# Finding solid ground



## bradleyheathhays (Apr 15, 2021)

I'm rehabilitating this old dirt floor garage for a work area and I'm looking for something to help level the floor up. It doesn't need to be perfectly flat or anything, just so I don't feel like I'm crossing the Grand Canyon when I'm moving things around. I'm thinking there might be something like a small gravel that's cheap and would do the job. When I helped my neighbor put his driveway in they laid down some decent size gravel called 57s. They flatten out a little with some vehicle traffic and get locked into place. I need something like that but smaller. Those were ~2" but I probably need something 1/4, maybe up to 1/2."


Any suggestions?

Reactions: Informative 1


----------



## Eric Rorabaugh (Apr 15, 2021)

Look for some #8's. Thats one that we had at the quarry I worked at. Some people call it pea gravel. 1/8"-3/8" stone. It won't really pack and lock in though


----------



## barry richardson (Apr 15, 2021)

I'm thinking decomposed granite might work pretty good....

Reactions: Like 1 | Agree 1


----------



## Mike Hill (Apr 15, 2021)

Both 57's and #8's are washed gravel (no fines) and specific sizes. To "lock in" you need a variety of sizes and some fines to fill in the voids. It's been quite a while since I've bought gravel in Lexington so don't remember what they call it but around a lot of places it's called DGA - Dense Graded Aggregate. It contains a good range of small gravel sizes and stone dust. It compacts very well because of the small sizes and upon being wetted it can somewhat harden up because of the stone dust.

Reactions: Useful 1


----------



## Mike Hill (Apr 15, 2021)

Decomposed granite would probably work also, but not widely available. I can't remember, but I think Lexington is a crushed limestone area.


----------



## woodtickgreg (Apr 15, 2021)

Around here we can get crushed concrete, they call it 21A, they use it for road beds. I usually ask for the fines.. Once it gets wet and packed down it really firm's up again. I have done an entire driveway with it and once it gets driven on its almost concrete again, lol. I also used it as a base under my patio concrete. Spread it, spray it with water and pack it down. You can use a hand tamper in the small space of a garage.


----------



## Mr. Peet (Apr 15, 2021)

Mike Hill said:


> Both 57's and #8's are washed gravel (no fines) and specific sizes. To "lock in" you need a variety of sizes and some fines to fill in the voids. It's been quite a while since I've bought gravel in Lexington so don't remember what they call it but around a lot of places it's called DGA - Dense Graded Aggregate. It contains a good range of small gravel sizes and stone dust. It compacts very well because of the small sizes and upon being wetted it can somewhat harden up because of the stone dust.


Also called "crusher run" and "modified". #8's here are 8" (state specs call it Gabion), twice as big as # 4 stone. Anti-skid is the small 3/8ths stuff here, often used as road cinder substitute. They have it washed as well for other things. Amazing how the "same" changes names as you move around.


----------



## sprucegum (Apr 16, 2021)

bradleyheathhays said:


> I'm rehabilitating this old dirt floor garage for a work area and I'm looking for something to help level the floor up. It doesn't need to be perfectly flat or anything, just so I don't feel like I'm crossing the Grand Canyon when I'm moving things around. I'm thinking there might be something like a small gravel that's cheap and would do the job. When I helped my neighbor put his driveway in they laid down some decent size gravel called 57s. They flatten out a little with some vehicle traffic and get locked into place. I need something like that but smaller. Those were ~2" but I probably need something 1/4, maybe up to 1/2."
> 
> 
> Any suggestions?


Every geographic area has different raw materials to work with and different names for the same type of material. The best material we have for what you are doing is called stay matt, it is crushed shale ledge that has been screened but not washed so the fines come with it. For driveways we use either 1/2' or 3/4" minus. 1/2" has nothing that will not pass through a 1/2" screen. They sell it all the way up to 6" minus. No matter the raw material you need the fines for compaction.

Reactions: Agree 1


----------



## Mike Hill (Apr 16, 2021)

Mr. Peet said:


> Also called "crusher run" and "modified". #8's here are 8" (state specs call it Gabion), twice as big as # 4 stone. Anti-skid is the small 3/8ths stuff here, often used as road cinder substitute. They have it washed as well for other things. Amazing how the "same" changes names as you move around.


Yeh, most plants around here call it crusher run also. Its sort of a by-product - it's largely what comes out of the sifters. But in school, when I first moved here, and in other limestone areas of the SE, it was DGA - and I stuck with the name. 4" to 8" is called Surge and 8" and bigger - shot rock. Looking over to my wall where I hang up some pricing stuff, one company has two products - pugmill base and 1/4" to dust - both would work. Pugmill is cheaper - both are technically DGA's - just different materials used for fines.


----------



## Eric Rorabaugh (Apr 16, 2021)

We had crusher run and 26's. Pretty much same thing. Our pug was crusher run with the water already mixed in. It went to road jobs so they didn't need to grade and spread water. Could go from grading straight to compacting. When it dries, like concrete


----------



## Mike1950 (Apr 16, 2021)

here it is called 3/4 minus. you also can get recycled asphalt. not sure how that would work inside

Reactions: Like 1


----------



## vegas urban lumber (Apr 16, 2021)

find an old semi trailer, remove the hardwood butcher block floor planks, install them in the garage over a thin layer of sand, then send the semi trailer to the scrap metal yard, or get the wood out of a semi trailer already at the scrap yard


----------



## bradleyheathhays (Apr 17, 2021)

Thanks for all the good idea, hard to address them all. Seems like since material varies according to the region maybe I should just call up the local quarry and ask what they'd suggest from their line. Lexington does have a crushed limestone mine right in the middle of town so I won't have far to go. I guess I should be calling both blacktop and quarry companies.

Reactions: Like 1


----------



## bradleyheathhays (Apr 22, 2021)

Here's a sample I got at the quarry. It seems to be just as much sand as rock. After it's compacted I'll have this 2-3 in thick. Is there anything I can add to it that's cheap and I can get in bulk that will help it harden with water added?


----------



## Mr. Peet (Apr 23, 2021)

bradleyheathhays said:


> Here's a sample I got at the quarry. It seems to be just as much sand as rock. After it's compacted I'll have this 2-3 in thick. Is there anything I can add to it that's cheap and I can get in bulk that will help it harden with water added?
> 
> View attachment 207748


Sand and not stone dust..?.. Some guys would buy a few bags of Portland type S or even F, and rake it into the top inch or so and let it draw moisture from the ground and air. The cement acts as a hardener and binder.

Reactions: Like 1 | Agree 2


----------



## Mike Hill (Apr 23, 2021)

What he said. Or just plain cement.

Reactions: Agree 1 | +Karma 1


----------



## bradleyheathhays (Apr 23, 2021)

You're right Peet it's stone dust. Sand is what they call it at the quarry. I think the final plan is gonna be to lay 3-4 in of stone in, add in a good amount of this on top...





Rake it in, water, rake some more and compact it down. Since regular concrete does better when you use less water I wonder if that's what I should do here too?


----------



## Mr. Peet (Apr 23, 2021)

bradleyheathhays said:


> You're right Peet it's stone dust. Sand is what they call it at the quarry. I think the final plan is gonna be to lay 3-4 in of stone in, add in a good amount of this on top...
> 
> View attachment 207776
> 
> Rake it in, water, rake some more and compact it down. Since regular concrete does better when you use less water I wonder if that's what I should do here too?


That already has sand and lime added. The Portland "S" or "F" is straight concrete...likely cheaper.


----------



## Mike Hill (Apr 23, 2021)

That is a concrete mix - therefore is a mix of cement, sand, aggregate, and possibly additives. Good stuff, but not. What I would advise. The mortars are actually mixes also. They are mixtures of cement and sand and some types also have plaster. Better use than the concrete mix, but straight cement would likely be better.. Cement is the glue that binds - so to speak. The mixes will have less cement per volume than the straight cement. And yes too much water is bad. A good dampening.


----------



## bradleyheathhays (Apr 24, 2021)

10 4. Looks like the type F Portland has microscopic fly ash so maybe that'd be the better option over the type S. Where would one go in a moderately sized city in the mid-west to find themselves such a cement? Big box and goober searches don't show anything.


----------



## 2feathers Creative Making (Apr 24, 2021)

Portland type I/II should be straight cement and give you more bang for your buck.

Reactions: Agree 1


----------



## Mr. Peet (Apr 24, 2021)

bradleyheathhays said:


> 10 4. Looks like the type F Portland has microscopic fly ash so maybe that'd be the better option over the type S. Where would one go in a moderately sized city in the mid-west to find themselves such a cement? Big box and goober searches don't show anything.


Anywhere they sell "real" masonry supplies. Lowes and Home DePot often have it in small amounts, but block suppliers tend to have plenty. Worst case, ask a local builder or mason for direction.

Reactions: Agree 1


----------



## Mike Hill (Apr 24, 2021)

Often it is called Portland cement. Just googled HD and they have it. Most lumber yards also have it. At least around here as well as contractor and masonry supply houses, brick yards and block suppliers. I bet you'd find it at good hardware stores too. A percentage of Fly ash is ok. Most ready mix plants use it - it's cheaper than cement but it adds a slipperiness to the mix that makes it easier for the finishers. Most masons, especially commercial ones will buy pallets of Portland's and tons of sand and mix their own mortar.


----------



## bradleyheathhays (May 10, 2021)

Well I finally got it all together. So far I've got 6000 lbs of 1/4" and below limestone 'fines' shoveled into my 24x24 ft garage and have the last 3000 lbs on the trailer backed in and ready to offload. Plan is to rake it all out then add about 1000 lbs of portland cement type I / II over the top, rake that in good, mash down with a plate compactor then sprinkle some water on. Never done this before but if I can pull it off I think it can turn out to be a real decent floor.

One problem is the current rock / dirt floor is sloped, with some mild lumps in the middle. Right now the rock that's down is in piles and most of those lump areas are still exposed, so I wonder if I should compact those lumps before spreading the rock on. Sounds like a good idea to me.

Biggest issue is that one end of the floor is 4-5" lower than the other, so my rock will need to be 2" after being compacted on the high side and 6-7" compacted on the other. I've used a laser transit to mark good level lines down close to the floor and I'll be able to run string all across so I'll be able to gauge rock depth / level / slope fairly accurately before compacting.

Questions..

I'm guessing I should rake the rock out so that before being compressed it's level higher on the end that needs to be thicker. Wonder how much higher?

How much is this stuff gonna compact?

How much water should I add after it's all pressed down?


----------



## Alan R McDaniel Jr (May 10, 2021)

Cement by itself will harden but it will also crack and will not wear well. It really needs to be mixed thoroughly with sand to cure correctly. In the past I have done what you are thinking of except with pavers and broken concrete. I used quickcrete mortar mix and regular quickcrete mix. I filled in the spaces between and watered it. I did not allow the water to run across the top of the pavers but kept watering until the mix was saturated. 

Straight cement will make a lot of dust as you walk, drive or work on it. It is not intended to be used by itself except in cementing operations on drilling rigs.

Alan


----------



## Mike Hill (May 11, 2021)

Did you say how many square feet you are doing? oh, I see now - 24' x 24' (edited)


----------



## Mike Hill (May 11, 2021)

If you are using 9000# of limestone in a 24 x 24 space you are putting in an average of about 2". This assumes a unit weight of the mix of about 2500 LB per CY. If you have the space, I'd put more in. As close to 4" minimum as you can. If a minimum 4" and an average of 6.5" because of the unlevel ground, they you would need about 14 to 15 tons of limestone. 

Compact the existing ground as good as you can. The best place to start is a solid base!

The compaction will vary depending on conditions. I'd put in about 2" then compact, add 2 more inches and compact. That way you'll have compaction the entire thickness - not just the top inch or so. But for a guess for the light compaction that you are going to utilize and since the voids are thereotically filled up with fines, compaction will be on the light side - maybe 5% up to possibly 10%. 

What you are essentially doing is doing a rudimentary (weak) on-site mixed concrete topping on top of base. The 1/4" and below will "set up" by itself to some degree. The addition of the cement should help this happen better. What cement does is upon being hydrated, each particle of cement starts forming itself into a gel-like substance that sticks to all the other particles in the mix and glues it all together. What will be important is not to water heavily, but sprinkle lightly. Watering too fast will wash out the cement and the fines - ask anyone who does concrete what a hard rain will do to a slab pour. I'd rake in the cement then compact lightly and quickly -then sprinkle the initial water - and compact again to bring some fines to the surface and embedding the loose stones the best you can. The limestone mix is likely wet (usually is because stored in piles and rained on - so wetter sometimes that other times) so the cement will start curing as soon as you mix it with the limestone. It won't flash set on you, so you have time, but don't leave it overnight before you add the water. 

Oh, concrete does not harden by drying. It hardens by curing. The cement particles have to hydrate and then go through a chemical process to harden. After about 36 hours, most of the hydration process is complete, but the cement will continue to cure as long as water and unhydrated compounds are present. So would be best to keep the floor damp for about a week. Keep it sprinkled ocassionally to keep it from drying out. Alternately is to use a curing compound after the surface water evaporates. It sprays on with a simple pump sprayer. 

An average 1:2:3 concrete mix contains one part cement, two parts sand and three parts gravel. The amount of water you use depends on how wet the limestone mix is. If it's already moist, you'll need about 4-1/2 gal. per 94# bag of cement. With 1000# of cement, you have about 10 94# bags of cement - therefore about 45 gals roughly. 

This will not result in a perfectly smooth floor like your house may have, but should give you a reasonably servicable surface. There will likely be much exposed aggregate, loose stones and dust. Sweeping can take care of it, but you can also put on additional coats of a concrete sealer sprayed on with a pump sprayer to keep the dust down.

Reactions: Like 1


----------



## Mike1950 (May 11, 2021)

little over 7 yards of concrete would do that floor 4" thick. Then you would have a real floor. doing a base and thin concrete shell over it will be like an eggshell. do not drive car on it..... or real heavy equipment. Cement and gypsum plaster was my game for 35 years...


----------



## bradleyheathhays (May 11, 2021)

Alan, Mike and Mike, thank you!

I'm hoping the fines in the limestone mixture will act as the sand part of the normal concrete mixture.

In the end I know this won't be as good as a poured concrete floor like I'd rather have, but it's only intended to be a shop floor that'll be cared for when moving equipment and will never have a car parked on it. Sounds like if I spray with a sealer after everything is cured as Mike Hill suggests then I'll have a reasonably well functioning and dust free shop floor. It's been a long time coming and I'm so ready.


----------



## Alan R McDaniel Jr (May 11, 2021)

When I lived at our ranch in South Texas, we had a big driveway covered with caliche. Caliche is basically limestone. This particular limestone can be crushed to a powder and over time will turn into a powder if driven on repeatedly. It is used all over South Texas as road base and county road topping. 

For 100 years (literally, since 1903. We lived there from 75-89), every drop of burnt oil or other waste petroleum products were poured out over that driveway. When I was there I used a sprayer to put it out. It kept the dust down and as an added benefit, turned the driveway into a sort of asphalt like surface.

Countless wagon wheels, truck and car tires and horse and cattle hooves compacted it. It's still hard as ever.

Alan

Reactions: Like 1


----------



## bradleyheathhays (May 16, 2021)

I really don't know if I would have chosen to do this if I would've known exactly how much effort this was gonna take. In for a penny in for a pound I guess. So I got my 20x 47lb bags of type I/II portland cement evenly distributed (1 bag per ~18 sq ft, about 390 total) and raked into the top 2-3 inches of the 1/4" and below limestone fines. Rented the smallest plate compactor, 13" model and when I ran it over the mixture it basically cut huge tracks vibrating down _through_ the rock spitting it out from the sides of the plate. I think the problem is the added cement powder has made for a fairly slippery mixture, something that a larger rock substrate might not suffer from. Giving it a second try I ran the compactor at it's lowest speed and although it was more manageable it basically did the same thing. The machine did manage to leave some of it compacted so I know it can work, just not this way. Good news is the compacted stuff looked filled in with almost no gaps so that bodes well for it setting up proper.

This was the scene after I got to the end of the first row, approaching from the left, and tried to pivot...





My only ideas left is to either use a 8x8 tamper or some kind of weighted roller. I've been a glutton for punishment for this whole project so hand tamping out a smooth floor will be worth it just to get it done. 

Any ideas on how to compact this floor without using a compactor?


----------



## Mr. Peet (May 16, 2021)

Well, the compator was to be used before putting down the Portland, to firm up the leveled base. Or if to had layered, stone then portland topped with stone, tamping after each stone layer (often lightly wettung the stone to reduce dust). Then the the Portland raked out or broomed onto the the wet stone base. Never seen anyone tamp the cement layer...

So at this point, you could broom it off to the side and run the compactor. You might be able to wet the stone and wash the dust in before doing it..?.. Then after compact, spread the Portland back out, broom it in and dampen down...


----------

