above 70 is wet. But these numbers vary by brand and model. The key is to compare readings from the same wall over time. If the number rises, moisture is increasing.
What to Do with the Reading
If you find a high moisture reading, the first step is to find the source of the water. Check for visible leaks from pipes, roofs, or windows. If you cannot find the source, a leak detection service can help. The pros use specialized equipment to trace hidden water flow.
Do not ignore a high reading. Even if the drywall looks fine, moisture can lead to mold and structural damage. If the drywall feels soft or crumbles, it may need replacement. For minor dampness, improving ventilation and using a dehumidifier can help dry it out. For persistent wetness, consider consulting local water damage pros.
When to Call for Help
A moisture meter is a useful tool, but it only shows surface moisture. It cannot tell you if water is inside the wall cavity or behind the drywall. If readings are high in multiple areas, or if you see stains, bulges, or a musty smell, the problem may be larger than a simple surface issue.
In that case, a water damage inspection can give a clearer picture. The pros use moisture meters along with thermal imaging and other tools to find hidden moisture. They can also help with structural drying and dehumidification to prevent further damage. If you live in Layton, you can search for local water damage pros to assist.
- High readings in many spots
- Visible water stains or bulging
- Musty odor coming from the wall
- Drywall feels soft or crumbles
- Leak source not obvious
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Call (801) 383-0232 any time, day or night, and describe what happened.
Call Now (801) 383-0232Frequently asked questions
What is a normal moisture reading for drywall?
For pin-type meters, a normal reading is below 15 percent. For pinless meters, a relative reading below 50 is usually dry. Readings above these levels suggest dampness. Always compare to the meter's manual, as different brands have different scales.
Can a moisture meter damage drywall?
Pin-type meters leave small holes, about 1/8 inch deep, which are usually minor and can be filled with spackle. Pinless meters do not damage the surface at all. Use the shallowest pin setting to minimize marks.
How often should I test drywall after a leak?
Test the affected area every few days for at least two weeks. Moisture can spread slowly, so early readings might not show the full extent. If readings stay high, the drying process is not working. Continue until readings drop below the dry threshold.