How to Harden Dirt: Lime or not to lime.

My house is surrounded by forest and sits about 30' past the end of the crest on a spit of cleared land (incredible view) where it tapers down on three sides of the crest. Part of the runoff heads towards the house. About halfway to the house is a 6" deep angled trench that redirects the water off towards the right side of the house where it runs down into the tree line.

On the left side of the house is a 20x20 concrete pad carport. About 6' deep section of the ground in front of and the width of carport turns to mush when it rains. I can't afford, nor to I want to extend the concrete out into that area. Pending a resolution, I dug a small trench so the water that pools there runs off to the side rather than pools. When rains I will sometimes not use the carport to avoid rutting the mud in front of it.

The dairy farmer next door suggested blending lime into the dirt in that area to harden it up. When I read the big red warning labels on bags of soft powdery lime about burns :shock: or blindness from lime dust it gives me pause so I'm soliciting feedback from the group.

Has anyone done this type of thing? Is there an alternative (aside from gravel) that I can do myself to firm up that section of dirt? I'm open to any viable suggestions!

Thanks!

-Bill
Dallas, TX
1948 Ford 8N (built in '47)
Front mounted Dist, Converted to 12v
http://photobucket.com/Ford_8N

its done everyday in construction sites for soil stabilization.

Firming up the dirt is definitely possible. I once bought a farm which had a storage area, and in this storage area, there was a place where they stored lime. I can tell you that this area (outside) was VERY HARD, and I had to chop it up with the CAT D6 ripper so I could grade the roughened, packed terrain.

What you need is Portland Cement, not lime. Portland cement is basicaly cooked lime and the product used to make concrete get hard. You can also use Quick-Lime but it is not usualy available in small quntities for the home owner. To your question lime and cement are very little more dangerous to your health than the dirt you will be mixing it with. Masons have virualy taken bathes in it for centuries. Yes if you stick your head in a bag full and leave it there you will likey die and/or go blind. Everything in life will kill you if you over indulge including mom's home cooking. Just use reasonable caution like anyone with his wits about him would do, mix it in your dirt and you will then have what is called soil cement, you may need a bit of stone on top just so feet dont track when wet.

It's obvious the existing fill has fines or organic matter in it, maximum moisture or saturated and it fails. A slab like that requires an apron of good material in front of it, ideally, it should be excavated, subgrade set so it drains out, install drainage, then place and compact a well graded gravel or crusher run (gradation analysis of the sieve size aggregates with a variety of all sizes so it compacts 95%+)

You could excavate, and replace with gravel, use a tiller, mix in portland cement, a fair amount, compact and soak creating a kind of a soil cement. Hard to say what the existing material will do, bad material is bad material, mixing portland cement into it may work or it may not work, just create a crust that is brittle and fail when things change under it, freeze/thaw etc. etc.

You could excavate and use a stabilization fabric, but again you need good material on top of it, this helps when what is underneath is really unsuitable, but just too much to remove or correct, excavate, place fabric, drainage and fill with stable material, and compact.

I disagree with the comments about safety, I do know this, wet concrete/mortar will burn you, it effects people differently. I have seen photos of some nasty burns, years back in A.C.I. books, warning of this, use rubber gloves and or other protective gear, and get the MSDS sheets on anything you use! I'm not sure whether portland is caustic, or its the lime, when it's wet, it's alkaline, I'm sure someone can add to this about the lime or portland. I can tell you that when I have handled mortar, without gloves on, just a few simple exposures and my fingerprints are gone !

Read the below, it provides some insight on how it burns you, wet concrete and mortar materials are quite nasty, let it go long enough it will cause serious damage to your skin !
Concrete Burn article

Portland is caustic, lime is caustic. Hydrated lime is caustic and a lot more reactive. They also pull moisture out of anything they contact, similar to but not as serious as anhydrous ammonia. You need to have a source of water handy to wash eyes out in case of a splash.

Years back I drove a concrete truck and a laborer bent over to pick up a wheelbarrow just as a clump dropped from the chute into his wheelbarrow. He got a chunk in the eye. I grabbed the hose and got him in a headlock and sprayed his face until he got loose. After he got done cursing he thanked me.

Yup--a relative worked 40+ years at a big concrete plant, and one day they were emptying the barrel of a broken truck before the concrete hardened. He got some in his pants pockets and down his shirt, where it was stopped by his tucked-in belt. By the time he noticed it, it had burned him so badly as to require skin grafts and months off work. Burn doc said that chemical burns are some of the worst because they keep burning deeper and deeper as long as the chemical is still present. Goes to show that while usually lime and cement are reasonably safe to work with, they can be quite dangerous in the right circumstances.

Yep, I thought both were caustic, but no sense in guessing about it, that article gives some insight on how it burns, and a lot of people don't even consider it dangerous, I've seen this in the commercial building construction industry with concrete and masonry, be advised and be safe !

Exactly what I am talking about, the discoloration and effects are gruesome once it sets in.

Not for the lighthearted, this is exactly what it will do to you !
Concrete Burn image

Billy NY is correct.....

in clay type soils one can use crushed limestone (which is abundant in Texas).
This is to be worked into the soil. In fact they have augers mounted on large machines that look like the tines on a rototiller. The Crushed limestone should have a high % of dust (fines) in the (dry) mix. Water is added at the time of tilling. Mechanical compaction would be accomplished after that.

Portland Cement would be used in soils that don't contain much clay, (sandy or decomposed granite).

The organics need to be removed.

As stated, 'bad soil is bad soil'.

YOu mentioned forest....... I hear 'organics'. How deep is the forest die off? You mentioned, a spit of clear land w/a view'. It's quite possible a lot of the organics have already washed away. Most 'hills' have a fair amount of solid just below the surface.

BTW, Billy NY has embedded links in some of his previous posts about soil stabilization and management.

......sl

It's been about 5 months since the last post so I thought I'd give an update.

I decided to get aggressive and rented a ditch witch and dug a 175' french drain across the front of the house (14' out), carport (5' out from the pad) and storage shed (2' from the door) to redirect the water completely around the structures. The center of the house is the high point so water runs off in both directions. I then laid a 36" wide raised gravel side walk over the top of the drain for the sections across the house, and 5' wide out from the carport pad so that any water coming down the slope goes under the gravel path and into the drain. The only thing left to do is to finish tapering the ground from the house to the raised path so that water on the house side of the drain runs down towards the drain.

Seems to have done the trick!

-Bill
Dallas, TX
1948 Ford 8N (built in '47)
Front mounted Dist, Converted to 12v
http://photobucket.com/Ford_8N

See if someone in your area can get you some Bentonite and mix that into the surface of your pad, that stuff will set up nearly as hard as concrete. its a naturally occuring mineral out west . you can get it in bags and scatter it about 1/2 to 1 inch deep and till it into the surface 2 to 6 inches deep, pack it down with some moisture and it should firm things up for you.