Estimate for Slab

[Wao nahele kane]

DanielP,
Get off the crack pipe. Your buddies Beavis and Butthead are around the other corner.

[Rob Tucker]

It has been my observation that a well finished concrete slab is not a job for amateurs. I have seen jobs where friends volunteer to help and as well intentioned as they may be the completed job was a mess. A skilled concrete crew brings something to the job that has value. Quality of the finished product. Experience has value.

Once the concrete sets it is set. Dips and valleys and ponding on the slab might be acceptable for a garage or barn but it doesn't bode well for a home.

For those that have the skills and tools that's great. Most people don't. So I think that the proposed budget of $8 PSF is not unreasonable for a skilled reputable crew. It would be unreasonable for a jackleg job. Check references. Get competing bids. The larger the slab the more men will be needed to finish it correctly.

I also think that when budgeting a job you should be conservative, not optimistic. It is better to find out that you came in under budget than over budget when all is done.

[DanielP]

I believe that the request was for an estimate for the job to be done by others(Licensed Contractor required). Legally requiring materials, Insurance, wages and labor burden + OH&P assumed.

Retired GC. In the trades since '65

Ed to add: I would pass on fiber and go #3 rebar 12" O.C. if there will be any vehicles (tractor)in the barn.

Dan

[Seeb]

Most people don’t get the SKILLED part of Skilled Labor. Just because you can pickup a tool don’t mean you can use it. Good trowel men are worth their weight in gold, I know I cant do it

P.S. I have mixed 24 yards in 2 gas mixers but it was hellish, none of the crew could even pick their arms up the next day

[Wao nahele kane]

Yeah I know it’s straying off topic a bit, but this reminds me of something with regard to modern construction issues…

Seeb,
That's a lot if you loaded the aggregates by hand and not backhoe, I’d also assume there was no pump onsite either. In some remote locations, it's not possible to get a concrete truck to site from a batch yard and the portable mixers the only method available. In third world countries such mixing methods are common place and saw them used frequently when living in Mexico.
Our innovative thinking in this nation in some respects has suffered via too much convenience. Consider in-ground pool construction, how would one fabricate a concrete pool or cistern if they had no shotcrete/gunite machines or forming materials available? I’ve seen it done and it’s a very simple method resulting in no joints.

Dan,
In my experience for a slab on grade, the mesh/bar requirements are dictated by the sites soil substrate and weather exposures, not necessarily just the load atop them. In this area, soft soils are not always the case, more often we end up with crushed compacted rock atop larger ripped and rolled rock. There's not much stress applied to a slab on grade when sitting atop such "soil"/substrate. I’d let an engineer decide what’s necessary.
Also... I’ve built several multilevel concrete parking garages over the years within several mid high rise buildings; those included multiple PT slabs above the basement parking level. The pads on grade within them were nearly all chopped fiber mesh with no rebar specified in them.
E ho'a'o no i pau kuhihewa.

[OpenD]

"Our innovative thinking in this nation in some respects has suffered via too much convenience."

Agreed. I've seen the dry components for concrete mixed on a canvas tarp, then wet mixed in a flat wood and sheet metal tub using a mixing hoe, then hand troweled onto a rebar and mesh frame to create a 4,000 psi thin-film ferro-cement structure that will withstand a direct hit from a Force 5 storm without damage, and will still be standing 200 years from now.

There are all kines innovative thinking being used in other parts of the world that we Americans are too arrogant to consider, even though the ways we have been doing things for so long are not necessarily the best or wisest. Wait, that was overly polite. Take 2: Our thinking is bankrupt. Yeah, that's what I meant to say.

Just to start with something obvious... in the post WWII years, a 1,000 sq ft house with 2 BR and 1 Bath was considered normal for a family of 4. And all over the Volcano area, where I live, such residences are still in use, many of them built pre-WWII. In contrast, in developing nations today, a house 1/3 that size is considered adequate. Let that one sink in.

But here, today, you would have difficulty even obtaining a permit to build a residence that way, despite the fact that there are perhaps 20,000 people in Hawai'i, according to Gov. Abercrombie's staff, who do not have a solid roof over their heads. None at all.

Seriously, we need to re-examine all this stuff, and take it down to the bones, before we lose the chance entirely.

China is well poised to eat my grandchildren's lunches, as well as yours. Pouring the biggest slab you can using amateur labor may be the stupidest thing you could do. Pouring the smallest slab you can deal with, using a professional crew, could be the smartest. The key thing is to stop looking at (anything in terms of) how it's been done before, and really consider what is smart as of today, with all we know.

OpenD