DIY Slab. Yes or No?

[frankd]

My father and I are looking into pouring a 20x30 slab for a garage in Upstate NY. I want to pay someone to do it but he seems to think it'll be a piece of cake. In case he wins this battle (the old man probably will), I was hoping for some pointers.
We were thinking of going with 6 inches of fiber reinforced concrete over 6 inches of gravel. The location is kind of in a valley so we do get quite a bit of water. I was thinking of getting some extra gravel and building a gravel mote/french drain around the perimeter to keep the water away.
Also, not sure what to do in terms of rebar size and spacing.

Does anyone have any pointers/tips? A neighbor just had a similarly sized slab poured and he paid a contractor $2,000 (not including material) to tamp down the gravel and pour/level the concrete. He build the forms himself and spread out the gravel. Just basically paid $2k for the tamping and pour.

I thought that $2k sounded reasonable but my father thinks its way too expensive.

Any thoughts/tips/advice would be appreciated.

 

[The Cobbler]

I would not attempt a pad myself. I don't know enough about concrete to be sure I would do a good job.
I have seen way too many DIY concrete jobs that failed , looked like ****.
2k is a reasonable price , get him to tie ( you supply) rebar on a 16" grid for that price and forget the fiber

 

[frankd]

I would not attempt a pad myself. I don't know enough about concrete to be sure I would do a good job.
I have seen way too many DIY concrete jobs that failed , looked like ****.
2k is a reasonable price , get him to tie ( you supply) rebar on a 16" grid for that price and forget the fiber

I'm definitely leaning towards paying someone to do it but the old man is pretty stubborn. He is a painter by trade but very good at woodwork and basically built the cabin himself (except for plumbing and electric). But he has no experience with concrete and I'm worried that we're going to realize we're in over our heads while the cement truck is halfway through pouring the concrete.

Also, why do you say to forget the fiber? It seemed like a relatively low cost add on/cheap insurance

 

[Jeff Ivers]

If you are doing a single pour, that size pad is large enough that screeding the concrete will be very hard work. I would use rebar on 2' centers running in both directions with joints tied together and held up off the ground with rebar stakes or purpose built stands. Use minimum 5000 psi concrete.

 

[ConCretin]

Give my Guide to Floor Slabs a read for some thoughts on the process. Maybe you could do all the prep yourself and hire someone to do the place and finish. If you haven't poured a slab before, I guarantee it won't be flat or smooth when you are done. If that's ok with you, carry on.

 

[NUTTSGT]

How old are you and your pops ? Concrete work isn't for the faint of heart nor is it going to be a piece of cake unless you're writing a check.

 

[Michigan Mike]

You got more help or is it just you and your dad. If it is just the two of you and you can't get more help hopefully with some experiance I would say no.

 

[930dreamer]

Making a game plan while trying to work/finish a slab is a bad decision. If you could find a few people with a bunch of experience to help out all the better. I've done dog runs, small basketball courts etc= hard work.

 

[Bigblockyeti]

I'm getting ready to DIY a 16' x 22' shed slab @ 4" but no real weight to speak of, a future sub-compact tractor would be it at most. Local guys were quoting $700-$850 just to place concrete and power trowel. Guys in the hood finishing up the last few house slabs said $200-$250 for the same thing. I'm doing the excavation, compaction gravel, forms and future electrical conduit. The $2000 labor price seems high but not astronomically.

 

[ddurrett896]

I'd hire out the slab.

I have no issue with footers or anything broom finished, but finishing a slab smooth takes a lot of time and a crew to keep everything moving fast.

For my garage, I poured the footer and did the block then paid a crew around $2,000 to form, pour and finish 1,000 sqft. The slab takes some hustle - 2 guys floating with 2 or 3 guys behind them pulling and placing.

Easiest money I've spent...except the crane for trusses! Hire it out!

 

[Copymutt]

Recipe for disaster. Two guys and that many yards? Your going to have something other than a decent pour.
At a minimum, hire a crew w/ some experience.

 

[frankd]

Give my Guide to Floor Slabs a read for some thoughts on the process. Maybe you could do all the prep yourself and hire someone to do the place and finish. If you haven't poured a slab before, I guarantee it won't be flat or smooth when you are done. If that's ok with you, carry on.

Thanks I'll give it a read.

How old are you and your pops ? Concrete work isn't for the faint of heart nor is it going to be a piece of cake unless you're writing a check.

I'm 40 and my dads 70. But in great shape for his age. Probably because he spent his entire life doing manual labor.

After reading all the replies I think what I'll do is educate myself on the correct way to do this, do as much prep as possible, and then pay someone to do the pour and smooth it out. I'll just set it up for a weekend that he's not there and pay for it myself.

Thanks for the help!

 

[Terracar]

My dad tried the same thing - it failed miserably. It was 12-13 yards and it ended up ****. And my dad did concrete work 30 years earlier. Granted the mix was drier than it should have been, but it is physically demanding work. There were 3 of us (20, 27, and 50).


It ended up wavy and improperly sloped. While it is usable, it is clearly a DIY fail.

 

[Moose97]

I did an 8' X 8' flatwork (no beams) pad by myself. Ridiculous amount of work (used sac-crete) and the finish looked terrible. $2000 sounds like a pretty good price!

 

[RPH]

Concrete waits for no one. Without a experienced leader and a good crew this will get away from you. Next thing you know a mountain of concrete scrap in the yard. Check with other concrete contractors to get a range. I’ve done concrete work and it’s a young guys game.

 

[txvwnut]

I did the pour my slab which is 20’x26’ and took 27 yards. The OP’s slab if it’s just flat is 11 yards. If you have no experience with large concrete work DO NOT attempt this unless you have at least one very experienced person to help. I was fortunate to have two friends who both do/did concrete professionally and would not have been able to do mine right without them. I also had both my brothers, one who’s in the construction biz and the other who’s not but was an able body and willing to learn. There was also a couple or so friends who showed up to help plus my son and wife. All total I think I had 8 people with their feet in the mud at some point. If your planning on you and one somebody else it ain’t gonna happen that way and the truck driver will get pissed if your end becomes a fiasco. There is ton of work that has to be done right, before you even call the trucks in and if you don’t get it right you’ll end up with a disaster come the day of the pour. I also poured my driveway which is 175’ long and 11’ wide and took 25 yards. I did the drive with just four people, myself and three others, and really needed 2 more for this job.

 

[Jinks]

Just over 11yds. of concrete. I'll guarantee that two inexperienced people are going to have trouble keeping up with the truck getting that spread. Then, like LLWillysfan said "it's not going to be flat & smooth". Three or four inexperienced guys with a little information & study can do it & concrete isn't real complicated. Hell, I've done a few good jobs. OTOH, two experienced guys can make it look easy. Good luck with whatever you decide, & post some pictures of how it goes.

 

[Blue XJ]

$2000 doesn’t seem to bad, and worth the money. I received a few quotes for a 10x15 slab with a 18” rat wall around the perimeter, most were in the $15-1800 price range, and that’s about half the size of your job. My quotes included everything though, including hauling away of the grass they will be removing.

 

[frankd]

Thanks again for all the replies. Looks like I'm definitely not going to attempt the pour. We'll do the forms and spread out the gravel but that's about it.
Hopefully the guy that did our neighbors slab is still around. Contractors in upstate NY tend to be very flaky