The 5 signs of mold in your home – spotting damp issues early will help beat it
Experts reveal the warning signs of mold to watch out for
Damp and mold are not things we ever want to find in our homes, but it is important to keep an eye out for them regardless – even when we are sure our homes are safe from damage.
From musty odors to condensation, there are several signs you might have mold even if the pesky black spots themselves have not started to appear yet.
Here, professional contractors and mold removal experts reveal the five most common signs of mold in your home to help you get rid of mold quickly before it becomes more serious.
Signs of mold in your home
Treating the most common types of household mold starts by knowing where and what to look for. Understanding the early warning signs can help you deal with the problem swiftly and avoid disruptive construction work.
1. Discoloration
As with signs of mildew, the most obvious sign of mold is visible discoloration.
Jay Sanders, expert contractor and owner of Castle Dream Construction, says, ‘You should keep looking for visible discoloration on the ceilings, walls, or floors. If you find any sort of black, green, pink, or fizzy white patches, consider it a clear indicator.
‘Never ignore these small patches as mold can spread rapidly,’ he adds. ‘In fact, under ideal conditions, it can double in size every 24 hours.’
2. Damp, earthy smells
If you find yourself constantly asking why your house smells musty despite cleaning and ventilating, then it could be down to some hidden mold.
Peter Duncanson, VP of training and development at ServiceMaster Restore explains that, ‘When mold grows, it gives off a strong musty odor. You can notice the smell when your heater or air conditioner is running. The smell will usually be stronger around a vent that contains the mold growth.’
3. High humidity and dampness
If your home feels humid all the time, or you spot condensation on your walls, the chances are mold is growing somewhere in your space. The mold doesn't cause the humidity, but higher moisture levels provide perfect conditions for mold to develop – especially if you do not reduce humidity in a house quickly.
Russell Vent, VP at Paul Davis Restoration of Greater Rochester NY says, ‘As a general rule, mold needs consistent or prolonged moisture to grow – not simply a one-time spill or wetting. This is an important distinction, as a spilled cup of water on a couch isn’t going to grow mold for the most part, it will be wet and likely dry within a day. On the other hand, a leaky pipe under a sink that drips consistently over the course of two weeks before it is found is almost a guarantee for mold growth. Keep this in mind as you have concerns in your living space.
This mid-sized dehumidifier has a 24 hour timer, three power modes, and a water hose for easy drainage.
‘Water damage is the most important indicator that there may be mold growing, especially if it is on a porous material like drywall,’ he continues. ‘On the surface of the drywall, you may only see yellow water staining but if the moisture source is coming from behind the wall, that painted surface of the drywall will often be more resilient to allowing mold growth since it has a raw fibrous backing – there may be hidden growth within the wall or ceiling cavity.
‘A major sign that you have a high likelihood of mold growth will be condensation on your exterior windows or sweating of exterior walls. This could mean that your windows themselves may be failing or your home is simply too humid. These indicators may not seem like a huge deal when you first identify them, however they are a sign that you have a more universal, atmospheric problem going on, and if not rectified, could lead to a more serious problem.
‘Ensure you are monitoring the humidity in your home with the best dehumidifiers (especially in your basements). Mold thrives in environments above 55% relative humidity.’
4. Blistering or peeling paint and wallpaper
Before you fix peeling paint or wallpaper in your home, consider why it is blistering or peeling in the first place. Unless you have snagged it, the chances are mold is the culprit suggests Jay Sanders, expert contractor.
‘Keep checking the paint – be alert if you find peeling or bubbling. It usually signals moisture buildup behind the surface. You can check it by gently pressing on suspicious areas. If you feel the surface to be soft or spongy, then the moisture may have been trapped underneath.’
Fixing the paint or paper before dealing with the mold will lead to the problem getting worse, and the aesthetic damage recurring.
Amazon's Choice
When dealing with blistered paint, start by scraping the paint away from the area for a flat, smooth surface to work with.
Top rated
With the blistered paint or wallpaper removed you can spray the area to kill the mold. Remember that the mold will come back unless you treat the root cause, so check for water leaks.
Bestseller
With the mold removed and the wall dry, you can then repaint or rewallpaper the area.
5. Allergy symptoms
Mold is one of the most common allergens that plague our homes, and regular household cleaning tips won’t tackle it until you use vinegar to get rid of mold for good.
Peter Duncanson of ServiceMaster Restore shares, ‘One of the biggest concerns regarding mold growth is the negative effects it can have on whoever is exposed to it. Breathing in mold spores can cause some people to suffer from health problems. They can experience coughing, sneezing, nasal congestion, itchy eyes, skin irritation, breathing concerns, headaches, and other allergy-like symptoms. These problems will only worsen the longer one is exposed to mold.’
If your allergies are suddenly worse than ever despite using cleaning tips for allergy sufferers, or you are experiencing allergy symptoms for the first time, it might be time to thoroughly check and treat your home for mold.
You shouldn’t limit yourself to only the most common places to check for mold. These signs can pop up anywhere in your home – even in rooms that don't deal with moisture such as kitchens and bathrooms. Water soaking through walls in excessively rainy seasons and a lack of ventilation can contribute to mold growth in any room of the home, so stay vigilant to avoid lasting damage to your property and health.
Sign up to the Homes & Gardens newsletter
Design expertise in your inbox – from inspiring decorating ideas and beautiful celebrity homes to practical gardening advice and shopping round-ups.
Chiana has been at Homes & Gardens for two years. She spends most of her time producing content for the Solved section of the website, helping readers get the most out of their homes through clever decluttering, cleaning, and tidying tips. She was named one of Fixr's top home improvement journalists in 2024.
-
Introducing CUCINA – ideas, inspiration and expert advice delivered straight to your inbox
Whether you're dreaming of a big kitchen renovation or just in need of some weekday dinner inspiration, CUCINA is bursting full of curated ideas for you and your kitchen
By Caroline Moratti Published
-
I finally found a fun, affordable blender the whole family will enjoy using
Here's my professional chef review of Nutribullet's newest blender
By Lydia Hayman Published
-
4-week countdown – If you're mid-renovation like me, here's how I make my messy house presentable for the festive season, starting now
Who's to say Christmas can't feel special in a half-finished renovation?
By Amy Reeves Published
-
Yes, this is the right time to renovate your kitchen before Christmas – 4 DIY projects you can complete in the next few weeks
Find out what updates are possible before Turkey time
By Amy Reeves Published
-
The 7 quick, inexpensive and transformative jobs I'm doing to spruce up my guest bathroom ahead of hosting season
I decided to give my guest bathroom a makeover ahead of the festivities
By Natasha Brinsmead Published
-
The 4 areas of your home pros say to always insulate to keep it toasty in colder weather – plus, where to never insulate
Knowing where in your home to insulate is as important as knowing where not to
By Natasha Brinsmead Published
-
5 ways to insulate a wall to lower your energy bills and block out noise – and which ones are a mistake to DIY
Pros delve into the different types of wall insulation and ease of installation
By Steve Jenkins Published
-
I tried 5 tricks to keep our home dust-free during our house renovation – this $10 method worked perfectly
Renovations are messy, but this gem was a lifesaver
By Amy Reeves Published
-
How to insulate a garage door – 2 ways to protect this storage spot in cold weather
Insulating tricks and tips from the pros to keep it warm in winter, and cool in summer
By Chiana Dickson Published
-
7 kitchen remodeling mistakes to avoid including lighting, planning and counter space bloopers – and what to do instead
Learn from our experts the most common kitchen remodeling mistakes for you to avoid
By Seraphina Di Mizzurati Published