How big of a slab could I do by myself?

[sandman2234]

ok I'll bite
what's BFI?

OK, one more question while I have you all.

The walls of the garage are concrete block. Should I pour against them or put in an expansion strip? If so, what? My inclination is to put in a piece of treated 2x4, held by Tapcons, so I have something to screed against. Would something thinner work as well, like 1/2" treated plywood?

If not, how do I screed against the wall?

I think somebody mentioned this, in the reasons they poured strips along each side and then poured the middle. Gives you something to hold the skeed without bumping the wall. You can do a couple strips and just finish them with a trowel.
David from jax

 

[paulsharvey]

OK, one more question while I have you all.

The walls of the garage are concrete block. Should I pour against them or put in an expansion strip? If so, what? My inclination is to put in a piece of treated 2x4, held by Tapcons, so I have something to screed against. Would something thinner work as well, like 1/2" treated plywood?

If not, how do I screed against the wall?

I have done what you are saying and just used cut nails to place the fiber expansion joint and screed off that. A 2x4 would work as well, but then you have a 2x4 stuck in your concrete, that looks like crap. You could strip that 2x4 after everything is screeded and work it back by hand. I "think" the 2x4 should offer a flexible enough piece that thermal expansion shouldn't be a problem, but I don't know that for sure. What you describe is exactly what expansion joint material is made for.

 

[EddieWalker]

Concrete expands when it's hot, contracts with it's cold. The most common way to deal with this is putting a 1x4 board between each slab.

For your slab, and especially since it's going to be done in three pours, I wouldn't worry about it.

For the existing wall, just use a chalk line, or draw a straight edge along the block. Then while you just follow the line as you screed your concrete. If it starts to get wavy, or not very flat, turn your screed board along the wall and work it that way to create a flat, level surface, then screed off of that surface.

Do you have an SDS Rotary Hammer Drill? They have come down on price quite a bit, but they are also cheap to rent. You will want one for drilling into your block wall to slide the rebar into it. I normally use Liquid Nails, or something like that, to anchor the rebar in the holes. Just fill up the hole and then slide the rebar into it.

OK, one more question while I have you all.

The walls of the garage are concrete block. Should I pour against them or put in an expansion strip? If so, what? My inclination is to put in a piece of treated 2x4, held by Tapcons, so I have something to screed against. Would something thinner work as well, like 1/2" treated plywood?

If not, how do I screed against the wall?

 

[paulsharvey]

If you do the "outside" two pours first, the new slab only has a single rigid point *the CMU walls) and can expand/contract on the free, inside edge. I would place expansion joint between the two outside pours and the inside pour. I dont double Eddie on leaving a 1x4 in place working, but it looks half butt, isn't cheaper than expansion joint, which is made foe the task, and is easy worked with, and readily available. Once all 3 pours are complete, wait 28 days, and caulk over the expansion joint with a polybutylene rubber, and you will have a good looking point.

BTW, I did skip expansion joint in mine, but it's not the "right" way to do things

 

[paulsharvey]

Also, someone mentioned pouring an entrance at the door. I would definitely want expansion between this e trance "ramp" and the main slab. It also would be a good idea, even if it's just a 3×12, or 3x13-14, extending 6-12" left and right beyond the door way.

 

[Egon]

Rethink concrete pavers. Installed on a proper base they are much easier to handle than concrete.
On the base sprinkle some lime/cement over the base just prior to laying the bricks. For finishing sprinkle concrete and very fine sand on the floor, brush it smooth and wet it well and keep wet for a half a day or so. Using a rough cut 2x10 plank under the jack eliminates the problems previously mentioned.

 

[EddieWalker]

I like concrete pavers for a lot of things. Walkways, patios, even driveways. But not for a parking area, or the floor of a building. For me, sweeping is very important, and nothing beats the flat smooth finish of concrete. Even if it's not perfect, like my concrete work, it's still easy to sweep.

The other issue with pavers is the cost. Off the top of my head, I think the last time I did the math, pavers where three times as much money as concrete.

 

[EddieWalker]

Nothing wring with expansion joints, but for such a small building, I think it's extra work without any measurable benefit. Especially if you pour it in three pads.

I agree that having the seams of the three joints showing at the front of the building isn't ideal. But for me, I wouldn't care about that. If I was hiring it out, and I was expecting it to have a really nice finish, a lot better then I'm capable of, then yes, make the entry perfect to. But for a DIY project, for a utility building, when cost is a factor, I don't see the advantage of making the project any harder.

 

[quicksandfarmer]

Do you have an SDS Rotary Hammer Drill? They have come down on price quite a bit, but they are also cheap to rent. You will want one for drilling into your block wall to slide the rebar into it. I normally use Liquid Nails, or something like that, to anchor the rebar in the holes. Just fill up the hole and then slide the rebar into it.

I have a cheap one and it's one of my favorite tools. It makes Tapcons a cinch.

One technique I've read about is to use a 2x6 ripped in half as a guide along the walls. Align the bottom of it with the level of the concrete and attach it with Tapcons. Use a 2x6 as your screed board, and cut a notch in the screed board so that the bottom is flush with the bottom of the guide board. Once the concrete is placed remove the guide board and finish the surface.

 

[EddieWalker]

I can see how that would work. But I think it’s an extra step that isn’t needed. With a straight line against the block, it’s pretty easy to get the concrete where you want it.

Just start working the concrete as soon as you have enough in there to spread it out. Then work your way back to the mixer.

When pulling the concrete after dumping it, don’t worry about what goes under the rebar. Just keep pulling what’s above the rebar

Get a tool for pulling concrete. It looks like a super wide hoe. I think mine is about 18 inches wide. I broke the wood handle on it a decade ago and now it has 3/4 copper pipe for a handle because that’s what I had laying around.