So you have decided to leave your vehicle in your South Carolina garage for the summer while you spend time in Maine, Michigan, Vermont (or wherever home away from home is) to get away from the Lowcountry’s hot and humid summers.
What happens if you get back to the Lowcountry in October, open up your car door, and see white mold all around your steering wheel, dashboard, and leather seats? And to make things worse, your car won’t start and you have flat spots on your tires? Did you as the homeowner do something wrong? What could have been done to prevent such issues? Well, when conditions are right, mold can grow and can spread very quickly in your vehicle and your vehicle battery can drain quicker than you may think.
Preparing your car when you leave is critical in the Lowcountry to avoid issues with your engine, tires, mold, and more. Below we have laid out the answers to the most commonly asked questions we receive at the House Butler by our clients.
Where Should I Store My Vehicle?
Where you store your vehicle is important and we know each client’s situation is different. Varying circumstances determines the necessary steps you should take.
Storing Your Vehicle Outdoors
The worst thing you can do is to leave your vehicle outdoors for an extended period but we realize for some clients this may be their only option.
- Protect Your Vehicle Against the Elements (Including Pests) – If your vehicle must be outside, it is important that you secure your car with an all purpose weather cover to not just protect your car from the elements but also from pests. This can be especially true in the South Carolina Lowcountry as rodents and other pests can make their way inside your car and can damage vital internal parts. We even recommend putting repellant inside the hood of your car as a deterrent.
- Avoid Direct Sunlight – Further, avoiding direct sunlight is important as it will fade the exterior paint of your car, the color of the car, and (most importantly) increase the internal temperature of the car which can be an ingredient for mold. Therefore, park your car underneath a car port. If a car port is not available, parking underneath trees can also help protect your vehicle from the direct sunlight.
- Don’t Forget Storm Season – But be wary, if you are going to be gone during storm season (June 1 to November 30) do not park your car under any trees with heavy branches to avoid potential damage.
- Mold Is Public Enemy Number One – Mold can be a serious issue for your car in the Lowcountry because mold growth within cars can begin when the relative humidity reaches 55%. During the hot and humid summer months in South Carolina, the relative humidity can average near 90% during peak hours. Therefore, storing your car outdoors is always a last resort solution
Storing Your Vehicle Indoors
The best option is leaving your vehicle within an air-conditioned storage unit, though we understand that this is not realistic in most circumstances. Leaving your car in a garage is the next best option. However, simply storing your car in your garage for an extended period is just step one to prevent mold or other issues.
Controlling Humidity In a Garage
Most garages are not climate controlled so it is important to take steps to manage the humidity.
Consider purchasing a box fan from a Home Depot or Lowe’s and setting it sturdily in your garage. Also purchase a manually programmable timer to connect the fan to. A suggestion would be to set the timer so the fans turn on every day between 12 pm and 5 pm. The fan turning on will circulate the air in your garage during the hottest, most humid part of the day.
Installing a ceiling fan in your garage and simply letting it run on low is also a great way to have continuous air circulation in your garage.
You can also purchase a portable dehumidifier for your garage and program it to maintain a relative humidity below 55% but nothing below 35% (a level that will cause drying and cracking to leather seats and material). When using a dehumidifier, whether it is a self-emptying model or a manual, it is important to have a home watch professional monitoring and or emptying the unit in your absence.
Leave Vehicle Windows Opened or Closed?
Everyone has their own opinion on this, however let’s examine both scenarios.
If you leave the windows open about 5 to 6 inches, it will allow air to circulate throughout your vehicle, especially if you install the box fan (suggested above) in your garage. Air circulating is healthy for your vehicle and doesn’t allow humid air to sit stagnant in your vehicle. It also makes it a tad harder for potential mold pores to easily settle on your vehicle’s interior surfaces and spread.
But here is the issue: if your garage has a roof leak and rain water (moisture) enters your garage, the uncirculated humid air (moisture) in your confined garage can settle in your vehicle and mold can start to grow and spread rather quickly if conditions are right. The mold will start to feed on any organic material it can find in your vehicle. It usually likes leather seats and it loves dead skin cells and skin oil. That’s why steering wheels seem to get a lot of serious mold on them. Also, leaving windows open can give easy access for rodents, such as mice and rats, to chew through your under dash wires and create nests inside your vehicle.
If you decide you want to close all the windows in your vehicle, then we also suggest closing all the vents in your vehicle. Make sure you engage your recirculation button before you turn off your vehicle. This will close the air intake door vent. Keeping humid air from making its home inside your vehicle is key to keeping your vehicle mold free.
If it were my vehicle and I had to choose between keeping the windows open or closing them, I would choose to close them.
Other Considerations for Long-Term Vehicle Storage
Maintaining Your Vehicle’s Battery
No one wants to come back to their Lowcountry home only to have a vehicle that won’t start. It gets really hot in your garage during the summer months. The heat, along with your vehicle staying idle for long periods of time, can cause your battery to drain or go flat. It will then require a jump start or a charge, both of which can lower the lifespan of your battery. If left long enough, your battery will need to be replaced. So how do you avoid having issues with your battery?
- Disconnect the Battery – You may lose your dashboard and radio settings but at least your battery won’t be drained from an unknown item somewhere within your vehicle’s electrical system. It can be burdensome to have to pull out the ratchet set each time to disconnect your battery, but you can have a battery disconnect switch (some call it a “kill switch”) connected to the battery’s negative terminal. That way, all you have to do is turn it on and it disconnects the battery. Then simply turn the knob the other way and it connects the battery again. There are several different kinds of disconnect switches. You can also ask your auto repair tech which one is best suited for your vehicle.
- Connect a Vehicle Battery Maintainer to Your Battery – Please note that a battery charger and battery maintainer are NOT the same. Do not connect a battery charger to your vehicle for a long period of time, use a battery maintainer instead. A battery maintainer is a device that connects to both your negative and positive battery terminals and plugs into your garage electrical outlet. It’s essentially a trickle charger that helps the battery maintain a charge while sitting dormant. The trickle charge is enough to counteract self-discharge, but not so large that it threatens to overcharge your battery. By using a battery maintainer you’ll be able to extend the life of your battery. When properly maintained, your battery can last for more than five years. However without proper maintenance, your battery may fail in less than two years. You can get a decent battery maintainer at your local auto parts store for around $40 to $90 depending on the one you choose. Make sure you know what kind of a battery you have (Standard, AGM, Lithium, Gel) so you can purchase the appropriate battery maintainer for your vehicle.

Avoiding Long-Term Tire Flat Spots
So you get back to your Lowcountry home after being away for 6 months, you hop into your vehicle and head off to the store for some groceries. On the way to the store you feel this unnerving vibration that appears to be coming from your tires. You think, “Is my car safe to drive? Do I need to replace my tires?” Once you realize your tires have flat spots, you start asking yourself, “What could I have done to prevent this?”
Flat spots occur on your vehicle’s tires when the weight of a vehicle presses down on the same section of immobile tire for a long period of time, changing your tire’s circumference. It’s been suggested that tires nowadays can withstand flat spots much better than older tires due to technology and quality. Others suggest that is not the case. Either way, here are some easy-to-do-basic tips that could help minimize flat spots.
- Make sure the tire pressure in all 4 tires is properly filled to standard manufacturer’s recommendations and consider adding an additional 3 to 6 pounds of air pressure. Just make sure that when you drive your vehicle again that you drop the air pressure back to manufacturer’s recommendations.
- Park each tire on a piece of thick carpeting. This is so your tires don’t come into direct contact with the hot concrete.
- Consider purchasing flat-free tire supports or tire ramps and parking your vehicle on them. They can cost anywhere from $80 to $300 depending on the kind you buy. Once the tires are set on the supports they settle into the ramp’s concave depression which helps support more of the tire. This dispenses the weight of the vehicle more evenly onto the tire, helping to prevent any flat spotting.
Fuel Stabilizers
If the fuel in your vehicle will remain longer than 90 days, then consider adding a fuel stabilizer to your gas. Prior to leaving your vehicle for the summer months, add the full stabilizer with a full tank of gas and let the engine run for a few minutes to circulate the fuel stabilizer through all system components.
The fuel stabilizer helps prevent condensation forming in the tank when temperatures change. It helps prevent gasoline from oxidizing and it coats metal surfaces to prevent corrosion.
Some quality fuel stabilizers can keep fuel fresh for extended periods of up to 12 to 24 months.
Be sure to get the proper fuel stabilizer for the type of fuel you are putting in your vehicle.
Should I have Someone Inspect My Vehicle When I’m away?
Even following all the best practices, it is still not uncommon to find mold growth and other problems with your stored vehicle. Having someone within the home watch industry who is knowledgeable and trustworthy routinely inspecting your vehicle remains crucial to providing the peace of mind you deserve.
Further, it is recommended to occasionally move the car in and out of the garage, so that the weight of the car is not always resting on the same spot. This is commonly called Auto Starting Services in the Home Watch Industry. Your Home Watch Professional should be able to perform this service
There is a lot to think about when leaving a car during the hot summer months and the last thing you want is damage to your vehicle.
Make sure to discuss all of the above with your Home Watch Professional; s/he should have a deep knowledge of the issues related to storing a vehicle in a hot humid climate and should be able to explain all the different services offered by the Home Watch Company.
**Always seek advice from your vehicle’s manufacturer prior to doing anything you are not certain of.