Concrete Questions

[Bird]

I would say the rebar is absolutely necessary, although the concrete wire can be used instead, but I sure wouldn't. I'd want a minimum of 3/8" rebar on 16" centers (can go up to 24" instead of 16") and of course you need the 2" stools to hold the rebar up in the center of the concrete and you need the wire to tie the rebar.

Nothing to it except a lot of expense and a lot of hard workas others have mentioned.

 

[N80]

Sounds like I need to put this on the back burner until I have the budget to let someone else do it. Thanks guys.

 

[EddieWalker]

4 inches is plenty thick for a compact tractor. If you get into an RV or somethng really heavy,then you need 6 inches. These are not accurate numbers since a pour is based on the size of lumber used for the forms. A 4 inch pour is actualy 3 1/2 inches thick.

Rebar is a must. Putting it on 2ft centers is fine for a parking pad. I'd use number 3 rebar, which is also called 3/8's rebar. Number 4 is 4/8 and so on.

Wire is cheaper and easier for a crew to lay, but 99% of the time, it ends up at the bottom of the pour and doesn't do anything. I avoid it like the plague. Those who have it like to think it was done right, but it's not. It will always have areas where somebody steped on it and ends up at the bottom of the pad. Usually you don't know it until you tear it apart. In every pad that I've dealt with that had wire, it was on the bottom.

To increase the strenght of your pad, you can dig a footing at the edge where your tractor will drive up on it. Make this about a foot thick, but a shovel width wide. This extra conctre will go a long ways to stop any cracking that might occur.

I just had a job for a cement pad bid on that came to $2.75 a sq ft to have the land graded, forms set, wire mesh and 4 inchs of concrete poured with a broom finish. I didn't want the wire mesh, and while discussing that change, the client changed his mind and we're going to do something different now.

Concrete is around $100 a yard and most trucks can hold 10 yards. Some a bit more, some less. You pay for what you order, so if you need 8.5 yards, that's what you order and pay for. If you are short, you will have to pay a premium for them to come back again with more!!! If I thought I needed 8.5 yards, I'd order 9 and have a plan to where I wanted the extra dumped.

Remember, the cement truck will also want a place to clean out his truck and wash it down. I have them do it on the gravel driveway of my place, or let the client decide where at their place.

For the size of your pour, I'd hire it out. Learning is something that you don't want to do on your first pour. It will take at least three guys to do it right, and if you don't have two friends who know what they are doing, it will be a mess. Remember this, if you mess up on concrete, it's a mess that you will have forever!!!!

You can save money buy grading the land, adding the base material if you need it, setting your forms and tying the rebar together. I paid a crew $500 in labor to pour 30 yards of concrete for my house after doing all the prep work. Concrete at that time was $80 a yard.

Hire it out and have it done right. Watch what they do and you will realize that it's not something you want to tackle. Physical conditioning is only part of it, skill and experience is the important aspect of getting a smooth, flat surface before it dries on you.

Good luck,
Eddie

 

[seymojo536]

I also say hire it out. Concrete is the one project that if you do try to do it on your own and screw it up, you're stuck with it for a LONG time.
Find someone who does flat work for a living and buy him a couple of nice cold ones. He'll be glad to fill you in on just how much work you are looking at.

However, if you are dead set on trying to do this yourself, I would suggest you do it in several pours. Say do 10x16 or a quarter of the floor at a time. Start at the back and make your mistakes there. Find out what the mininum amount is the concrete company will send (some around here require 3 yards or they won't come) and how much extra this will cost you in delivery charges.

DO NOT pour on top of the topsoil. That needs to be scraped off along with 8-12 inches of the clay and a good base of 467 gravel laid down and compacted. Do plan on laying rebar and/or wire down and a vapor barrier under that. Put a couple of drains in now. It makes cleaning a whole lot easier.
And if you can find the money, lay down the pex pipe that you can hook up to a hot water heater and make the place cozy when the cold weather comes. Once that concrete dries it's a real bear to cut lines to put in a drain or water.

 

[RobJ]

Not really that hard and you only need a few crude tools, rubber boots, and a dry day.

Build up a form as deep as you want. The center of the foundation of my garage is 4", it holds all my crap. The beams around the outside are about a foot, the walls of course load them up. The house and garage sit on that nice hard clay. You do need some plastic as a vapor barrier, it's cheap. Rebar is overkill, some 6x6 mesh is all you need. I think it comes in a 5x50' roll, if you have extra on the roll you can double it up. That clay you have makes a nice bed, scrape off the topsoil, refill with more clay, then water it real good, let dry and it's compacked enough.

Personally I like it when people put the posts in..no roof yet, and pour around the treated posts, makes it solid.

Usually a truck is 10 yards, but you can order 9, 8, 7, or 5. You pay for what you order. When the truck arrives the concrete will be pretty thick, have the guy test pour a little to see, then you will probably want him to add some water, 10-15 gallons for a 10 yard truck may do the trick. Now people will reply that this will weakens the concrete, yeah maybe a little, you are not building a 70 story office building. Also when you order the concrete you can order the strength you want, it's measured in psi. I think my garage is 4000psi and the house was 6000psi. Cost more because I think they just add more portland cement. The concrete guy should know what you need for a small pad. Now when you add some water this will make the concrete easier to work with and give you a little longer work time. This isn't that big of a pour, my 20x24 garage had the truck pulling away in about 20 minutes. Remember your ground that you are pouring on does NOT have to be flat and level, just your forms. If you are 5" in one spot, don't worry about it.

You can use a regular rake or whatever to move around the concrete. Can't recall what the big hoe looking things are called, get them at HD or lowes. Try and keep your wire in the middle of the concrete if possible.

Once the concrete is poured and spread, you can use a 2x something to flatten it out, just sort of hold it on the forms and screed it out flat. Some will put a stake in the middle to help with the leveling, the stake is level with the sides. You might be able to rent some tools, what we call a jitterbug is nothing more than some mesh on a handle, you bounce it on the concrete to push the aggregate (rocks) down.

About this time the excess water will start pushing out of the top and sides, let it do it's thing(total time since the truck started pouring...20 minutes).

After that you can start to smooth it out a bit more. A powered towel is what is used to make it smooth. It takes 2-3 passes at just the right time to do this. For a shed it's not needed. Actually some like to put a broom finish on anyway. In reality you could drag a piece of plywood across it once and it'll be good enough for your purpose(you are not tiling over it right).

Pop the forms off the next day and start building on it(IE pour on Sat morning, build on it Sunday morning...after Church :d) and drive on it a couple days later. DON'T cut the forms all nice and pretty to the exact form size. Why? because you are just wasting wood that can be used elsewhere in the building. Notice my pics.

I'd have at least 1 helper, any more and you'll need more tools. Once your form is built, all you are really doing is spreading, leveling, and some smoothing. Initial it then walk away!! The die-hards will say to cover it with burlap, keep it damp for a day or so. Again you are building a pad here, not a super highway!!

Couple links to my concrete work.

Good Luck,
Rob

PS, want to save some real money? Forget everything I just said!! The clay you have makes a real nice floor. If it has the little rocks that we call iron ore...even better. It's hard, will support a ton of weight(will not sink if you jack your tractor on it), and with a roof it will stay dry and hard. Just scrape off the top soil and replace with the clay.

Elkhart House Project
Elkhart House Project
Elkhart House Project
Elkhart House Project
Elkhart House Project
Elkhart House Project

 

[jonbravado]

I am about to start my project like this in a couple of months - i am using telephone poles for the posts, metal roof, and will be using gravel or 'slag' for the floor - i was pricing kits and concrete and decide to make my tractor shed on the cheap, but it will be plenty big and plenty dry when i'm done.

good luck and keep us posted.

J

 

[LD1]

I have poured a lot of concrete in my day and I also think the rebar is overkill.
It is also more expencive and a big hassle. I would use the wire and also have them add fiber to the cement which will also make it stronger. 4" will be pleanty thick. I am going to pour my garage in a few months and it will be 4" thick. I also agree that you need a good base. Around here we use #57 lime stone. (3/4"-1" stuff). 4 inches of that and it will lock together and some of the concrete will seep down into it and it will be a lot stronger than 4 inches poured on dirt.

A couple of tools that I havent heard mentioned yet
1. A good transit-we usually borrow one from work
2. A power screed-I think only like $35 to rent, well wort it
3. A bull float- again not vert expencive and you dont have to walk on the concrete to finish it due to the long handle, but this depends on how yo want it finished.

Another thing I would suggest is to use the transet and pleanty of grade steaks. A floor that big, if you only use your form boards as a reference, it is real easy to get low spots in the floor. It may look good but you will know it when it rains. Another thing you may want to do if you can get a transit is to slope your floor all one direction. just a couple inches every 10-15 foot is pleanty and it will really help when it rains or if you want to hose the pad off.

Finally, about the wire always ending up on the bottom. What we do is once the concrete is powred and leveled, and your just waiting on it to set up enough to finish, we will start at one side with a hook and start pulling the wire up into the concrete. Don't worry about the boot prints because when you get done pulling the wire up, use the bull float and start leveling again.

Good luck to ya

 

[EastTexFrank]

Mixing, pouring and finishing cement is what my father did all his life. I worked for him one summer and that was the reason I decided I really needed to go to college. I'd never worked that hard in my life, before or since. I think that's what the old man wanted to achieve anyway, and it worked. He ran on me pretty hard for 3 months but he earned my respect by what he did to feed, clothe and keep us all.

Unless you are going to use fibre cement I think that you need something to reinforce it. In this case wire would probably work just fine. Make sure you have a good base to start with and I would have thought that 4" would have been plenty thick for a compact tractor.

You can do it yourself, especially if your B-I-L is willing to help and has the experience, but be prepared to sweat. Like so many things the prep work is vital to success. Make sure the base is sound, the forms are square and level and everything is ready for the pour because once that starts, you are working against the clock.

 

[Western]

Laying the rebar will be the easiest part.
It will probably cost you in the $200 range for supply's , Another consideration, also higher cost, is reinforced concrete, either wool, fiber or steel shaving. Ask your concrete supplyer about those options. I've be told that rebar isn't required with steel blended concrete. (sceptical)

Personaly I like rebar with fiber cement but the surface may have small "hairs" in it.

 

[Dargo]

I've had over 700 yards of concrete poured at my place in the last couple of years and will have another 96 yards poured this Friday. I don't have any concrete where a vehicle will drive on it that is less than 6". All of my parking areas and driveway is 6" 5000 psi concrete with 4 gauge wire (the wire is about 1/4" thick and comes in sheets - you can't roll that stuff). I use rebar between joints and on edges. There I used grade 60 #5 rebar. In my barns the thickness varies between 8" to 10" depending on what is going to be placed in each barn. Around my pool and my porch I used 2X6 forms, so that concrete is about 5" thick or so. That concrete will only have foot traffic.

My theory on concrete is that I only want to do it once. Long ago I tried to go with concrete as thin as I could and only used the standard 3500 psi concrete. With some heavy equipment, I got to rip all that stuff out and do it again. It's far less expensive and easier to do it right the first time. Inside my newest barn we just parked a pumper truck inside with a boom arm. That way each concrete truck just drove up to the back of the pumper truck and unloaded into it and the boom arm reached where we needed the concrete poured. I can't recall, but I think the concrete trucks need at least a 16' door to be able to drive through; or maybe that was what was needed for the pumper truck. Either way, it sure made it easier to get the concrete where it was needed!