Best Moisture Meter For Drywall

By Asad | Updated

Gypsum, also known as “drywall,” is a widely used material due to its strong fire-resistant qualities. Though, drywall can also get severely affected by moisture as compared to other materials. This a point where the best moisture meter for drywall becomes necessary.

Drywall is extremely sensitive to moisture. You may witness the issues like rapid and excessive growth of mold in drywall due to high contents of moisture and dampness. It’s always better to identify a problem before it gets worse. With that in mind, we will advise you to detect the moisture level in drywall sooner rather than later. Because it is quite costly to repair moldy drywall if not diagnosed timely.

So, how can we detect the moisture in drywall? Or, what is an acceptable level of moisture content in drywall? Which is the best moisture meter for drywall? To assist you, we have compiled to answer all such questions.


General Tools MMD4E 

general tools mmd4e review

Our first pick is the moisture meter by General Tools MMD4E. The unit is of perfect size and features an ergonomic design; therefore, you can easily hold in your hand while working. The user experience is friendlier and holding the unit for a long time is not uncomfortable by any means.

By using this moisture meter you can easily detect the moisture levels in the drywall, in addition, it can also come handy to pick up moisture content from wood and place like carpet’s underneath. So it is a multi-purpose meter. The ability to use it for different surfaces makes it a good choice.

One of the best features of this moisture meter is that it doesn’t only work with drywall or wood. You can also use this meter to detect the moisture in subflooring as well. It is a feature that we did not find in some of the other devices with in the same price range.

The display is clear because of the fantastic LCD that makes the reading clear and easy-to-read display even at night. The pins are made of stainless steel and allow you to penetrate sturdier surfaces. The meter is also suitable to detect the moisture levels in areas that were affected by flooding.

The one significant issue with this meter is that its accuracy is questionable. The makers state its accuracy within ±3%/0.1%. That’s good enough to know the level of water in your walls, but not accurate enough when it comes to dry wood. So far walls this meter is good but if you are a person who would like to have the same meter for wood then you need to consider 7445 reviewed below. If you are on a budget and focus only on the drywall then this meter works for you.

One last thing, the moisture meter has an economical price, and you can purchase this meter for about half of the price of the second moisture meter on this list. But as compared to the quality and overall performance, this moisture meter is suitable but only for home uses or for small projects.  So do not expect it to withstand strong impacts in case you drop or mishandle the device.


Calculated Industries 7445 

best moisture meter for drywall

Next, we have the moisture meter by Calculated Industries. This moisture meter perfectly works as a pin and pinless meter. It has a pinless pad that works very effectively in locating the moisture content affixed inside a wall. During our testing, we find out that the device works accurately on drywall, plaster, brick, concrete, and carpet. Unlike the other meters, it shows the moisture as low, medium, and high. The makers list accuracy of +/- three percent. The ability to tell accurate moisture apart from drywall makes it miles ahead than the MMD4E reviewed above.

It operates with a built-in 9v battery and features an automatic shut off function. So if you leave the meter on, the system detects and power-saving mode comes into effect by turning off the 7445 meters. It is very helpful to conserve the battery and actually reduces the cost to operate the device if you consider the overall savings throughout the year.

The accuracy of this moisture meter is reliable, and overall the unit is simple to use. The accuracy levels are much better than General MMD4E. The moisture level indicator is very interesting and more user-friendly by using the sound. It is a great concept by beeping with higher frequency for more moisture and lower for low moisture content. The frequency does not mean the pitch but rather the speed by which beeps are produced by the meter. The LED display is clear and bright. The overall construction and design of the unit are solid and much better than General MMD4E.

As for the downside, the pins are not that well-built. The pins can fall off or break when used in hardwoods. Also, the plastic material of the pins is not that robust, and that makes it difficult to insert into some materials. For drywall, you can get away with these shortcomings but if you are one of those who like to hit two birds with one shot then be careful with the harder surfaces. Be gentle and 7445 will last for a longer time.

Apart from these drawbacks, the unit is reliable, especially in terms of accuracy. The price is on the higher side as compared to General MMD4E, but its accuracy, display, and performance justify the cost.

How to use a moisture meter

Step 1:

First, set up the moisture meter to detect the level in the surface such as concrete, or drywall.

Step 2:

Now, put both pins of the meter onto the surface. You do not need to push the pins into the wall it will break the bins. Just touch the pins with the wall and gently press it with little force.

Step 3:

The moisture meter will detect the moisture within the wall and display it on the digital display.

How to use pinless moisture meter?

Switch on the moisture meter.

Put the sensors on top of the surface to see the moisture readings. The digital meter will display the moisture content within the wall.

How accurate are readings of moisture meters specially for drywalls?

Moisture meters readings for drywall are usually accurate, but it also depends on the brand and quality of moisture meter. But some moisture meters aren’t that accurate, and their numbers can be distorted and varying. Also moisture content can vary in different spots of the wall so it is better than you take multiple readings at different locations and get an understanding of the condition of the wall as a whole.

What is high moisture reading which should be considered worrisome for drywall?

The moisture reading between five to twelve percent is normal in drywall. The readings between 15 to 17 percent are also reasonable. But readings that are higher than 17 percent are indications of high moisture.

How to detect moisture in drywall without any meter

Since the drywall is sensitive and can get affected by the moisture, it becomes essential to check the levels of moisture in drywall.

So, if you are doubtful that there is extreme moisture in drywall, there are a couple of ways to detect it:

Visual Inspection 

This method is much more like a home remedy and is not scientifically proven. But it works. Often you will find the drywall that has high levels of moisture content is discolored or crumbled. Such are the signs of moisture that you can easily spot with the naked eye and through in-depth inspection of the surface.

Bad Odours 

In many cases, bad odor is the basic indication of excessive moisture in drywall and on other surfaces. The bad odor also indicates the presence of significant mold, and the matter requires your immediate attention.

Both the above-mentioned methods are reliable and effective in detecting the contents of moisture in drywall. But, the problem with both these methods is that they are helpful only after moisture levels are unchecked for quite a while or are too high.

That’s why moisture meters are effective in detecting the precise content of moisture in drywall.

Bottom line:

MMD4E is good for someone on a budget and for those who think the accuracy of a few percentages does not matter. But small percentage changes those lying on the borderline are the ones which suggest what kind of decision can be taken for the drywall. My suggestion would be to go for 7445 it is more accurate and still inexpensive if you consider higher-end meters but still does a great job. Take it as a one-time investment and put faith into a better mid-range meter to give you more accurate readings.