New home for tractor - advice pls

[RichT]

Planning a DIY 36'x24' pad for a steel barn (SOCAL area). Std 4in pad with 2-4in gravel underlayment, 12"x12" footing. If my calcs are right, about 15.5 yds of concrete. I've done a moderate amount of concrete work, but never anything this size. Monolithic pour, good access to pad area, shouldn't need pumper. Probably 2 truck loads.

For 4in slabs, most seem to recommend 1" deep joints on 10' spacing. My plan is to create 6 12' squares with joints at 12' and 24' on the long side and 12' on the short side. Methods I've seen for joints: hand tool, saw cut, and hard board inserts. Suggestions?

Finishing. This is the part I'm most worried about as I've never finished anything this size. My plan: bull float, edge it, tool or hard board the joints, wait for bleed water to evaporate, wood float (using plywood platform to get to interior area), broom finish. Suggestions?

Do you think this is too big for a DIY project? I can excavate with my Kubota BX22 and have plenty of wood for forms. If you think its feasible for a DIY project, how many of my friends should I deputize to help?

 

[aloha]

A good online source for concrete info is:

Concrete Network

Don't forget to take photos.

 

[RichT]

aloha, thx for link. I've been to a few of these concrete forums. Good info, but they seem to (generally) be very conservative about DIY projects. Many are contractors and I respect their opinion, however, I think that many of the tractor folks here are more inclined toward DIY projs. Which is why I posted here.

 

[Dartagnan]

First, let me say that I'm no expert....

But I have done a few pours.
That is a very big pour for 1 shot, I would try to split it in half or even thirds. (Seam stability handled by drilling end of first slab and inserting rebar dipped in wet mortar mix every 2ft or so)
Make sure you have plenty of help for the screed work or rent a power screeder. Also should pick a date with low humidity mild temp...hard to work crete when you are down with heat stroke....

You might even go so far as to get some practice, pour a generator pad or garbage can parking area or sidewalk, or mandoor stoop,(Exterior crete should have a broom finish for saftey but you can still play with it for a lil while to test your ability) just to see how fast you can get the texture You want before setup.

For an indoor slab I would prefer a smooth finish, broomed crete is hard on your knees, elbows, and back when you are working on equipment. Not that difficult with a decent trowel and bucket of water. Bull float as good as you can. Make sure you have enough handle before the truck gets there! Start early on edging and troweling the peremiter. Don't forget to hammer tap the forms to knock the rock back into the crete and fill voids. Make sure you have your knee boards ready before pour date, they should have one smooth side and some kind of handle to pick them up with( I staple some old load strap webbing to mine and round over the edges and knock the corners off)
Buy a box of latex gloves, lime is hard on the skin. Have plenty of your favorite sport drink on hand.

And the key thing to remember... don't judge the job until its turned white....what looks mediocre wet can look great dry, and once you get the building on top, you won't be able to see but 20-30% of the floor at one time anyway.

/forums/images/graemlins/smile.gif
Dart

Just as a note, it took two "pros" about 6 hours to hand trowel my dads 20x30 slab. You might also look at renting a power trowel. Also, get a few bids on the job, and compare cost dif between them and DIY, you might find that the extra cost is not that much when you factor in the possability of "losing" your pour.

 

[Dartagnan]

RichT

Sorry about the lenght of prior post /forums/images/graemlins/wink.gif and yes I saw that you have some prior experience, but I thought I should be explicit for the benefit of others who read this thread.

Good luck!

Dart

 

[Dartagnan]

The thing I always forget,

J bolts, sill anchors, what ever you want to call them, don't forget to have them on hand and know where they go that they won't interfere with wall studs.

Dart.

 

[EddieWalker]

Have you considered using sand instead of gravel for your base? Gravel is harder to achieve compaction and usually more expensive. I prefer sand due to its ability to reach almost 100% compaction with out any major equipmnet. Sand just compacts on it's own! It's also easier to work with and in my area, it's cheaper than gravel or base rock.

Since you're going to be working on your tractor in your barn, I would highly recomend a smooth finish. For me, rolling floor jacks, cherry pickers, engine stands and just about anything else on wheels will be easier and nicer with a smooth finish. If you spill any oil on a brushed finish, you will NEVER get it cleaned up.

My last pour was three times the size of yours, but I had a crew do it. There was between 10 to 7 guys working on the main pour, and the finish troweling took the rest of the day. They do this everyday and know what they are doing.

I paid $3 a foot for my last pour wich included rebar, concrete and sand for a base. That was a little on the high side, but the price of rebar took a huge jump and that comes out of my pocket. I'm in East Texas and I'd expect labor is quite a bit cheaper than you'll find in SoCal.

If you have plenty of help, rent the power fan thingy that smooths the surface and have the patients to get it right, then go for it. I've never operated the fan thingy, but have watched it enough to realize it's not overly complicated, but also takes some effort and knowledge of when it's dry enough to work on but not too dry either.

Expansion joints and conctrol cuts are mostly used outdoors due to the fluctuation temps and conditions. Your pad is small enough that I wouldnt' bother with them. If you're really concerned, have them add another sack to the mix or add fiberglass to it.

Before I got too far into the planning, I'd call a few local contractors and see what they'd charge for doing it for you. Also ask what the difference would be for them to just pour and finish. You set the forms and rebar.

The dryer the mix is when you pour, the stronger it will be. It shouldn't bleed water after smoothed. That sounds like you mixed some concrete yourself and had it too wet. The driver does this everyday, and is a good source of info if you ask. They will also water down a load just as much as you want and laugh about it with the other drivers when he gets back.

Enjoy,
Eddie

 

[Syncro]

<font color="blue">......Many are contractors...... </font>
<font color="black"> </font>
We're in the business and you're scaring me. For something that big hire at least 1 guy that knows how to do it, when its all done you want to feel good. However to answer your question, it goes something like this:

Assuming you have the necessary permits and engineering done, I'd pour the footings first then the top slab in 2 or 3 pours. Cold cut the joints (2" or so deep and the closer the better eg 8'x8') in 24 hrs with a rented wet diamond saw is the way to go. A skill saw with dry abrasive blade would also work. Concrete is only as good as the sub base, so put extra $$ into a well compacted, level, root free road base or gravel. Don't forget curing compound, use a garden sprayer and get cure on asap.

If you're handy its do-able, but there is a lot to know and I'd sure consider at least getting some experienced help. Placing steel, complying with codes, where to start, hand signals with the mixer truck driver, etc etc could quickly become too much alone.

 

[Nat]

I'm not a concrete man but to me MONOLITHIC means ONE. I've got a 30 X 36 shop that utilized a monolithic footing/slab and if you put cut or exp joint, it would have to crack the footings for the control joint to move. A monolithic floor that is covered and in the shade shouldn't crack. It is the uneven heating and cooling of a concrete slab that causes most cracks. If the ground under the slab is 60 degrees and the surface is heated quickly to 80 degrees tha top will expand at a faster rate than the cooler bottom and will cause an expansion crack, and that is caused most often by the sun heating a relitivly cold slab. If it is inside the room temp won't raise much faster than the temp of the ground below it and shouldn't crack. I am from the south, so don't know how it is done in the colder climates, but here we don't cut control joints in a molithic pour. Hope this is some help, Later Nat

 

[rambler]

Something this size is DIY only if you have a crew of friends who have worked concrete somewhat before, and at least one is very familiar with the tools & procedures. Once the load is sitting there, you need to have everything you need there _now_ & be on top of the labor, or you will pay dearly for the learning curve.

Sometimes contractors get a price break on gravel/ crete, and they end up doing the work for you & not cost much more. Some contractors will use your friends for the crew, so you only hire the one guy...

--->Paul