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How Do You Check for Moisture in Walls? A Step-by-Step Guide

How Do You Check for Moisture in Walls? A Step-by-Step Guide

Try as you might to avoid it; the fact of the matter is that moisture in homes is mainly unavoidable.

The typical activities in most homes — such as running baths, boiling water on the stove, and even just the breathing of multiple individuals — tend to cause moisture even in dry climates.

So, moisture happens.

Still, there’s no reason why it needs to strike fear in the hearts of every homeowner.

The key, though, is catching the problem early enough, making a practice of checking for moisture damage regularly, and not just when a situation becomes overwhelmingly apparent.

Follow this step-by-step guide to make sure that moisture never catches you or your walls unaware.

Why Moisture in Your Walls is an Issue:

Most well-built homes are designed and constructed with the wear and tear of daily moisture factors in mind and come complete with protective barriers, high-tech infiltration systems, and siding made from materials meant to repel dampness. Still, though, the moisture always manages to work its way in regardless over time.

When the inevitable moisture damage strikes, you and your home are both at risk for several reasons.

Firstly, wood and gypsum, the materials used to make drywall, are relatively soft and susceptible to rot. Should your house’s frame or drywall become compromised, the result could be dangerous and cost massive amounts of money to repair.

Second, moisture tends to also produce a slew of unhealthy growth, like mold and mildew, when left to linger for too long. Walls, primarily, provide excellent breeding grounds for moisture-related development, as their interiors are hidden from sunlight and fresh air.

Not only are these substances unsightly, but they also can cause harm to your respiratory and neurological systems if breathed for too long.

Your health and safety are far too important to put at risk because of something as avoidable as moisture in your walls. If caught early enough, you can still successfully save your walls from the destruction of built-up moisture, so best to check early and often.

Read more: What is acceptable moisture for drywall?

Moisture Droplets

Steps for Checking Moisture in Walls:

Checking for moisture inside your walls is not a one-size-fits-all experience. There are plenty of reasons for wanting to avoid overly invasive measures right off the bat.

Here is a progressive scale from least to most invasive for those looking to learn all the moisture-checking techniques.

1. Look for Visual Signs

Often, moisture damage in or on a wall is noticeable with a close visual inspection or, in extreme circumstances, even a quick spot check.

Suppose the damage has progressed to the level of causing mold or mildew growth. In that case, you should be able to spot green and black spores lurking sneakily along the edges between the wall and ceiling, behind heating ducts, along window panes, or even sprouting openly.

However, if there’s not yet visible mold, moisture damage can still be spotted on or around walls through a couple of other telltale signs. Peeling paint, yellowish discoloration, and warping or buckling surfaces are all pretty apparent alerts of a problem bubbling underneath.

All crevices are just moisture trapping and mold growth opportunities, so leave no wall unturned.

Read more: Mold vs mildew on a drywall 

2. Pay Attention to Strange Smells

Have you ever walked into a room and been struck by an unpleasant musty smell that makes you want to turn around and walk right back out? Chances are that an issue with moisture in the walls was to blame.

When mold and mildew begin to grow and spread, they emit a pretty apparent scent of dampness, which can be a helpful tool for identifying a problem.

Other items in a room can also collect moisture and signal mold growth, such as curtains, bathmats, towels, and carpets.

If the distinctive smelliness sticks around after a thorough wash of all nearby fabric, though, then you likely have a moisture problem in the walls instead.

To be extra careful, you can try directly smelling the walls to see if the scent increases. You’ll probably feel silly, but it’s better than the alternative.

3. Push to Test Strength

As mentioned above, drywall tends to be very soft and pliable, especially when damp. If a significant moisture problem is present, you’ll be able to tell by doing a light press on the wall to see if there’s any noticeable give.

Don’t just do one push and done, though. Experts suggest inspecting your walls strategically to see if you can detect a slight depression in the drywall, which is likely due to increased dampness.

If you can’t see any obvious areas to test, try pushing all across the wall at random intervals, from floor to ceiling to door.

4. Administer a Moisture Meter

Perhaps there are no soft spots or smells, but you still have reason to believe that a moisture problem is in your walls and waiting to strike.

The only way to know for sure is to get in there and check it out from the inside. There are several different moisture meters on the market, but all involve a slight amount of drilling and excavating.

Generally, you’ll be required to take a small screwdriver, knife, or another sharp tool, make a slight hole and slide the meter inside. The meter will then give you an official reading on the moisture levels in the general vicinity of its insertion.

Getting a reading that registers some moisture can be expected with basically every probe test, as no dampness at all is completely unrealistic. However, anything above roughly 13% is cause for further inspection and potential repairs.

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Moisture checks don’t have to be tricky! In fact, by following this progressive guide, you can make sure your walls are dry with minimal and noninvasive effort in most cases.

If still in doubt, however, give All Dry USA a call. The professionals here are experts at spotting moisture problems and resolving them quickly!

Contact us now and let us help you!


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