I'm working on prepping for my new 36 x 48 shop and I am about to the point of the final leveling and ground prep. My first question is about small roots. The shop sight is in the woods and all of the trees and stumps are gone, but there are small leftover roots sticking out everywhere and there is no good way to get them up. I was wondering if this is going to be an issue, or if they all got to go. Do I need to cover the area with fill dirt and/or crush gravel?
My next question is about the final leveling. I bought a string level and was planning on using the string and placing stakes to mark how far out it is, then add or subtract dirt and drag it with a box blade till its pretty close. Does this seem like I'm going about it right? Do you guys have any tips to give me? Thanks in advance!
As long as you scraped off the top few inches of organic material, you will be fine. If the area is lower than you need, just bring in sandy fill dirt. Spread it out and compact it with a plate compactor every 6 or 8". Just make sure your footings are 12" or so into undisturbed soil (unless you are doing a pole building).
If you can get ahold of a transit or laser level, you will have a much more accurate and easier time getting the grade right. Set up batter boards outside of your building footprint at your desired final top of slab. Then you can run string lines across to measure grade and set form boards.
http://extremehowto.com/pour-a-concrete-floor/
I didn't read the article, but the diagrams look helpful.
Just make sure your footings are 12" or so into undisturbed soil
not so, need to be compacted soil, just because its undisturbed doesn't mean settlement won't happen due to uncompacted subsoil. excavated into undisturbed soil then run a jumping jack down the footer couple times
Location makes a huge difference as to how things are done, so one may want to check with your county office and see what the codes are. Even though some say they are out in the "country" and there are no codes, there will still be minimum guidelines to follow. If there wasn't, then you'd have anything tossed up anywhere.
For instance, most of the places around here will either have footers poured at frostline, then have either a poured wall, or concrete block wall built up to a block or two above ground. All grass / sod has to be eliminated down to "undisturbed soil" then 9 times out of 10, the area will be backfilled with #57 crushed stone. Some compact the stone and some won't. Across from my dads house, they built three houses....two on slabs, and one on a crawlspace. One house had a foundation put in, then it was backfilled with stone, then concrete. The one beside it, same contractor, built the house with a foundation like the first (block down to frostline) then it was backfilled with sand, then compacted some. The reasoning was that crushed stone settles, although they say it won't, but sand will compact down and once it is, cannot settle any more than that. That is what was tried. The last house was built with a foundation down to frostline, then the block laid, then the center dug out. This left a crawlspace which had to have floor joist put in. Each home had it's own problems, but only one complained about the floor. That was the house with the crushed stone although the problem was the laminate flooring, so I don't know if it was related or not.
As far as the OP, if you have, or had, a lot of trees, you want to get the stumps out, the large roots out, but depending on the tree, you may not be able to get all of the hair roots. Some trees can send the roots a long ways.
If it were mine, and I imagine that our summers may be close to what you have year around, I would get as much as I could out, but don't fret over every little root. If you are going with a pole building, I'd get it erected and when it comes to the floor, I would either go with crushed stone, or go with a "washed sand". In going with a washed sand or a clean sand that only has very small stones in it. If you use crushed stone, then I would layer it, tamping each and every layer, and go at least a foot deep with the stone.
If I went with sand, I would make sure to also put the sand in , in layers, dampening each layer, then going over it with a plate tamper. The sand would go faster than crushed stone as far as tamping. Once it's all down, either material, then lay some heavy thickness of vapor barrier down, then go with your radiant heat, insulation, or whatever you want to do.
Where you are at, I seriously doubt that going down to frostline even exist, or if it even gets cold enough to worry about it. I would make sure, and again check with your county on codes, but you WILL want your outside edges thicker. If you plan on a hoist in the future, then make sure you have thicker concrete where it would bolt down to. You also may want to have a pour done where you have thick beams running each direction when poured.
On thing to remember, the floor and foundation is the main part of the structure. If it's a half *** job, then everything on top of the slab may as well be also. I wouldn't worry about wire mash either, but I would make sure that the floor has rebar through it. This keeps the floor from dropping if it happens to crack. The rebar will keep both sides of the crack, even, and not allow a tripping hazard to happen.
Good luck and looking forward to the build pics of the new place.
