High Society Kustom Garage

Car interior mould

For a predicted dry summer thanks to apparent El Niño events, we’ve sure had a lot of rainfall in Queensland in the past 6 weeks.  Whether you are excited about the rain or longing for a dry spell, you need to prepare for the moisture ahead.  Rain increasing the already high humidity we have at this time of year means people are noticing mould forming in their houses.  This means that your car interior is susceptible to mould too.  Especially cars that see infrequent use.  According to NSW Health “Health effects of mould exposure include a runny or blocked nose, irritation of the eyes and skin, and sometimes wheezing. For people with asthma, inhaling mould spores may cause an asthma attack.”

What is mould and why is it growing in my car interior

Mould is part of a group of very common organisms that also include mushrooms and yeast.  It is present virtually everywhere and may grow in wet or moist areas without adequate ventilation.  The problem usually begins with excess moisture that doesn’t have a chance to dry properly.  This could be from having wet occupants in the vehicle before being parked, something being spilled, or a leaky seal around a door or window.  If you spill a bottle of water and leave your car in the garage overnight, you could wake up to the growth of mould in your car.  Excess heat and humidity will only make the problem worse.


Mould will quickly begin to grow on wet surfaces, usually absorbent materials such as carpet, fabric, and leather.  Mold spores are microscopic and invisible to the naked eye but can grow to the point where it does become visible.  These spores may start to spread around the inside of your vehicle, especially if you turn on the A/C or heat.  Usually, the first sign of mould is the musty, unpleasant odour.

Prevention is better than cure

Often, prevention is the most effective remedy, and dealing with mould in the interior of a car is no different.  The best thing you can do is to keep your vehicle dry, clean and well-ventilated when parked.  One of the simplest things you can do to prevent mould from appearing is to ensure that you do regular cleaning.   Vacuum up any crumbs or bits of food that might have been dropped on the floor mats or down the sides of the seats.  Soak up any liquid spills immediately, and clean with a suitable cleaner for the surface.  You can also purchase moisture-absorbing packs to leave in the car.

Get rid of the car cover

It may seem like a good idea to protect your vehicle from with a car cover.  Unfortunately, mould grows in moist, poorly ventilated environments.  A cover traps moisture and does not let air flow through the vehicle.  Mould also thrives in the absence of natural light.  Unless you plan on pulling back the cover for a few hours every day, you’re best to leave the cover off for a few days after a large downpour.

Ventilate the garage

The garage is a great place to keep your car dry, but the air will still hold moisture if the area is not well-ventilated.  If there’s no natural light available, the garage then becomes an ideal place for mold to find its way into your vehicle’s upholstery.  Metal sheds are even worse, especially if they’re uninsulated, as they tend to get condensation on the inside anyway.  Don’t forget to leave the car windows down a little if it’s parked safely indoors to allow for ventilation.

Mould removal

If you have mould in your car, act fast to remove it as safely as possible.  Time is of the essence when it comes to cleaning up mould.  The longer it sits in your car, the farther it will spread.  Mould can also damage the underlying surface if left too long.  It will continue to spread into the carpet or upholstery the longer it grows, which could destroy your upholstery permanently.  Firstly, inspect the area, as large pools of water pooled on the floorpan may make it necessary to remove the seats, carpet, and underlay completely. 

Find all the affected areas and treat them at once to get rid of mould for good.  As you do your inspection, keep in mind that you can always hire a professional.  An experienced detailer may have more luck in removing the mould by knowing how to attack it properly and having the correct equipment to do it.

Starting the process

Allow as much light and fresh air as possible to prevent the mould from spreading further.  Roll down the windows and if possible, do any cleaning out of the garage.  Avoid working in confined areas with poor ventilation.   You can start loosening the mould spores using either a brush or a vacuum.  If the mould is too moist, this may not work.  You can attempt to break up stubborn mould stains on the surface with a rag or paper towel.


After eliminating all visible mold, you need a strong cleaner capable of penetrating through the dirt and remaining mould spores.  For the best results, use a dedicated mould-killing solution to remove the mould spores and prevent their return.  Make sure to wear a mask, gloves, and ventilate your space well when using such products.  Always follow the instructions on the packaging.

Carpet cleaning

To clean the carpet and floor mats, it’s a good idea to begin with a wet/dry vacuum.  Suck up any excess water.  Thoroughly clean the carpets with a good fabric carpet cleaner, particularly one with disinfectant properties.  You may want to follow this with a steam cleaner.  Once the area has dried properly, vacuum the surface again.  If your vehicle has a musky or damp smell but there doesn’t appear to be any mould present, then it may be that there is mould underneath the carpet.  This is where the removal of the seats and carpet becomes necessary.

In extreme cases, removing and cleaning your carpet and the materials beneath might not be enough.  You may need to replace the carpet and underlay outright.  Whether you remove your carpet to clean it or replace it, be sure to clean the steel floor too as any mould in the vehicle needs to be entirely removed as it can quickly grow back.

Seat cleaning

Seats and other soft upholstery will need to be cleaned in the same way.  This may mean having a motor trimmer completely strip the seats down so that foam can be steamed and dried completely.

Don’t forget to clean the roof liner, door trims, and dashboard, and wipe over the interior glass, as well as inside any storage compartments.  Clean the vehicle’s upholstery with cleaning products that have antimicrobial ingredients.  These ingredients discourage mould growth.  Once finished, leave the vehicle with all doors open to allow adequate ventilation.

Interior mould

Not only is car interior mould smelly and unsightly, but it can also be very dangerous.  Mould spores can cause severe respiratory issues, especially in children, the elderly, and people who suffer from asthma and other existing conditions.  Keep that in mind this rainy season.  If you feel that you have lost the battle with mould, you may want your interior replaced so that the mould does not spread all over the vehicle.  High Society Kustom Garage is here to help.

Example of car interior mould
Dashboard removed because of car interior mould
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