New concrete decking....what gives?

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This is from cement.org regarding sawcut joints:

Joints may also be sawed into the hardened concrete surface. It is important to understand that the longer sawing is delayed the higher the potential for cracks to establish themselves before sawing is complete. This means that any cracks that occur before the concrete is sawed will render the sawed joint ineffective. Timing is very important. Joints should be sawed as soon as the concrete will withstand the energy of sawing without raveling or dislodging aggregate particles. For most concrete mixtures, this means sawing should be completed within the first six to 18 hours and never delayed more than 24 hours. Early-entry saws are available which may allow cutting to begin within a few hours after placement.
 
ouachita said:
This is from cement.org regarding sawcut joints:

Joints may also be sawed into the hardened concrete surface. It is important to understand that the longer sawing is delayed the higher the potential for cracks to establish themselves before sawing is complete. This means that any cracks that occur before the concrete is sawed will render the sawed joint ineffective. Timing is very important. Joints should be sawed as soon as the concrete will withstand the energy of sawing without raveling or dislodging aggregate particles. For most concrete mixtures, this means sawing should be completed within the first six to 18 hours and never delayed more than 24 hours. Early-entry saws are available which may allow cutting to begin within a few hours after placement.
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That is a little disappointing. Arguably, this could have made a difference.
 
Having been a victim of shoddy work numerous times myself, I can sympathize with you. This is why public works contracts are very long and very specific. The private homeowner may get burned once in a while, but a public entity that does construction every day learns fast. A contract for a concrete job should specify things you would think are obvious, but may not be done if not specifically called out in the contract.

Some points I might want in a contract would be:

  1. The finished deck surface should slope away from the pool so that water on the deck doesn't drain towards the pool or coping joint.
  2. The finished deck surface should be free of depressions or flat areas that cause water to puddle or stand in any area.
  3. The deck should be reinforced with a rebar grid positioned within the slab (as opposed to the bottom).
  4. The deck should be poured with control joints (how many depends on the job).
  5. Penetrations and joints should be sealed to prevent water from getting under the deck.

Does your contract have any language specifying the quality of the finished product?
 
The swirl marks are from troweling the edges at a different time than the field. Every time you trowel, it's a slightly different color so mason should hit everything from one end to other, not field first and edges later or vice verse. Concrete has a lot of water in it (30 gallons per yard). As the water evaporates, the concrete loses volume (shrinks). This shrinkage makes it crack, like mud cracks when it dries. The wetter the concrete is poured, the more volume it loses. All concrete needs control joints or you will have random cracking. The ACI guideline is 2-3 times the depth in feet. If you pour a 4' slab, then joints are recommended every 8-12 feet. For the record, most shrinkage cracks form in the first 24 hours. That is why joints need to be tooled in wet, or machine cut within the first 24 hours. Wet curing is best because it slows down the evaporation but you cannot wet cure colored concrete because it will cause efflorescence. All concrete bleaches lighter when dry. You can use a solvent based sealer to get the color when wet, but that adds maintenance. I prefer siloxane sealers around a pool which provides a natural look vs shiny, wet look. BTW, rebar should always be on chairs so it is in the middle of the slab or at least 3' off the subbase, and 3' from surface in deeper pours like inside your new pool.
 
When I had my pool done, I found out that rebar was not part of the cost. They wanted $1/sq ft for a 30x30 rebar grid. They said that it was not necessary in my case because the concrete had fiber mesh in it. I decided to go ahead and do my own rebar on an 18 x18 grid for a cost of $0.36/sqft. I put them on dobies that were 2" off the ground. When they went to pour in the concrete, the guys just stepped on the rebar during the pour so it was on the bottom. I had to constantly remind them to pull up the rebar. BTW - when they were pouring, I check the concrete, and I didn't see any fiber mesh. The concrete guy told me the fiber were small, so I wouldn't be able to see it. (I wonder if he lied to me about fiber mesh.)

With that all said - I learned a few things. Many construction guys are there to get the job done as quickly as possible so they can go to the next job and earn more money. Also - if you can't see it, they may cut corners. You'd be surprise how many front doors I have replaced where they didn't put insulation in the gap between the rough opening and the door frame.

For my pool build, I worked from home most of the days that something major was happening. And if I saw something wrong, I would ask them to correct it.
 
diverminh said:
With that all said - I learned a few things. Many construction guys are there to get the job done as quickly as possible so they can go to the next job and earn more money. Also - if you can't see it, they may cut corners. You'd be surprise how many front doors I have replaced where they didn't put insulation in the gap between the rough opening and the door frame.

For my pool build, I worked from home most of the days that something major was happening. And if I saw something wrong, I would ask them to correct it.
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That's a good practice. Where I work we have construction inspectors on the job site any time a major step is taking place. I can tell you from experience, if there's a corner to be cut someone will cut it if they think they can get away with it. We've made contractors demolish thousands of square feet of concrete because they did a pour without an inspector on site and we couldn't verify the type of rebar used (turned out they cheated on the grade of rebar). The contractor was willing to risk a $100,000 pour to cut corners, so that contractor would have no problem cutting corners on a "tiny" residential job.

The unfortunate part comes when the work involves a trade where they may be cutting corners, but the customer could be watching and not know what's happening. This is why it helps to have a good general contractor. They are supposed to supervise the subcontractors/tradespeople. The responsibility for the job rests on them. If you really want to make sure nothing bad happens, hire an independent inspector to be present when work is taking place or to inspect the work prior to payment.
 
did you withhold final payment??? no way I would pay him at this point. you still have to put control joints and construction joints in concrete that has fiber mesh. that's absolute hog wash. do not accept it if you are not happy. do not give them final payment until you are happy. put your foot down

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ouachita said:
Fibermesh is garbage. A good rebar grid is the way to go. I'm surprised fibermesh is still used.
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its cheaper, both in materials and labor costs. but I agree with you. this GC's work is poor to say the least
 
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