Garage Humidity is Destroying Your Tools and Electronics

I think everyone can agree that humidity makes us miserable. Heat is bad enough, but the humidity makes everything unbearable.

But how bad is it for the stuff you store in your garage?

As it turns out,…pretty bad.

Your garage is home to your tools, personal items, exercise equipment, toys, and (of course) your car. Humidity can be very damaging to all of those items – especially electronics.  

Tools and vehicles constantly exposed to high humidity levels can risk rust. Electronics, even those that are water-resistant, can be damaged by high humidity levels in your garage.

In addition, personal items can be damaged or even destroyed by humidity if not stored in air-tight containers. Papers, cardboard moving boxes, and fabrics are easy targets for mold and mildew.

This article will get a little sciencey because it’s vital to show that this isn’t just my opinion, and there are facts to back it up.

If you don’t care about the science, please skip down to the “Summary” section to see the summary and some recommendations.

But if you’re still on board, let’s keep going.

Humidity is Terrible for Your Tools

Water and metal don’t mix. Got it. We’ve all seen rusty steel tools before, so this shouldn’t be a surprise.

Fair point, but hang on a second because it’s worse than you think…

Did you know that stainless steel can rust?

I didn’t.

Stainless steel isn’t pure steel but a mixture of several metals. Some, like Chromium, help make the resulting metal resistant to rust.

It’s not entirely rust-proof, however.

Cougartron, which is a US-based company that makes stainless steel coatings, sets the record straight:

The reality is that stainless steel does rust. The word “stain-less” does not imply free from stain or “stain-impossible.” It simply means that the alloy stains less.

Given the right set of circumstances, any metal can rust or corrode. It’s essential to keep moisture and humidity under control to prevent your tools from rusting in your garage.

Is Humidity Bad for Electronics?

This makes sense, right? Water and electricity don’t mix.

When I say “electronics,” I mean anything with circuitry or wiring.

So this would include big things like your garage TV, a sound system or speakers that you keep in your garage, or any exercise equipment you store or use there.

It also includes any power tools or your classic car sitting under a car cover in your garage.

Now, do I have your attention?

The challenge is that even electronics that are designed to be water-resistant are still exposed to the air. If humid air can get in, it can bring water vapor.

Water-resistant and water-vapor resistant are NOT the same things.

When water vapor in the air cools down, it changes into a liquid. This is how we get dew on the grass in the morning or frost in the winter.

Semikron, one of the world’s largest semiconductor manufacturers, released a study on the effects of humidity and condensation on electronics back in 2016.

They found that condensation poses a severe threat to electronics because the water molecules are attracted to the electrically-charged circuits inside the devices.

As they put it: “the resulting failures from these effects are usually catastrophic, and it can be very difficult to identify humidity as the root cause.”

In this case, an ounce of prevention is worth more than a pound of cure.

Condensation Breaks Down Lubrication

We’ve all heard the saying that oil and water don’t mix. That also applies to any lubricants you may be using in your garage.

One key element in maintaining our tools and lawn mowers is lubricating any moving parts with oil.

When water vapor (in the form of humid air) condenses and turns into liquid water, it eventually starts to break down any oils it comes into contact with.

We all know how destructive it can be when sand or metal shavings get into your gearbox.

Consider what J. C. Fitch and Simeon Jaggernauth said in their paper on the effects of moisture on machinery:

“Moisture is generally referred to as a chemical contaminant when suspended in lubricating oils. Its destructive effects in bearing applications can reach or exceed that of particle contamination.”

According to their study, moisture can be as damaging – or MORE DAMAGING – than any physical particle rattling around in your gearbox.

Summary (for those that skipped ahead)

So we learned that a high amount of water vapor in the air is the same as a high relative humidity level. That water vapor will eventually condense back into liquid water and start destroying our tools, electronics, and any lubricants we use on our machinery and tools.

So what do we do about it?

High humidity in your garage
This is far too much humidity in your garage

The obvious lesson here is to try to control the humidity level in your garage.

Here are seven tips that I recommend:

1. Use a Dehumidifier

This is the most effective (and cheapest) option. Most dehumidifiers are less than $200 and can lower the humidity level in your garage and keep it there.

Check out my detailed article for my recommendation on what I consider the best garage dehumidifier.

2. Moisture absorbers are quick fixes

A lower-cost option would be to use a moisture absorber like Damprid.

They only last around 45 days, so they’re not a long-term solution. However, they’re a great option if you only have a few high-humidity days each year.

3. Seal your garage door and windows

Try to make your garage as air-tight and water-tight as possible.

This means replacing any damaged seals around windows (if you have them) and your garage door.

Also, look at a garage door threshold seal to act as a water barrier and keep moisture out of your garage.

4. Increase air flow with a fan

Any airflow in your garage will help spread the humid air to other parts of the room. It’s not a perfect solution since it still relies on that air going somewhere.

If the entire garage is filled with humid air, moving it about won’t help.

But the thought is that a good garage fan circulating the air towards an open window or exhaust fan will help lower the overall humidity in the room. I use a wall-mounted Air King fan and it works great.

5. Seal your concrete floor

Did you know concrete sweats?

Concrete is a very porous substance, meaning it absorbs water exceptionally well.

Unfortunately, that works both ways. When you see beads of water on the surface of your concrete floor, that’s called concrete sweating.

A great way to fix this (and stop that moisture from evaporating into the air) is to seal or epoxy your bare concrete floor.

6. Waterproof your concrete walls

If you have bare cinder block walls, it’s good to paint them with water-repelling paint.

I used Drylok to waterproof my concrete garage walls to add an extra layer of protection and keep any moisture outside where it belongs.

7. Air conditioning

The best solution is (of course) the most expensive. Installing an air conditioner in your garage will help keep the relative humidity level low.

Portable air conditioners start at around $300 and go up to about $1,000 for a mini-split air conditioner.

Wrapping It Up

As I said initially, humidity can be catastrophic, especially if you try to store things in a damp garage.

When relative humidity levels stay over 50% for extended periods, it becomes a breeding ground for mold and mildew. Condensation can form on your metal tools and inside your electronic components.

Eventually, that moisture damages everything it touches, so it’s good to take precautions and lower the humidity levels in our garages.

Photo of author

Tim Wells

Tim Wells, the founder of Garage Transformed, has been featured in dozens of home renovation publications, including, Home Stratosphere, House Digest, Livingetc, and SFGate. Since 2018, he has helped over two million people transform their everyday garages into something they can be proud of. He lives in Central Florida with his wife and bulldog.