As i am moving to my house i have four cars to store in the garage. The garage only has a gravel floor for now since i threw all my money at the house, i was told gravel is the WORST to store a car on. What should i do to prevent the moisture from eating up my beautiful cars?? They all have new exhaust and im sure that will be the first thing to rust! Please any suggestion is appreciated!!!

 

I might consider a fan to blow to keep air circulating in the garage...

The problem with Gravel, sand & dirt is they absorb moisture... That sounds like a good thing, unfortunately because it absorbs it, in return it also releases it really slowly.

The down side to a fan is it may stir up dirt & dust and you may find yourself cleaning more often, BUT that may be offset by saving your car from rusting...

Personally I keep a box fan in my barn (has a concrete floor) that blows under my cars all winter long... The only places I was getting any evidence of rust was on the brake rotors, so I know that it is effecting other parts of the car. When I let the fan run all winter long on low I do not even get the rotor rust... Technically I get more rust on my rotors from a single car wash, but every bit helps when trying to store a car...

Another thing you can consider is getting the heaviest visqueen (sp) plastic sheet from Home depot, you get it in the painting department... Put it on the floor and park your car on that for the winter... I would not recommend it for cars that you are going to drive all the time as it will not hold up with heavy traffic, but it should block moisture for a winter storage. Add a fan on top of that and it should be better than nothing...



John

 

I agree 100%. Use plastic or a "Car Pad" under your cars to keep the moisture from getting to the bottom of the cars. The fan also sounds like a great idea!

Leonard

 

Thank you those are great ideas i will definitely do that, i guess the biggest thing is to keep the air moving and not let the moisture sit and do its dirty work!

 

What is REALLY interesting is I got my Auto Restorer magazine Friday when I got home... Basically they were talking about this exact thing... In short what happens is the bottom of the car is prone to condensation due to stagnent air on a cooler surface when the car temperature is around the dew point...

I will see if I can get a copy for our website.

John

 

Adding a fan to a sealed garage only moves the humid air around. It will do little to reduce it. The air needs to be actually modified. Adding a method of air exchange will help greatly. It could be as simple as an open window, attic vents, soffit vents, etc. The important thing is the air needs to enter somewhere and exist somewhere.
Surprisingly, the worst place to store a car is in an insulated sealed garage without control measures (like air circulation or dehumidifiers, etc). A heated garage with gas heated will help send some of the humidity out the chimeny, but you still need air exchange or dehumidifieing. In cases like this, an uninsulated drafty garage is actually better than a sealed one.

The second way to control humidity is by controlling it's source. The plastic idea sounds good. But be sure to seal it well all the way around the inside permimeter walls. Use a fairly heavy poly to prevent easy rips and damage. You may need to lay down protective walkways (plywood, etc) to prevent the stones from puncturing the plastic. Getting the cars in without damaging the plastic may be a little challenging. Also be sure to overlap the plastic when another row is laid down and to seal the overlap with caulking.

Even with the plastic, it's still important to try to dehumidify or exchange the air.

Good luck.

 

I know from personal experience that on a 95% humidity day that if the car is sitting outside it can be dry, top and bottom. But move the car into a barn or garage where the car is cold in the morning and as the air in the garage warms up the water wants to condensate on the car when the temp is above the dew point. Even if the humidity is 20% or lower...

Most buildings are not 100% sealed, if you have a large garage door there probably is some leakage around the edges or in between the panels.

To help with condensation, you are correct moving air, BUT even "dry air" can still have enough moisture to cause condensation. A Fan on low helps tons, like I stated before... When I started using a fan on low to simply blow under my cars the rust on my rotors went away...

John

 

well im gonna try the fan and plastic so i guess i will find out with winter soon approaching. I always thought winter was a much dryer time less humidity? oh well we will see

 

Ventilation and/or air exchange is key. Air movement is part of this equation. Dealing with the storage factors you're involved in is extremely prevalent in the construction industry here in my area (western Canada). While attaining 100% seal is not likely (or ever expected) it also not wanted (due to the conditions and situation you describe). But it doesn't need to be a complete seal, just enough to trap and maintain a level of humidity to create the situation described above.

One important question. Is your garage to be used only for storing vehicles, or will there also be a vehicle(s) entering & exiting as well? If your in a location where ice and snow can accumulate on a vehicle, that will also dramatically increase the humidity levels in your garage when it enters.

Good luck. We all hope that when we store a vehicle, we're actually doing it a benefit not a disservice.

 

Thank you, the garage in the winter will solely be a "hibernation" den for them. I live in north east ohio and winters here can be a little rough. I dont plan on opening the actual garage door until spring, although the man door will be used. Thanks i want them looking good before and after i put them in there!!

 

Best bet is an insulated garage that is not air tight (open window, leakage spots around the garage doors etc). The insulation keeps the temperature above dew point while the fresh air provides a source of low dew point air.

The reason the ground has more humidity is
a) water is heavier than air
b) the ground is colder and colder air can hold less moisture than hot air, hence the humidity percentage goes up

A winter garage that has 35°F/60% humidity will have the same dew point (23°F) as Phoenix Arizona in the middle of summertime. Phoenix = 115°F, 4% humidity, dew point 23°F. A dew point of 23° is very dry.

The key is to warm up the garage (preferably with insulation, but a heater of some sort will work too) and then keep it dry by letting cold outside air in.

If you're stuck with a gravel floor, just do the already recommended heavy duty plastic sheet under the car and try and keep the space warm but not air tight.

I wouldn't worry about driving another car in that has snow on it or is wet. Remember, when you open the garage door up to drive the other car in, you're also letting in a whole bunch of colder drier air at the same time.

 

Thank you for all the help here i really do appreciate the suggestions!!

 

My 68 is kept in my garage which is under the house. It has a cement floor but no windows. I was getting mildew on the vinyl due to the humidity in the summer. Getting a $90 de-humidifier from Walmart solved the problem. There is no cheaper, more efficient way to remove the humidity. Try it!

 

A Humidex will remove the moisture while using 40 watts of electricity. A dehumidifier runs around 800 watts. The Humidex works great for keeping the entire house dry during the wintertime as well.

 

I should mention that anyone considering a Dehumidifier that uses Freon... IIRC R12 (really old) or 134A will not work below about 40°F as the freon evaporation point is about 40°F... It works on the same principal as your A/C, once you go below a set temperature it no longer works...

One of the up sides is the Dehumidifier should turn off below that set temp, and then turn back on when it goes above that temp which should help... I am not sure if it will, I would read your instruction manual and it may vary from model to model.

John

 

Just about every dehumidifier on the market uses R-22. Once they get below about 65°, they'll ice up and not work very well. Spend all their time (and electricity) defrosting the coils, only to ice up yet again.