Heated garages... bad for cars?

**brettS4** · 02-02-2018, 01:10 PM

I recently had a conversation with a coworker wherein he told me that heated garages are really bad for cars that see a lot of snow. The problem being that the cars accumulate a lot of road salt along with the snow and ice. When they get parked in a heated garage, the snow/ice melts and wets the road salt. Over time it causes corrosion issues. I've never had a heated garage, so I have no idea if this is true, but it makes sense to me. Thoughts?

**LSNAutoDetailing** · 02-02-2018, 01:56 PM

My thought would be that if it’s cold and snowy moisture will get in and have a sauna effect.

Not to mention, seems like a waste of money/energy.

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**Mantilgh** · 02-02-2018, 02:04 PM

I believe so to some extent.

Chemical reactions are excelerated at warmer temperatures, and likewise slowed down at cooler temps.

It the water stays in a frozen state then not much really happens.

**davidc** · 02-02-2018, 05:24 PM

A guy in Vermont told me the same thing. Hard to argue the point staring at an immaculate 80's Suburban.

Dave

**WillSports3** · 02-02-2018, 06:31 PM

Well the reason for that is because salt on its on will not react with your cars metal, it needs water. So a heated garage that lets the ice melt and become water causes any salt to do it's damages, that's where the issue comes from. When it's below freezing, a lot of the water freezes and does not add anything to react to the salt. Realistically though, heated garages aren't an issue since they let the water drain away and evaporate faster. If your car sees a lot of snow, your car should be rust proofed, that should be Number 1. However some things to consider..

Water with salt in it won't freeze. That's why they use salt on the roads.
Water in a heated garage will evaporate, therefore leaving you with dried salt everywhere, as opposed to a mixture of salty slush on your under carriage.
Ideally, your car should have its undercoat sprayed with something to help protect it, that'll do a lot more than just heated vs. non-heated garages.
The cold will slow down chemical reactions. However, salt needs water to react. Having the car outside only prevents more water from getting on it, but it won't stop the existing salt and slush from reacting with metal.

**chet31** · 02-02-2018, 09:52 PM

Interesting topic, I get the logic of keeping the car cold. However, since you are bringing it into an unheated garage, engine heat is going to keep at least the front of the car warm enough to melt snow for a while. I think I'd rather have a heated garage, melt and dry everything off each night. Around here, the streets are cleared pretty well, a few days after a snowstorm, the roads are clear and dry, you can then go days without getting any additional snow or ice on your car. Plus I think there is less wear and tear on an engine that starts at 45 degrees versus 10 degrees.

**Trip** · 02-03-2018, 12:57 AM

I usually only run the heat if I am washing the car in the driveway or a water less wash in the garage. I have always been under the same impression never run heat if the car is covered with snow and ice and salt. Nothing beats being able to dry a wet car when it’s cold out with a warm garage.

**vobro** · 02-03-2018, 08:41 AM

My garage is set to 52, which is all I need in the winter. I also keep my boat with the trailer in there and have seen no signs of rust in the winter which I did see evidence off while storing in a unheathed garage. Once the concrete gets to 52 it'll keep the entire garage warm,condensation free and safe from any ice.

As far as a waste of money or energy, it costs me about $20 a month to heat a 800 sq ft garage. It's amazing how a seemingly low temp of 52 seems extra warm on a day when it's 0 out. How much money/ energy is wasted letting 3 cars warm up/idle for 15 minutes every day?

**Setec Astronomy** · 02-03-2018, 08:54 AM

Originally Posted by Mantilgh

I believe so to some extent.

Chemical reactions are excelerated at warmer temperatures, and likewise slowed down at cooler temps.

It the water stays in a frozen state then not much really happens.

This was always the conventional wisdom, that a warmer garage would cause more corrosion for the reasons you state. However, as has been stated in other posts, salt lowers the freezing point of water, so regular sodium chloride is going to result in liquid water perhaps even in a 15 or 20F garage, and I understand the mag chloride they are using around here as a pre-treatment is even lower.

So my conclusion would be that yes, a heated garage is going to be worse for the reasons you mention, but an unheated garage may not prevent corrosion for the reasons I've mentioned.

**TTQ B4U** · 02-03-2018, 09:21 AM

I disagree. Maybe if you have a POS or very old car that you don't care for. However, today's cars are so well made and the metals are coated or manufactured to be so rust resistant that it's a moot point. Cars I see with rust or rust issues are usually more than a decade old, abused and not taken care of much at all.

Our van has been in a heated garage it's entire life and it's 11yrs of Ohio Abuse under the watch of my wife havne't hurt it yet. I care for it but no where near like I do my own car as time is a constraint. ZERO rust or salt/environmental issues with it. I just had it up on a lift too and am very impressed.

I keep our garage between 60-65 most days even when it's below zero. Good insulation is key. Costs to do it are minimal and if anything it helps our master bedroom that is 24x24 located right above my garage.