Certified Moisture Testing Frequently Asked Questions


Below you’ll find answers to the questions we get asked the most about inspections, mold, and stucco. If you have a question and it’s not answered below give us a call at 651-272-5552 or send us an email info@cmtpros.com we’ll be glad to help you out!

Is it a risk to buy a stucco house?

There is always a risk when buying any home. Stucco siding just gets a bad rap due to repair costs and the large numbers of homes that have been affected. The short answer is; you should not buy a stucco house without having a stucco inspection and test done. 

Though Stucco is durable, yearly inspections should be done for holes, significant cracks, and separation.

Cracks occur which is natural with Stucco, but looks can be very deceiving if larger cracks occur they need to be taken care of quickly, which is why it is so important to have it moisture tested. Moisture tests can help prevent long-term damage because it is what you can't see that matters most. 

What is involved in a stucco inspection?

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Many times a Stucco inspection will start with the inspector doing a visual examination by walking around the home looking for signs of moisture or where moisture could enter the home. This could be a variety of places or things like staining or cracks in stucco, unsealed window joints, trim issues with flashing, sheathing, roof terminations, and around areas like decks and porches

Next, the actual Stucco moisture testing is done from the exterior of the home, there is a debate on where to drill, that you can read about here but we test from the exterior walls because that is where most moisture problems begin.

We drill 2 small holes (3/16” diameter) to insert small probes into that are used to measure the moisture level of the wood structure behind the stucco. After determining if there is water damage behind the walls, we’ll re-seal the holes with color-matched caulk. These small holes will not harm the home.

Our goal at CMT is to help educate you through our inspection of your home. We encourage our clients to be present when inspecting their siding so we can answer any questions and concerns they might have. It can be very helpful in the next phase of your siding process to have the right information. Please give us a call if you have any pre- or post-inspection questions.  

How much does a moisture test cost?

Certified Moisture Testing Services on the job

We bill by time so please call our office for an accurate estimate. Average inspection is about $500. Contact us or call 651-272-5552 to set up an inspection today!

What is moisture intrusion?

Stucco Water Damage corner of house exterior

Moisture intrusion is water that enters the wall cavity through openings in the siding, like windows, or through condensation that occurs in the wall cavity due to warm air leaks.

Here are some signs that you might have moisture intrusion: 


  • Do you have peeling paint?
  • Do you have a moldy or musty odor in your home?
  • Does your irrigation system hit your stucco or homes siding regularly?
  • Are there visual signs of mold or growth?


If so, please give us a call and set up an appointment with Certified Moisture Testing.

What are the problems with stucco houses?

Stucco homes have the same problems that other sided homes have because any home that has repetitive leaking will have damage. Stucco damages tend to occur earlier because of their lack of drying capability.

Is stucco siding bad?

No! Stucco is a great low maintenance product that does a great job of keeping the elements out of the home.  The stucco finish is often strikingly beautiful, offers great flexibility in home design, and provides energy savings.

The majority of the problems blamed on stucco are from leaky windows and improperly flashed wall details. A window that leaks will leak behind any siding, not just stucco.

Do stucco homes get mold?

All homes regardless of the siding can have mold. In order for there to be mold, there has to be moisture. Mold is everywhere, and any home that has a moisture source will potentially have mold.

Moisture testing is important to determine where that is excessive levels of moisture or water damage. Where moisture exists, the likelihood of mold is high.

Is stucco repair covered under homeowners insurance?

It depends on your coverage, some stucco cases are covered by homeowner’s insurance, but usually, your insurance will not cover repairs.

Most damages found behind stucco are the result of construction defects, not one time events. We always advise to at least check with your carrier if there is damage found. It never hurts to ask!

How to tell if drywall is wet?

In some cases it’s obvious like visual evidence of bulging, sagging, or feels mushy, but it’s not always easy to see signs of moisture and damage.

The only accurate way to determine if sheetrock is wet is to use a protimeter. This tool uses an electric current and resistance meter to extrapolate a moisture level.

Other tools only measure either temperature differences or density of the material.

How to measure moisture levels in my house?

A humidistat that measures the relative humidity inside your home is a good judge on whether there is too much moisture in the air of the home.

Also watch for signs of frequent fogging of windows which may indicate too much humidity, especially during the winter months where lower exterior temperatures will cause condensation to occur anywhere air leaks happen in the walls. More condensation could be damaging.

How to detect moisture behind walls

stucco damage exterior wall of home

Probing the exterior walls is the only accurate method for assessing moisture levels. Our tools require small holes, that do not cause damage. This is needed to access the wall cavity and measure the moisture level of the structure in the walls.

What are the pros and cons of a stucco house?

Stucco can give a home a very unique look that is durable, adds value to the home, and does not require additional maintenance than other homes. Stucco can also provide energy savings and can last for 50-80 years! 

The cons are repairs are costly and usually require a professional to make the repairs. The stigma of a stucco home stems from moisture problems

What's an acceptable moisture level in walls?

Probe testing of stucco exterior wall for moisture

The general SPF woods used in home construction should have a moisture level of 19% or less. Typical dry readings are 6-15% depending on the material being tested. Anything over 15% can be considered having a source of moisture that needs to be addressed.

Give us a call and we can always help break this down further for you upon inspection.

How to test for mold in walls?

Since mold requires moisture to grow and survive, we focus on determining if the walls of a home are dry by probing.

If the walls are wet, we source the cause of the moisture and recommend repairs based on the causes and moisture extent.

What are signs of mold in your house?

Signs of mold include:

  • Musty smells
  • Stains on the ceilings and walls
  • Areas that remained wet for over 48 hours
  • Condensation on windows,
  • Bathroom venting not available or used
  • Efflorescence on basement walls
  • Paint peeling
  • Wet carpet
  • Pets with bladder problems
  • Dirty teenage clothes!
How to test for black mold?

Black mold is one of many colors of mold that should be considered potentially harmful. If you can see mold, identify the moisture source, stop the water, and cleanup the mold, in that order.

Mold testing can tell you if you have an actual mold problem in the home, and it’s always best to have a mold test performed by a professional to find and collect the most accurate results.

If no mold can be seen, an air quality test is recommended and will identify if there is a colorful mold in the home or not.


Contact Certified Moisture Testing for your testing needs.

Need an inspection done on your home? We offer a handful of services that can help put your mind at ease when it comes to home issues. Click here to contact us or give us a call at 651-272-5552 We’ll contact you to schedule the inspection.