Concrete Chairs

[paulsharvey]

Oh, one thing that some people don't know, but some accelerates used in cold environments and or "high early" concrete can attack the rebar. In theory, wire (i mean WWF, not #2 smooth rods) does nothing long term, once curing is complete; however, it does hold cracking concrete together better, and it's a son of a B when it comes time to demo it.

 

[newbury]

they could do it cheaply and come back in two/five/ten years and redo it, depending on actual usage, and degradation.

So if a contractor builds a road cheaply, and he is the only local bidder, then he can probably plan on coming back and get paid to do it again.

 

[paulsharvey]

Post tension down sides; the engineering, the cost of the cables, tensioning equipment, and a testing guy to document the pull force; and then once done; you can't just core or cut that slab. Now, I've ran a GPR on open ground/asphalt, looking for utilities, and maybe? you can GPR the cables in a slab, but if you have conduit, plumbing, HVAC chases in the slab, and how shallow the cables would be, I dont know if the cables would show on a GPR?

If you've never seen them, it's a cable inside a greased pvc sleeve, and once pour if complete, it is tensioned with a hydralic 'jack' and a split nut installed to hold the tension. It virtual eliminates cracks; and you typically don't saw control joints. They aren't just laid out willy-nilly, they are designed and spaced to an engineered plan. They Can float a bit in a pour, and I've seen where a cable was actually at the surface of the concrete, but it was in a tile area, so it was able to be hidden.

 

[paulsharvey]

Ultra runner fiberglass is significantly more expensive than steel. Only used in highly corrosive environments or where magnetic properties are issue

Even in most corrosive environments, cathodic protection is probably a better route than fiber bars.

 

[paulsharvey]

We did a 'lumber tree' at a conclusion supply house once; me and one helper; 10" thick on top of 10" limerock, #5 rebar mat, 3" up, then a WWF layer, then another set of #5 bars in top 3". All that, with fiber in the mud too; it was like a 36 yard pour each (2 foundations) and finish, and a pain in the butt. I think those two slabs will outlast mankind, but it was what the engineer designed.

 

[paulsharvey]

So if a contractor builds a road cheaply, and he is the only local bidder, then he can probably plan on coming back and get paid to do it again.

Almost anywhere, a road will have an engineered design, and an inspector to ensure they build it to spec, on any publicly funded project. Developer or private; most of them don't want to pay for the inspecting costs. Public, you have to think, your thinking 10/15/25 years down the road, for development, your only concerned with the 12 month warranty period, unless it's a developer who plans to keep ownership (the small minority).

When I was working on some 'shovel ready stimulus' jobs, building sidewalks to nowhere (that the county could never afford to maintain after the fact...) the concrete guys were telling me how; when they did house slabs, they would "move forward" the visqueen, wire, and rebar, once inspected; to the next house... there is a lot of shady stuff in the home building business.

If I left any doubt on what I meant by Move Forwards; they would take the rebar, plastic, and wire, after inspected and just use that in the next slab for inspection; and not use any when it was poured. I'll bet there's a neighborhood somewhere south of Ocala, where homeowners are arguing with insurance about "sinkholes" cause their slabs to crack, and foundation problems. These guys thought it was smart/funny, and where borderline bragging about it... I will admit to cutting some corners through the years, but never anything like that.

 

[paulsharvey]

Not concrete; but when I was an acting super, I had a job interview with a home builder. Interview, they said, take us step by step every process in building a home. Anyways, got all the way to drywall, and I stop myself, and say, 'crap I forgot to insulate'.
After the interview, I'm talking to a friend who was a Project Mananger, and told him about that. He say, that's not funny, we forgot to insulate a house one time at a previous company. I asked "what did you do". He say, what do you mean, we caught it too late, and never insulated it, someone is wondering why their power bill is 3x their neighbors.

 

[jjeff]

Geez, companies like that give construction workers a bad rap. Makes me grateful I never worked for companies like those examples and diy everything when it's time and cost effective.

 

[jjeff]

Worst thing I ever did working for a company was when I got taken off the framing crew (surgery, light duty) put on finish crew, finishing out a small closet putting ledgers for shelves on painted textured drywall, still had my framing hammer on my obnoxiously large tool belt put a nice hammer head sized hole in the drywall. That shelf ended up with about 1.5" closer spacing to the shelf above it and I considered it personally customized cuz of my bull in a china shop f-up.

 

[lilranch2001]

Did you go to confession after that?

 

[paulsharvey]

Professionally, I've never built a project I would be ashamed to admit I was part of. Now, I did do an apartment complex, of 16, 8 unit buildings; and everyone missed it, but building 7 never got the faux shutters, and I noticed it like a year or two after the project was done. We did another, where the "house" hose bibs where feed off one of the ground floor unit's meters (that was the design), and out of 16 buildings, somehow, one ended up with the "house" hose bibs on the Hot water... I've seen, but not been part of, accidently hot toilets. On an owners walk though, I caught where we drywalled over the AC grill in a utility room; we didn't point it out, But we did cut it out and install the grill when doing paint punch work.

I did do a indoor baseball training facility (metal ware house type building), that 'secretly' had a section separately that housed a drywall contractors business; inspector asked, Why is there a separate power meter, separately keyed doors, is this really a single occupancy? "Yes, the manager just doesn't want the kids/coaches having access to the admin part". If it was dual occupancy, there would have had to be firewalls, ect between the tenants; but the drywall company owner was the client, and he was partners with the baseball coach's business. That building also had like 10 ft ceilings on the interior walls; drop ceiling to 8 ft; but like a 28 ft peak in the metal building. They put 2x10 metal studs/rafters on the top, and inspector said "they don't plan on doing decked storage, do they, it not shown on the plans". I said "nope that's just to support the drop cieling". He knew what was up, but dropped it. Yes, they decked the top, and used it for storage once inspections were final. Same place, the client wanted the low flow shower heads and all removed as soon as inspections were final.

 

[paulsharvey]

When I did my shed, I put wire in the slab, even though I didn't pull any permits, and also added some scrap #4 rebar. Not that the floor is holding much, it's a pole building, and I poured the slab much later, so not structural.

 

[paulsharvey]

If the general public knew some of the things that go into construction, they wouldn't be happy. It's like watching hot dogs being made. I tell people, I don't care if it's low income housing, or a $7.5M Beach mansion, there is a Big gulp soda cup full of pea somewhere inside your walls. A drywall guy has pooped in your bathtubs, ect. Guarantee someone peed in the closet on the drywall, during construction... there probably was a water leak where drywallers screwed into a DWV pipe, and although repaired, there was untreated water damage on the backside of the drywall and/or insulation. Not uncommon for a electrician to have a short and trip breakers cause a screw/nail is in the romex, and they back the screw out, or pull the nail, so the trip to ground goes away, But that romex doesn't get replaced.

Ever function test a dishwasher that someone peed in? That's a smell for you. All of that is with some oversite, by people who want to do a good job. Imagine on some of these projects where 1 super is watching 20 houses, and doesn't even visit each one once per week.

 

[paulsharvey]

A pet peeve of mine, is throwing trash in a pipe ditch. Don't throw the pipe cut offs, mega lug kit boxes, ect in the dang pipe ditch. It seems minor, but 2 things; #1; years from now. someone is digging with a hoe, and has to stop and hand dig around each piece of trash, trying to avoid utilities; and #2; if you let them throw pipe cut offs/boxes/glue cans in the ditch; next thing you know, it's the pallet from the firehydrant assembly that gets thrown in there.

As for concrete, like a garage, where you have a form that gets pulled where the floor slopes out the door to the drive; some guys will just pound that down an inch or so, rather than pull the stakes/form during the pour, and you'll end up with a nasty looking 1-1/2" cracked/spalled area. Or where sidewalk, one pour stops, and you bulk head with a 1x4; and a lot of guys will want to leave the 1x4 when doing the next pour; rather then pulling it, and placing expansion joint. Looks like crap.

 

[4570Man]

A pet peeve of mine, is throwing trash in a pipe ditch. Don't throw the pipe cut offs, mega lug kit boxes, ect in the dang pipe ditch. It seems minor, but 2 things; #1; years from now. someone is digging with a hoe, and has to stop and hand dig around each piece of trash, trying to avoid utilities; and #2; if you let them throw pipe cut offs/boxes/glue cans in the ditch; next thing you know, it's the pallet from the firehydrant assembly that gets thrown in there.

As for concrete, like a garage, where you have a form that gets pulled where the floor slopes out the door to the drive; some guys will just pound that down an inch or so, rather than pull the stakes/form during the pour, and you'll end up with a nasty looking 1-1/2" cracked/spalled area. Or where sidewalk, one pour stops, and you bulk head with a 1x4; and a lot of guys will want to leave the 1x4 when doing the next pour; rather then pulling it, and placing expansion joint. Looks like crap.

One of my friends was putting in a water line and crossing a second water line. He’d located the line and dug around it by had. The next scoop with the excavator ripped the actual water line out of the ground. The pipe he’d hand dig around was actually a piece of scrap.

 

[jjeff]

Did you go to confession after that?

I just did lol

 

[dodge man]

So if a contractor builds a road cheaply, and he is the only local bidder, then he can probably plan on coming back and get paid to do it again.

Most public works projects have inspectors but not all. Most contractors want to do a good job but as quickly and cheaply as possible so they will cut corners if allowed.

I spent most of my time as a land surveyor but did quite a bit of time doing inspection. I didn’t like it. If something went wrong everybody blamed you.

 

[jmc]

I see your point; do you have any data/personal experience for chairs causing a stress riser issue? I don't do lots of concrete work, so I'm no expert, but I haven't happen to me or on a job that I was working on. (So, that doesn't mean much, but I haven't ever read that it is an issue, either.) If it is an issue, I wonder whether concrete chairs or plastic ones are better? IIRC: the concrete institute recommends both, but doesn't call out a stress riser issue, but my memory isn't that great...

All the best,

Peter

Nah, no experience with concrete. Mine was just a theoretical question stemming from design work in another industry.

 

[paulsharvey]

So, I guess I'll throw a little bit of defense at contractors; Let's say you bid a job, at a fair profit, and diesel goes up 30%; labor by 25%, asphalt by 25%, ect. You're looking at losing your butt, if you can't either get some price adjustments, or cut some corners (hopefully in non critical areas). Another issue, is, good times allow bad contractors to survive. Bad times, weed out the bad contractors, and everyone had to get back to fundamentals, lean/mean/efficient, and right on the 1st try.


Probably 16 years ago, had a PM mention the 1/10/100 rule. I asked what that was. as I'd never heard of it. He said, take a drywall guy; end of the day, he's cleaning his mud pan and knives, and see he missed a screw head; it costs him $1 to take care of it, it takes him a few minutes and clean up again. If the next guy (superintendent, painter, whatever) catches it, it costs $10; drywall guy needs to come back from another job or building, and it's basically a 1 hour job to fix a 30 second probelm. If it gets caught at the final owners walk through, it costs $100. Now you have to get the drywall guy, who has already left back, painter (who may or may not have left), maybe a cleaner, and schedule a 2nd walk though to verify it's done.

Now, roadwork, it's probably the $100/$1000/$10,000 rule. Case in point; a minor maintenance asphalt job, contractor working NB, various small 100 ft full lane mill and resurface areas; while cleaning up asphalt in the SB lane, the front end loader gouges the F' out of the SB lane. It would have sucked, but, if they just radio down, and tell the guys bring the roller, 2 tons od asphalt, and the shovel/lute guys down, I screwed up; maybe that's $1000, But they didnt; and it was found 2 or 3 days later, and they had to remob in, at a min cost of $5k.

 

[jjeff]

To most degree for me anyway if I'm putting time and effort into something I want to do it right within reason. For me anyway on diy building projects it usually takes longer with greater effort to try and make something look right than actually do it correctly, plus than it continuously will not bother me so I can sleep. tearing something completely apart and starting from scratch literally in my case. This was especially prevalent with a bathroom remodel on my previous 60 yr old house to put it lightly I wanted to install a bathroom fan on a Saturday many Saturdays later it was complete after rewwiring everything, running new circuits from the panel , installing new sewer amd water ines, new vanity, subfloor, tiled floor and bath, toilet, drywall, and hired someone to refinish my cast iron tub, lol.