The subtle nature of mold growth means that it is generally hard to detect in the initial stages. It is however possible to follow the clues and identify the problem.

A stale musty smell in a strong indicator that mold may be growing in your home. This is because mold is usually known to grow in damp spaces.

Mold growth can however only be confirmed by examining the areas in which you suspect the same. Such areas include electrical outlets, leaking pipes and discoloured surfaces.

The following are the major signs of mold infestation in your walls:

Visible Mold Spores

Visible mold spores are known to produce a dark blackish and greenish discolouration. Visibility is usually a sign that there is a bigger mold problem beneath the surface on which the pores appear.

As such, using detergents to scrub off the visible mold is regarded as treating the symptom instead of the sickness. Clients are therefore advised to seek the advice of mold remediation experts.

This is usually the best way to not only remove the mold in its entirety but also fix the source from which it came from.

Signs you have mold in the walls

Lingering Respiratory Issues

It is normal to suffer from respiratory challenges as a result of common colds from time to time. However, when such challenges become common and recurrent, it may mean that you are battling a mold infestation problem.

This may especially be true if you find yourself frequently nose-bleeding. Visiting a health practitioner may help in unearthing the source of such bleeds.

Another way to test this hypothesis is to leave the space in question for a number of days. If the symptoms only recur upon your return, then it is proof positive that your environment has been compromised.

Stale Smell

A stale smell is by far the most common indicator of mold infestation on your walls. It is however important to note that mold exists in different species which means each kind has a distinct smell. With this in mind, clients are usually advised to investigate any uncommon odor in their premises.

Flooding History

Previous flooding is one of the greatest causes of mold infestation. This therefore means that one should continually check the areas that were formerly infested with mold in order to avoid any re-infestation.

Drywall in particular has a tendency of facilitating mold growth within 48 hours of direct exposure to water. In such cases it is usually advisable to cut the drywall up to a minimum of one foot above the water level.

The major signs mold growth in drywalls include peeling of walls, discoloration and bulging walls.


One of the most accurate signs of excessive moisture in a place is certainly the presence of rust. Where rust is prevalent, mold is definitely not far behind. This is because both are known to grow under the same moist and damp conditions.

How to test for Mold in the house

There are certain protocols that one can engage when looking to discover the presence of mold in a certain area. They include:

Bleaching, Dark and Discoloured Areas

Bleaching is a great way of differentiating a mildewed surface from a dirty and stained one. This is normally done by pouring a little bleach on the said area. The bleach should be diluted with water in a 1:16 ratio and applied with a swab

Stained areas usually remained darkened for longer periods of time when compared to their mildewed counterparts. Mildew also tends to occur on moist surfaces that include showers and wet deck boards as opposed to dirt which occurs randomly.

It is however important to note that such mold test kits can only be able to determine the presence and not the source of the mildew.

Surface Piercing

This method is particularly suitable for wooden surfaces. This is because mold usually has a tendency of making wooden surfaces soft and flaky upon infestation. This softness can mature to full-blown rotting if the growth is not curtailed.

Clients are thus advised to pierce suspected wooden surfaces using sharp implements such as screwdrivers. Surfaces that are found to be softer and weaker than usual are most likely mold infested.

Investigate Internal Plumbing

Water drainage systems are generally a prime place for mold to grow especially in cases where they are leaking. Such leaks also cause mold growth in the areas surrounding the said plumbing fittings.

It is thus advisable to check the areas above, below and adjacent to the drainage system so as to get a full picture of the extent to which the mold has grown. Fixing the leak immediately is also recommended as far as stopping the source of the mold is concerned.

Ductwork Inspection

When ductwork is not installed and insulated properly, mold may form under the register on the ceiling. This is usually a result of the condensation of air into water on such ducts. This in turn leads to the transmission of cold air into the attic.

Drywall is known to harbour mold spores in cases where such condensation happens regularly. It is thus advisable for clients to engage mold experts in checking for mold on their ducts.

Examine External Leakage

Mold can sometimes begin to grow on the outer surface of either a wall or a ceiling. The first thing to do when this is suspected is to identify one of such leaks and test for mold therein.

You can then find the spot on the other side of the wall where the mold growth is likely to have begun. It is also advisable for one to inspect nearby drainage features such as vents and roof flashing units.

This is usually to ensure that such drainage features are not spouting any excessive water on, near or under the wall. In cases where they are, proper flashing units should be installed.

What are the symptoms of getting sick from mold?

Even though exposure to mold is known to result in some side effects in terms of health, it has not been proven to cause chronic illnesses. Such side effects include:

Allergic Reactions

Allergic reactions are known to manifest in people who are overly sensitive to mold. These reactions generally produce a wide range of symptoms in different people. Such symptoms include a running nose, dry coughs, skin rashes, sore throats and wheezing just to mention a few.

Worsening Pre-existing Conditions

This is particularly common among people who are battling respiratory conditions such as asthma. For such patients, exposure to mold may result in difficulty in breathing due to shortness of breath.

Fungal Infections

Healthy people seldom get fungal infections when expose to mold. This may however be the case for those with compromised immune systems such as cancer patients.

DIY vs. Hiring a Mold testing expert

When testing for mold, it is important to engage the best technique in order to obtain accurate results. Depending on your requirements, the most appropriate technique may either be doing it yourself or hiring an expert.

Do it Yourself


  • Affordability is certainly one of the major advantages of testing for mold yourself. This is because do-it-yourself testing utilises common materials such as plastic bags and tapes which are easily available. Buying a home testing kit is also rather cheap.


  • Inaccuracy is certainly the main hindrance as far as do-it-yourself mold testing is concerned. This inaccuracy is due to the fact that home mold testing kits only ascertain the presence of mold in a given area.
  • While this is important, it also means that such kits cannot be able to reveal other important demographics which include type, location and source of the mold.
  • Without such demographics, it is practically impossible to know the extent to which your home is infested with mold. It is also extremely difficult to identify the best mold removal technique without such information.

Hiring a mold testing expert

Hiring mold testing experts is generally recommended as the best technique when looking to eradicate mold in your home. is a great tool that quickly matches you with the best mold testing and remediation specialists in your locality. You can get three estimates from local mold testing and remediation professionals in a matter of two minutes. Kindly follow the steps below to enjoy this great service:

  1. Scroll to the top of the page and enter your zip code
  2. Answer questions about your drywall job
  3. Your mold testing and remediation details are forwarded to three local experts who will send you a price estimate for your job with some friendly advice.

The following are the major advantages and disadvantages of hiring a mold testing expert:


  • Accurate mold assessment is one of the major benefits of hiring a mold testing expert. Mold testing experts are usually able to determine the presence or absence of mold in areas beyond the scope of do-it-yourself practitioners.
  • After identifying the type, location and source of the mold, experts are also able to recommend the right techniques to apply in order to effectively remove the mold.
    These techniques include fixing the source, controlling humidity, physically cleaning the mold and even installing future mold prevention features.


  • Hiring a mold testing expert may be effective but it is certainly not cheap. This is the main reason why people opt for do-it-yourself techniques instead.


Excessive moisture concentration is certainly the main cause of mold infestation in a house. This moisture may be a result of water spillage on the surfaces as a result of leakage.

Yes, it is. This is because of its ability to keep eating into the infected building materials if not curtailed. This eating can eventually lead to softening of and damage to your walls beyond repair.

Blood and skin prick tests are usually utilised by medical practitioners when testing for mold exposure on individuals. Mold testing professionals and home testing kits are however used when looking to test for mold exposure in a home setting.

Timothy Munene
Author: Timothy Munene - Timothy is a freelance writer and an online entrepreneur.