How to Use a Wood Moisture Meter on Drywall

Using a moisture meter on drywall matters for both homeowners and professionals. It helps you find hidden leaks and wet spots before they turn into bigger problems.

Drywall is porous, so it absorbs moisture easily, which can lead to mold growth, damaged panels, and stained or sagging walls and ceilings.

This article explains what drywall is, how to check it for moisture with a pinless moisture meter, and why finding wet drywall early matters.

• What Is Drywall?
• Do Pinless Moisture Meters Work on Drywall?
• How to Use a Moisture Meter on Drywall
• Why It’s Important to Know If There’s Moisture in Your Drywall
• Not All Moisture Meters Have a Relative Mode
• FAQs

With the right knowledge and tools, you can protect your drywall from moisture problems and keep walls and ceilings in good shape in your home or office.

What Is Drywall?

Drywall is a popular building material for walls and ceilings in homes and offices. In the mid-20th century, it began replacing the old lath and plaster technique because it was inexpensive and easy to install. If you live in a home built within the last 60 years or so, you almost certainly live in a home with drywall.

Drywall’s main ingredient is gypsum, a mineral that’s mined in countries around the world. To make drywall, gypsum is crushed, heated, and ground into a powder, then mixed with water and additives and formed between two sheets of paper. In other words, a drywall panel is a gypsum core faced with paper.

Different Types of Drywall

There are different types of drywall. Greenboard is moisture-resistant drywall made with a moisture-resistant facing. You can also buy fire-resistant drywall and drywall that’s flexible enough to create curved walls or ceilings.

Do Pinless Moisture Meters Work on Drywall?

Yes. Orion^® pinless moisture meters have a Relative Measurement mode for non-wood materials like drywall, which makes it easy to find wet spots and help track down leaks.

How to Use a Moisture Meter on Drywall

Detecting moisture within your walls is crucial to maintaining the integrity and appearance of your drywall. Look for visible signs of moisture, such as discolored areas, musty odors, or crumbling drywall, which may indicate significant water damage.

Follow these steps to check the moisture in drywall with an Orion moisture meter:

1. Switch Your Orion Meter to Relative Measurement Mode

Turn on the meter, then press and release the SPECIES/MATERIAL button until “REL” appears in the lower-left corner of the display. Press the ON/HOLD button to go back to taking readings. The meter now reads on a relative scale (0 to 100) designed for non-solid wood and non-wood materials, including drywall. When you’re ready to measure wood again, use the SPECIES/MATERIAL button to switch out of relative mode.

2. Locate a Dry Spot and Record a Baseline Reading

Identify a known dry area on the wall and take a reading. This baseline will serve as a reference point for comparing other readings.

3. Scan the Wall for High-Moisture Areas

Scan the wall for spots that read higher than the baseline. These areas point to moisture in the drywall that may need further investigation or repair.

Why It’s Important to Know If There’s Moisture in Your Drywall

Drywall and moisture don’t get along. Drywall is porous, so it easily absorbs and holds water.

If you splash some water on drywall and wipe it off right away, you should be OK. If it gets wetter than that, dry it with a towel and run a fan on it until it’s dry. However, drywall that stays wet for a long time, or is soaked by a leak or flood, can soften, sag, and crumble, and it usually needs to be cut out and replaced. Drywall isn’t load-bearing, so damaged panels won’t affect the building’s structure, but they do need to be replaced.

Mold is also a problem, because wet drywall gives it an easy place to grow. If you smell mold or see it on drywall, find and fix the moisture source. Porous materials like drywall that become moldy often need to be removed and replaced.

Not All Moisture Meters Have a Relative Mode

Not all moisture meters have a relative mode. A meter set up for wood will still show a number on drywall, but that number isn’t a true moisture content for drywall, which can be confusing.

A relative mode keeps the focus where it belongs: finding the wettest areas. Those are the spots that need to be dried out or replaced, and comparing readings across a wall can also help you trace where water is getting in.

Shop Orion Moisture Meters

FAQs

Can I use a pin-type moisture meter on drywall?

Pin-type moisture meters can be used on drywall, but they leave holes. Pinless meters are generally recommended because they scan the surface without damaging the drywall.

What are the signs that my drywall needs to be replaced due to moisture damage?

Common signs of moisture damage in drywall include discoloration, musty odors, crumbling or warped panels, and visible mold growth. If you notice any of these signs, address the issue promptly to prevent further damage.

How can I prevent moisture problems in my drywall?

Check regularly for leaks, keep rooms well ventilated, control indoor humidity, and use moisture-resistant drywall like greenboard in moisture-prone areas.

Consider reading Wood Moisture Meters Buying Guide: Pinless vs Pin-type next.

If you need tips on how to use a wood moisture meter, read our guide.

Last updated on October 7th, 2026