"floor" for garage

[N1ST]

I'm putting up a shelter logic fabric garage soon, and think I'd like to dig up the grass, put down a plastic vapor barrier, then crushed rock on top of it. the goal is to keep the humidity down inside, and also provide some type of floor.

With my 4' FEL, would it be easier to try to skim the sod off or would it be easier to til it first?

What type of crushed rock, clay, etc. should I use and how many inches?

Thanks.

 

[joe48]

I'm putting up a shelter logic fabric garage soon, and think I'd like to dig up the grass, put down a plastic vapor barrier, then crushed rock on top of it. the goal is to keep the humidity down inside, and also provide some type of floor.

With my 4' FEL, would it be easier to try to skim the sod off or would it be easier to til it first?

What type of crushed rock, clay, etc. should I use and how many inches?

Thanks.

If you want to remove the dirt and sod and have the tiller, then thats easy. Set the tiller for the depth you want, till it twice with an overlap pattern, then use your bucket w/o teeth. It will skim the loose dirt off the under layer with slow and careful control of bucket angle (dead flat).
lay in your vapor barrier and top with either crusher run with dust for a more permanent hard surface when packed or if ease of removal later use what is know as B 1 B crush, which is a small (under 1/4", bigger than 1/8") stone, washed and uniform in size , packs nice but easily worked with hand tools and easy to remove later if needed. ( commonly used under paver blocks by pros)

 

[EddieWalker]

Humidity isn't determined by the type of flooring you have. It's all about mosture content in the air and the tempature of the air. If you want to control the humidity, you need to insulate and heat/cool it. Ventalation with fans is also fairly effective at cutting down on the amount of condensation that comes with humidity in a shop or barn. In metal buildings, it can feel like rain at times when it's really bad, but the floor type doesn't have anything to do with this. It's all about the water in the air.

If you just want some sort of flooring, gravel is terrible. I'd go with old fashined compacted smooth dirt before I used gravel again. Then in time, pour concrete. If you have limited funds like the rest of us, consider pouring the concrete in sections. You have so much set aside for gravel, so use that amount for a cement pad where you will need it first. Then, when you have more money, do another pad.

Eddie

 

[joe48]

The movement of MOISTURE from the ground to the air inside the enclosure is a legitimate concern regardless of outside air humidity. However air circulation is important to lessen the effects of condensation from humidity as temperatures change.
I have used both tarps and vapor barrier plastic in my shelters. If parking equipment just drive it in and park, if storing other types of equipment or parts etc I usually put them up on pallets so not in contact with ground or tarp and allows air circulation all around.

 

[Builder]

The movement of MOISTURE from the ground to the air inside the enclosure is a legitimate concern regardless of outside air humidity. However air circulation is important to lessen the effects of condensation from humidity as temperatures change.
I have used both tarps and vapor barrier plastic in my shelters. If parking equipment just drive it in and park, if storing other types of equipment or parts etc I usually put them up on pallets so not in contact with ground or tarp and allows air circulation all around.

I tend to agree, especially if your equipment is not used frequently.. Have you ever noticed that equipment parked over grass quickly gathers moisture and will begin to rust even out in the open air. I think "drying out" the ground below it can only hep the bottom of your equipment from wicking up moisture underneath.

Quick story: Years ago, I was going to buy a really nice low mileage F-350 4x4. It was reasonably priced and only had ~8,000 miles on it. I couldn't understand why I drove past it for like a year and noone bought it! Finally I stopped by to test drive it. It was sitting parked on a lawn in front of a business along the road. I was amazed to see how much rust had formed on the frame, axles, etc. under the truck. The owner informed me that the truck was parked over grass most of its' life and combined with low useage, the frame had gathered a lot more rust than a vehicle parked over a dry surface and driven a lot.

 

[LarryRB]

Don't know where in CT you live, around this northeast area, most use Amrec,, This is a combination of asphalt millings, broken up concrete Jersey barriers, 1/2 " stone, and on ocassion you will find new shingles that didn't make the grade, ground up and all this concoction has binder put in., I have most of my 1600 ft driveway in Amrec, most municipalities Ct and lower Massachusetts use Amrec to go over gravel and or dirt roads. Once a rain hits it, it binds right up tight and is hard as concrete.

 

[patrick_g]

The movement of MOISTURE from the ground to the air inside the enclosure is a legitimate concern regardless of outside air humidity. However air circulation is important to lessen the effects of condensation from humidity as temperatures change.

It is with some trepidation that I contradict Eddie but I think the above says it well. Ground evaporation and transpiration of the grass contribute to humidity and in an enclosed space will raise it considerably.

Now for my question... Why go to the effort to work the dirt first? If you are putting a good quality vapor barrier down over the grass and a decent thickness of gravel over that then why bother removing the grass. It will die and NOT be a problem.

A larger problem will be if you use sharp edged gravel and don't put it deep enough to "randomize" the loading from vehicular tires. If you don't want a THICK layer then put down some sand first or fine chat and then top with gravel. This will reduce the punching of holes in the vapor barrier.

In similar situations some folks have used pressure treat or landscaping poles or ... to form a low wall to retain the gravel inside the desired area.

If sometime in the future (and who can say for sure when or if) you want to remove or move the "floor" you can do so using the above methods. It will be easy and not require a lot of filling and leveling. Just move the "shelter building" and its floor and then stirr the dirt a bit and reseed.

Another question might be: Why not go extra HD on the vapor barrier and skip the gravel? You can use sand or kitty litter or diatomaceous earth under leaks. IF slipery is a consideration put on a layer of sand.

Pat

 

[Lynkage]

These all are good answers.
Here is another possibility for you. Use recycled asphalt. You could use a vapor barrier if you wanted but would not be required. The asphalt would provide a non-permeable base if used at 6" thick and out here in Colorado it runs about $5 a ton.

 

[EddieWalker]

I realize that most people don't agree with me on my denial that mosture is coming up through concrete floors. I also don't mind being in the minority on this. It's really a simple thing for me.

If moisture will travle uphill against gravity, through several inches of concrete, then it should do the same in the other direction with the aid of gravity. Test it out, it will never happen.

Why is it that moisture only travels up through the floors of shops and barns, but not in your house? Most every house has openings around there tub and shower dain lines. It's common to leave those openings open. If you take out your tub, you will usually see the dirt around the open space of the drain. The rest of the lines throught the concrete should leak to some small degree. I know they wouldn't be considered water proof when you put a pipe through the slab and pour around it in any pond or lake situation.

If moisture is coming up through solid concrete in a shop, why doesn't it come up through the open spaces inside your house?

As for parking over grass, I think what's happening is the humidity levels are traped under the vehicle and creating condensation on the bottom of the vehicle. More moisture on the grass means higher levels of condensation will form. Over time, this will lead to the rust, because it's never ending.

Has this ever happened to a vehicle parked in a shop/barn with a dirt floor? From what little I know, there have been thousands of tractors and vehicles parked on dirt floors over the decades. Does anybody know of any increase in rust on the bottoms of them? If moisture was traveling up through concrete, those dried out, dirt floors should be letting all sort of moisture through them!!!!!!

I guess that's another point. How do those floors get so dry and hard if there is all that moisture in the ground coming up through them? While I'm at it, has anybody ever been under a pier and beam house? The dirt in those crawl spaces is as dry as it can possibly be. You need to use an electric jack hammer just to dig in it, it's so hard and dry. Why does anybody think moisture is coming up through solid concrete, when the ground under every single building ever built is so much dryer then the surrounding soil?

The mystery has me totally confused.

Eddie

 

[Lasgambler]

When I lived in Louisana we had to put a vapor barrier under all residential slabs. My home in Slidell did not have a barrier under the open carport slab and was almost always wet.
When I lived in Sequim, WA. we built a professional office building w/o a vapor barrier, when the spaces were occupied they used the plastic floor mats behind the desk, the type to make chairs roll easier on carpet. Very soon after they realized the carpet was wet under the mats. IMHO Heating spaces w/o vapor barriers does cause moisture to come up through slabs, I have seen it happen. Just my 2 cents.