Compacting dirt floors in a shop..?

[RKM556]

Hey everyone! 

 

So I love my shop. I honestly do. I mean, it could be expanded someday but for now it's the perfect size for me. However, there's one thing I wish I could change if possible. My floor is dirt, which is totally fine, except for the fact that it gets dust on EVERYTHING. Half of my electric tools are my great-grandfather's and I would prefer to keep them clean (and everything else in my shop) without having to dust it all down all the time, ect. Do you guys know of any way to compact a dirt floor to make it a bit more solid so the dust stays on the ground? Concrete is not an option because, well, its expensive. If there's no solution, that's totally cool, but I just wanted to see what there is to know.

 

Thanks so much!

 

Ryan

[Steve Sells]

rent a compactor for an afternoon.

[Chinobi]

How loose is it right now? You can compact with as little as a stone dropped from a few feet up or move your equipment out and rent a thumper for the day. If it's really deep and loose you could even need to over-excavate as you can't effectively compact thick layers in one shot, especially with hand/man portable tools (soil type will heavily influence as well)
If you just want dust control you could spread a layer of gravel over the top instead of concrete (gravel isn't exactly cheap either though)

[ThomasPowers]

Oxblood was a traditional method....how much clay is in your soil?

[Frosty]

Compacting and dust control is more about gradation than compaction. Gradation is the mix of material size in the mix. You need enough fines to fill all the voids and bind it together. You also need angular material to key together and form a solid grade. If the soils are river deposits (alluvial) round particles it will shift no matter how much you run a compactor over it. Think a bag of marbles for a picture of what's happening. Angular means it's broken in a crusher or by natural process. Natural angular material is a lot harder to come by. The industry standard sub base is D-1 which is 3/4" minus crushed or 3/4" minus Crusher run. Depending on who you're ordering it from but all the aggregate or gravel plant guys will know what you're asking for.

 

Lay it in 4" lifts if you're using a plate compactor or it won't compact all the way through. If' you're using a jumping jack compactor you can go as much as 12" lifts but not as a final finish coarse. The terminology here is counter intuitive but industry standard. BASE courses are lower in the grade, SUB BASE are right under the FINISH course. The FINISH course is right under the PAVEMENT or it's what you Walk on. this is the grade, from top down you walk or pave on the FINISH course which is on top of the SUB BASE course which is on top of the BASE course which is on top of the FILL courses. A course is a LAYER placed by the contractor to make a competent grade which is what you drive or build on.

 

Not knowing what your base and sub base are I can NOT make specific recommendations so I need some input from you before I can be more helpful.

 

Just so you know, I worked for the State Of Alaska as a lab tech before transferring to the drilling section of the Foundations section of the Geology Department of Head Quarters Materials. All that jive means I have first hand knowledge and experience with the design guys for road grades and bridge foundations design and construction. I am NO highways or foundations engineer but I can help you design a good solid shop floor or foundation from a practical, hands on level.

 

Frosty The Lucky.

[Glenn]

Depending on the material you have now, add some cement and mix it up, then compact. The cement will harden with the native material and lock it in place.  This is not a thin layer but thick enough to support itself under the load you have in the shop.

 

Drainage is always put in place UNDER any floor material to remove the water.

 

Go with the old method of 4 to 6 inch wood stack end grain up. Build a drainage system, a good base and sub base, then the wood. It has worked for years in many a blacksmith shop.

[DSW]

Depending on the material you have now, add some cement and mix it up, then compact. The cement will harden with the native material and lock it in place.  This is not a thin layer but thick enough to support itself under the load you have in the shop.

 

 

That's what we did in my bosses horse barn to keep the horses from digging holes in the dirt floor. We managed to get some nice clean clay and rototilled it in well with a bit of portland cement into the existing dirt floor. Then we lightly sprayed the floor with water and continused to rototill it in. You want the floor damp, but not muddy. Rake it out and then you cpmpact with a plate tamper if you want a smooth floor. Right now you couldn't dig in that floor with a shovel and a pick just chips out small pieces. ( PITA when you have to did out rotted stall posts)

 

 

Other options are crushed concrete, asphalt road millings, and "modified" which is a mixure of 3/4" stone down to stone dust. Modified and crushed concrete pack and knit well when you dampen them slightly and then compact. Millings will knit pretty much on their own dry, but high temps in the summer helps them knit better.

 

You can often get road millings for next to nothing if they are doing repaving in your neighborhood. Note they will probably want you to take at least one full truckload. If you have room for more, be careful what you ask for. If the contractor can dump close to the job site and save on fuel and possibly dumping charges, you may end up with way more than you bargained for if you aren't careful.

 

Crushed concrete is often cheaper than crused stone. Some places specialize in "recycling" concrete. They often get paid on both ends, you have to pay to dump the concrete at their yard, then you have to pay to haul out the stuff they crushed... Crushed conceret was our favorite choice if we needed a cheap solid base material. Note it doesn't drain well, so it's not good for places where you want drainage like french drains.

 

As mentioned a foot tamper or "jumping jack" will beat the snot out of 8-12" and pack them really tight. Down side is they aren't the greatest for getting a nice smooth floor. We'd usually cover that layer with a thin layer to smooth things out, then hit that with the plate tamper.

[jeremy k]

I believe I have this right (correct me if I'm wrong)- Calcium Chloride is what I think the county uses on dirt roads here for dust control - a small amount would be perfect for shop dirt floor.
.

[DSW]

Oh when all else fails, get your kids to do the compacting for you like my neighbor did. :lol:

[Glenn]

Calcium Chloride is a sale much like Sodium Chloride. I would think that much salt that close to metal and you could get a lot of rusting.

[lupiphile]

Pardon, but do you mean calcium carbonate? Like aglime? I've had pretty good success mixing that up with heavy clay-ey soil wetting it and tamping it. At my old shop my forge area actually had a sweepable dirt floor, wherein I mixed up clay heavy fill dirt, and mason's lime( different than aglime) at about a quarter bag to a wheel barrow full of dirt, dampened it well and compacted it with a regular hand tamper, I then raked it to key in the next layer of fireclay, masons lime , and course sand mixed it into a wet plaster and screeded it all over the place. then I trowled it after it had dried a little bit. I'm not exaggerating when I say you could sweep it. I would occasionally spray it down with linseed oil cut half with turpentine, from a pump sprayer. It made for an extremely comfortable work surface. Hope this helps. Take care, Matt 

[HWooldridge]

Just water it regularly with a fine spray head on the hose. I have a clay floor which poofs dust with every step but I can easily keep it under control with water. Years ago, people sprayed old motor oil on dirt but that's not friendly to the environment and I would not recommend it.

No need to compact - just wet the soil. I tend to do it when I leave the shop at night then it's dry the next day.

[HWHII]

I have 1/4 minus crushed granite for 1/2 of my shop. I just rake and water every now and then. It's very sturdy, very little dust and can even roll carts on it.

[oof]

around here they spray used motor oil on the gravel roads, at least they used to. my forge runs on oil. the occasional spill keeps the dust and weeds in check. if you're worried about the environment, veggie oil works just as well.

 

mark

[VaughnT]

"add some cement and mix it up, then compact."  Amen!

 

If you've got the good georgia clay, scrape it up with a rake and then scatter a mix of pea gravel and cement evenly over it.  It's not as good as digging up 4" of the floor, but it's easier than clearing your shop of all the tools, benches, etc and getting a roto-tiller in there.  The mix will sink in to the clay over time.  Might have to do it a few times over the years, but it will still harden the floor and kill the dust.

[RKM556]

Oh my gosh! I go out of service for a couple of days and BAM you guys astound me again with your helpfulness! Okay, so if this is any help to you guys, I live in Georgia. In Georgia, we have super clay-rich soil and my shop floor is basically red from clay. Does that help at all? Thank you guys so much! I would just rent a compactor, but thats more money, which I just put into a sick new coal forge and blower.....

[MLMartin]

I have seen a smith shop that had the floors completely covered with clinker from the coal forge. It seemed pretty compact

[Dodge]

where I used to work, they used a polymer dust control product on the dirt and gravel product storage lots that lasted a good 4 months before they would need to repeat it. Not sure of any brand names but you could google "liquid dust control" and probably get a hit or three :)

[RKM556]

Okay Dodge thank you! I'll look into it!

[VaughnT]

Look at clay under a microscope and you'll see what looks like a deck of cards.  The individual platelets don't have any real surface texture so they can't bond with each other.  This means dust will be kicked up.

 

Add some pea gravel and cement powder to that mix and you get a solid floor.  Cementation of dirt floors has been done for years and is proven.  If you don't have money to rent a tamper, that's fine.  Just use a rake to stir the top inch or so and then apply the gravel/cement mix.  Spray it with some water if you can.  If you can't get a hose there, ambient humidity will get to the cement and get it going, too.  It just takes longer.

[DanBrassaw]

If you've got a welder, you can easily make your own hand tamp with a thick piece of plate. It will take a while to get results, but for a smaller shop or if you can just pick away it at the end of each day, it would be better than nothing. Better yet, convince some neighborhood kids how much fun it is and charge them for the good time!

[Glenn]

Everyone is trying to build a tamper. Why not take that 100+ pound anvil and drop it repeatedly onto the floor, I am sure it will do some serious compacting. (grin)

[DSW]

If you do that you'll either have biceps the size of my thighs by the end, or need a chiropractor! LOL.

 

 

 

A simple 30 or 55 gallon drum filled with water and rolled around works well.

[Frosty]

Okay, got it you have a red clay floor. It's red because it's organicly decomposed mineral soil. I'll just bet one of your problems is softness and gooeyness depending on season. to harden it up you need to start adding gravel when it's wet and soft. The gravel will be driven into the clay and will turn it into "concrete" instead of mud.

 

compacting clay is an exercise in futility except as a temporary measure. Sure it'll get hard enough to bounce the compactor but when the ground water rises in spring it'll get soft again, disturb it during high water and it'll turn to mud. This is the time to add gravel so it gets driven in. After a while, maybe a couple years in extreme situations the gravel won't drive in anymore and you're done.

 

Driving the gravel in is the perfect place for a "sheep's foot tamper." You've probably seen a sheep's foot roller at the dump, big roller with 6"-12" blunt spikes sticking out at 8" +/- intervals. This forces a certain amount of mixing while compacting and is exactly what you want to drive gravel into the clay. HUH? Can't get a sheep's foot roller in the shop? No sweat . . .Well, actually this is where the sweating begins. Instead of the "traditional" tamper forget the plate on the end. Find yourself a piece of 1" or larger dia. steel rod and start walking around slamming it into the ground, pry it loose, pull it out and do it again and again and AGAIN.

 

Don't make me say do this when the floor is wet and soft please. The idea is to drive the gravel into the floor so doing it when it's gooey but NOT liquid is the time. Heck, if it is liquid mud, just walk it in and after it sets up some use the sheep's foot.

 

The gravel will not only turn mud to concrete it'll allow water to flow out and even evaporate to the air. The gravel will become the structure of the floor slab while the clay sticks it together. If you can mix it thoroughly go ahead and add a few % cement, it won't hurt a thing and may work a sweet treat for you. No guarantees, clay can be weird temperamental stuff.

 

NO oil! You do NOT want to become a DEC clean up site, you'll be paying for that circus for years and may not be able to sell the land even then.

 

What calcium chloride does is maintain a percentage of moisture in the soil and hold down dust. It is a salt though much less corrosive than sodium chloride it's still plenty corrosive. Salts are hydrophillic (they LIKE water) and absorb it from the air so soils remain damp. It's not a great idea to just wing it with calcium chloride dust control, clays especially are weird and temperamental, too little and it's a zippo, too much and the ground gets sticky tacky and everything rusts. We did a lot of calcium chloride tests in the lab to determine how much to use on THAT piece of road. Each sample typically represented about 1/4 mile if the contractor or project engineer were feeling bold.

 

So, without being able to walk the ground I'd start driving gravel into it till I couldn't drive any more and live with the results. That's just me though. Swapping posts over the internet is NOT the way to design a soil project. But what the hey. <grin>

 

Frosty The Lucky.

[meancoyote]

When the roads were dirt around here(most are now paved) , a guy down the road used to pour used motor oil on the road to keep the dust down. He got in a bit of trouble for doing that, and in the end, wished he never did it. The odd thing is, right before they put the asphalt down, they sprayed the dirt with oil. maybe it was special oil, I dunno. My shop floor is dirt. I want to put paver's in someday.