Slab poured over saturated ground

[Massive Overkill]

It had been raining for about a week straight before the weather had started to let up. The plumbing was put in the ground and then more rain. They placed the vapor barrier which saw some flash showers, but overall two days passed and then the slab was poured.

Only one day had passed since the pour and a loader loaded the concrete block shipment onto the slab. There was a blowout in the slab and in the hole you can clearly see/feel water trapped underneath the vapor barrier in that spot.

Now, I know this can be fixed, but what worries me is the possibiliity of either other water pockets or air pockets underneath the slab. I've taken video and forwarded it to code enforcement who put a temporary halt on construction until the architect/engineer can propose a solution.

Are there any tests (other than tapping the concrete with a metal/wooden rod and listening) that can be done to locate other compromised areas under the slab? I want my house done right but cringe at having to have the slab broken up and repoured (fibermesh btw.........stemwall construction with floating slab..........stemwall was done in dry weather).

Here is video of the conditions before and another video of the hole. I'm sorry I didn't come here first, but went to CFOT (if you're a member there you know what I'm talking about). Anything flies over at CFOT, but please, I only want profossional opinions here and yes I've been ribbed enough about the traffic and housing cost. I don't need/want opinions about that, only the slab please. Thanks.

Links to video:

Hole:



Conditions before the pour:

 

[Fast Orange]

I see a jackhammer in somebodies future.I wouldn't accept anything less than a complete demo of the slab and a repour.You'll probably wind up digging out the bulk of the mud and putting in gravel.

 

[Massive Overkill]

I take it you're in the business/contractor and this is a professional opinion. What ammunition (other than the video) can I take with me to validate that the whole slab needs to be repoured. Obviously it would have to be proven that the rest of the slab is at risk.

 

[bluesman2a]

I had something very similar to this happen. When they poured my pad, there was too much water in the concrete (on top, instead of underneath). They worked it for a good 8 hours and it still wasn't dry. The finish was horrible and it started spalling in under 3 days.

Long story short, they came out, tore the whole thing out and started from scratch. On THEIR dime. I wouldn't accept anything less in your case either.

 

[GeorgiaHybrid]

Massive,

Several things wrong here.

1) The fill should have been compacted.
2) You should have had at least 3" to 4" of gravel on top of the fill for drainage
3) The slab should have NEVER been poured with that much water INSIDE the stem walls.

You will never be able to tell without a demo of the slab just how bad the problem is. Once the water level does go down, that is when your problems will appear. The fill will settle and not fully support the slab. By the way, how thick IS the slab at the hole? It appears to be about an 1 1/2 thick. What was spec'd?

Either way, it needs to be fixed and the easiest way would be to demo the slab, let it dry out and re-pour. You could also drill holes and pump under the existing slab once it dries up but that will take a while with the plastic and slab in place.

 

[Massive Overkill]

The walls are already up but second floor framing hasn't been done due to the stop-work order. I feel like telling them sell this house to someone else and build me another one on another lot. Does anyone know if there is some sort of ultrasonic test or some other test to determine if there are gaps between the slab?

 

[Massive Overkill]

Massive,

Several things wrong here.

1) The fill should have been compacted.
2) You should have had at least 3" to 4" of gravel on top of the fill for drainage
3) The slab should have NEVER been poured woth that much water INSIDE the stem walls.

You will never be able to tell without a demo of the slab just how bad the problem is. Once the water level does go down, that is when your problems will appear. The fill will drop and not fully support the slab. By the way, how thick IS the slab at the hole? It appears to be about an 1 1/2 thick. What was spec'd?

Either way, it needs to be fixed and the easiest way would be to demo the slab, let it dry out and re-pour. You could also drill holes and pump under the existing slab once it dries up but that will take a while with the plastic and slab in place.

Quote from code inspector after I asked him about it:

"Yes we do get a compaction report before we approve the slab to be poured."

If they pump under the slab, how do they keep the vapor barrier intact?

Should I also be pointing fingers at code inspection for letting this happen?

Oh yeah, the slab feels pretty thick actually. The area immediately around the hole is sort of thin, but if you follow it down and under it gets pretty thick, I'd say 5-6" from what my hand would fit in.

 

[GeorgiaHybrid]

What was the compaction percentage? 95% or better?

They can pump under the slab but the problem remains as to how long it will be before the water dries out and the fill settles. There will be more than one hole to pump the concrete in, sometimes the vapor barrior will remain intact but then again, **** happens and the next hole might rip it. If the new concrete goes under the barrier, it is not usually a problem with the stem wall foundation you have.

If this was just a slab on grade with integral footings, I would be more concerned about water at a later date. Stem walls act like a "swimming pool" and do a good job of keeping water out from under the slab. They also do a good job of keeping water under the slab if the fill is saturatated before the pour.

Your call but I would have it re-done at my cost if no one else will side with you. The slab is one thing that is very difficult to fix once the house is up. Either that or find another house if this is in a subdivsion with multiple houses that you can purchase.

 

[Massive Overkill]

As soon as I get the report I'll post it here. From what I've seen of the other houses, the construction quality has been good, I just think a bad judement call was made on mine. I'm going to see if they'll build me on another lot at their cost or re-do the whole slab. One thing is for sure, they're going to eat all costs no matter what.

 

[akdiesel]

I am not in the cement buisness but have done jobs before and have a couple of concerns that may help as well.
With the underlayment being installed in wet conditions while the soil has been saturated wont that trap the moisture in the soil and not allow for a drying time?
As mentioned Georgia, it looks like there was too much water in the mix at first and that would be the reason for the blowout. Contact the cement company as well. Isnt the normal call for slump 5"?

Good luck.

 

[Massive Overkill]

Thanks for all the help guys, especially Georgia. Construction supervisor hasn't called me yet (supposed to call me today).

 

[GeorgiaHybrid]

Let us know how the call goes...

 

[independentrider]

I take it you're in the business/contractor and this is a professional opinion. What ammunition (other than the video) can I take with me to validate that the whole slab needs to be repoured. Obviously it would have to be proven that the rest of the slab is at risk.

Have the code enforcement guy write a letter stating that it must be demolished.

 

[slicktoptt]

Is this a Maronda home? Based on some things you said in CFOT I get the impression that is who is building your home. I used to work for them in Jacksonville. Where are you in FL?

Don't have much more to offer that hasn't already been said. I would not accept that house without an independent engineering sign off and an extension of the builders typical 1 year warranty.

Good luck.

 

[Massive Overkill]

I would rather not say who the builder is until there's a resolution. Construction manager called me, but the call was very brief. I'm going to talk to my salesperson and re touch face with code enforcement. Sending you a PM.

 

[lilcuda]

I'm no expert by any means, but I did get kinda screwed by a shady contractor on my garage build. He took lots of shortcuts, used inferior materials, etc.

Anyway, the one big lesson I learned is that building something to code does not mean it's good quality. The only thing the building inspectors are concerned with is liability. As long as it doesn't fall down and hurt or kill someone, it's good.

You have to be your own advocate for quality. Don't settle for lower quality than you expected going into this. I let my contractor slide on a lot of stuff and I wish I hadn't now, but it's too late.

Good luck!

 

[Massive Overkill]

Slicktoptt, thanks for the info.

Let me know if you guys agree with me, listen to the echo off the walls:

 

[Nealcrenshaw]

Listening to that,i would walk away from this, that entire slab has to be demolished.
Dont risk it.

 

[GeorgiaHybrid]

You already know what I think....

 

[Massive Overkill]

You already know what I think....

Yep, but do you think my latest video adds fuel to the fire or doesn't prove anything at all? I'm trying to gather as much valid ammunition as possible.

Also, now that the walls are up, are they going to have to come down to re-pour the slab? Is there any risk to damaging the stem wall if the slab is demo'd?

 

[GeorgiaHybrid]

To start with, the code inspector only checks to see if the fill has been compacted to the proper percentage. They do not care what happens after that and in this case, it was checked and then your contractor poured the slab after a week of rain. He is the one with the problem.

Talk to the contractor and see if he will make this right to start with. Don't go nuts and start screaming at him but just be calm and ask what he is going to do. You might be surprised by his answer by pointing out to him the hollow sounds from some areas in the slab.

If he says that everything is fine, ask him if he minds if you get a second opinion "just to be sure" about the condition of the slab. When he agrees, make sure that you tell him that you will pay for the inspection if everything is OK but that you expect him to pay for it AND correct the problem if anything comes up. If he starts to balk here, you have a problem and need to stop and get some advise about your options (read "talk to a lawyer").

 

[BLUETAILFLY]

If you havent closed on the final deal you have them by the short hairs..I had a sloppy construction issue with a house I was having built. I took some pictures, described the issues and in your case send a leter from an expert saying "This if not fixed could jepordise the sale" and send it registered... Believe me heads will roll and it will be done right becaue too many people are feedin off of the same tity ...Your leter documents it.

 

[Massive Overkill]

Thanks guys, I've kept a calm head throughout the discussions and early indications are they want to make me happy. What about my previous question (I edited my last post):

"Also, now that the walls are up, are they going to have to come down to re-pour the slab? Is there any risk to damaging the stem wall if the slab is demo'd?"

 

[nissan_crawler]

I'm by far not an expert on this. I would think it *could* be done without damage, however...I think it would add so much difficulty they will probably take one wall down at the least, just for access.

I'm really freaking floored they would try that **** in the first place. I would be fit to be tied. Personally, I would give them two options, hammer it all out, and start over, with NO new progression of work until I approved each level, or I was walking.

I.E. demo slab, me inspect walls. Gravel, compact, me inspect. Vapor barrier, me inspect. Pour, me inspect. If they don't like it, f'em. They are not to be trusted after this.

 

[bmwpower]

The walls are supported by the footer, not by the floor. There is a footer, right? They should be able to pour the floor without messing with the walls. Only concern would be what nissan said...access. But if they really had to they could pump it over, but I'm sure they can find a way to move the concrete around on a new pour.

 

[Massive Overkill]

The walls are supported by the seperately-poured stemwall (I'm a noob at construction terminology, sorry). Wasn't too sure if when they break up the slab if it would have bonded to the stemwall and possibly damage it in the process.

Here's what we're working with for access:

 

[akdiesel]

If you have problems with the slab you may also have issues with the footers and possibly the morter that holds the blocks together, this is assuming the concrete came from the same location and transporter.
You can get a lot of info from the this site http://www.concretenetwork.com/

 

[Massive Overkill]

If you have problems with the slab you may also have issues with the footers and possibly the morter that holds the blocks together, this is assuming the concrete came from the same location and transporter.
You can get a lot of info from the this site http://www.concretenetwork.com/

The problem wasn't with the mix but with ground conditions when the pour was done. Thanks for the link.

I've talked to my sales lady. They are going to do whatever it takes to make me happy. That includes building a new house on the more expensive lot at the same price ($40k premium normally). My sig. other is kind of set on this lot (yes, even with the traffic noise, which you can't hear from inside) so a re-pour at the very least if not a complete redo or a new house on another lot.

They are having their engineers as well as an outside engineer inspect the slab and I've already informed her that the whole slab will have to be done at the very least, which they will do even if by some reason both engineering inspections come to the same conclusion that it can be repaired (which I highly doubt).

I can also walk away and get my money refunded in full. That's the last option we'd take.

 

[Heiny57]

Just a thought here, but was the Termite spray done before or after the rains.

It could be bad also.

 

[thammel]

I would definitely go for the more expensive lot, especially if they are willing to do anything to make you happy. I wondered about the proximity of 1) the road and 2) the pond behind you. Remember that location is everything re housing and if you get a better location at 40k$ free, go for it. Talk the wife into it. Tell her they'll never be able to make the current build ok.

Tom

 

[slicktoptt]

I would have a sit down with the sig. other and explain to her that the risks out weigh any attachment to that particular lot. You have an opportunity to wipe the slate clean on a more expensive lot. I would take this option in a heart beat. The sales lady would not have even completed her sentece before I said YES! My wife/girlfriend would have to get over it. If you do not take this option you run a very high risk of kicking yourself later.

That slab is going to sink and separate from the stem wall. Even with a repour there is no guarantee it won't separate. My old house had a stem wall and floating slab and when we had the carpet stretched we noticed the slab had separated and settled about 1/4" to 1/2" from the stem wall.

This can lead to tiles cracking, walls cracking at the joints, doors not closing correctly, or perhaps if it settled enough it could crack the pvc plumbing.

Maybe they can tear out the slab and repour it but are you guaranteed it is going to have the same structural integrity as one that was done correctly the first time? I guess my best analogy for this would be a pretty well wrecked or totaled car. Sure, you can fix it but there will always be something about it not quite right. Would you buy a car if you knew the frame was bent and repaired? Consider the slab your frame.

 

[GeorgiaHybrid]

Massive,

The floor can be removed if care is taken, the stem wall drilled for stubbed out rebar into the new slab and a new slab poured once the underlying problems are fixed (mud out, good, DRY fill in place, gravel and good compaction, vapor barrier and termite treatment. All that being said, if they have offered you an upgrade to a $40,000 better lot at no cost to you other than a the additional build time, jump on it. Just make sure that you watch them or hire a house inspector (at your cost) to watch over them during the major structural, electrical and plumbing milestones on the project.

You could afford to spend the money on a “per visit” basis from a licensed inspector due to the upgraded lot alone. The maximum out of pocket for the inspections would be $1,000 or so (in this area) and would go a long way to keep the builder honest and your blood pressure low. It is basically a $40,000 return on a $1,000 investment. Try getting that in the market right now….

You just need to convince the SO that this is a good, sound financial move given current market conditions. The housing market will come back and that premium lot will make a huge difference if you ever decide to upgrade homes later. Tell them to think of it this way, if the lottery sent you a check for $40,000, would they send it back because it was green and not a pretty shade of blue??? I know that around my place, for a free $40,000, I can learn to love a LOT of ugly things….

 

[benjamming]

slicktoptt,
Huh? Why can't you repour a slab to perfection?

 

[Underdog]

Sure looks like its somewhere near here. As for gravel under the slab never heard or seen anyone use it. Normal building practice is clean compacted fill with a plastic vapor barrier on top then 6x6 10x10 wire mesh now fiber, concrete. House slabs built here are elevated on a pad of fill and all water is drained away to the side, front, back swales.

 

[slicktoptt]

slicktoptt,
Huh? Why can't you repour a slab to perfection?

I'm not saying you can't. I'm saying maybe you can. I'm no engineer but I would be concerned about them compromising the structural integrity of the stem wall and the erected walls when they bust out the old slab. I could easily see them put a jack hammer or bobcat into the stem wall or into the exterior wall and crack it. Where does all that water trapped inside the stem wall go when they poor the slab? My guess is it's going to forced to the edges and then out under the retaining wall. If it is forced out by the weight of the slab, perhaps there could be voids under sections of the stem wall as well.


Just too much risk involved for me when they are offering a much better solution of rebuilding him a new house. Only way I would accept a slab repour is if there were no other alternatives available, i.e. last lot, unique lot, my own personal lot.

It sounds like they are offering him an excellent "do-over" option that eleminates all risks for him and even includes a benefit. It would make absolutely no sense not to take advantage of this option.

 

[GeorgiaHybrid]

Underdog,

Are the homes near you using a monolithic pour with the foundation and slab poured at one time? That is what I see when the slab is poured on just an elevated pad. Around here, a stem wall approach with a floating slab will have a gravel base to prevent any frost heaves or water infiltration. The stem walls are poured (sometimes at the same time as the footing) and the slab poured at a later date with an expansion joint between them. I understand that most of Florida is sandy and warm and SHOULD drain well but in this case; it has not possibly due to the soil being oversaturated by prior rains. Either way, he has a problem with the pour that needs to be addressed before going any further.

 

[Massive Overkill]

My sig. other is cursing you guys right now, but she understands and I really appreciate all the help. I pretty much want to go with Georgia and Slicktop's recommendations and either bulldoze the entire site, recompact, and rebuild, or go with another site.

This house is the first in the subdivision and I'm sure they could demo it pretty quickly, but I don't think that would instill alot of warm fuzzies into perspective buyers coming in, nor the current homeowners in the community.

I don't suppose since the mortgage company is owned by the builder that they could lock me in today's rates?

Sure looks like its somewhere near here. As for gravel under the slab never heard or seen anyone use it. Normal building practice is clean compacted fill with a plastic vapor barrier on top then 6x6 10x10 wire mesh now fiber, concrete. House slabs built here are elevated on a pad of fill and all water is drained away to the side, front, back swales.

Pretty much how it was built. So concrete footings were poured about 1-2' below surface and then 2 layers of block built up onto that to create the stem wall. Integral footers with rebar were placed where the center and garage walls would have gone up. Plumbing was put in next (I've seen other homesites in the division get concrete wood framing done first, then plumbing, and finally stemwall). Vapor barrier was put down, swales on two sides were dug out to drain, and then fiber mix poured even with top of stemwall. Walls were done last.

Rainy season is almost gone so I guess I won't have to worry about it ruining my slab or roof (saw one roof get drenched before they could get tar up.....some things just can't be controlled.....that roof was warped).

It's going to take about 1-2 weeks to get results back even though my mind is made up.

UPDATE: Went back tonight. They took three core samples (one in the existing hole), slab was about 8-9" thick. They took the core samples near the edges of the foundation. Those places I pointed out with the sound test........one is already cracking, the other has formed another hole, just waiting for the concrete to be picked up out of it.

 

[Massive Overkill]

Engineering results came back which showed parts of the slab OK, other parts were not (pretty obvious huh?). Construction manager said he didn't want to take any chances and is going to have the slab completely torn up, despite the engineering results showing that it can be partially repoured/repaired. He did apologize for the mistake, stating he was on vacation (It was Labor Day weekend)and I guess who was left in charge shouldn't have been, otherwise the slab woudn't have been poured in those conditions.

They are going to cut the slab 2' from the stemwall and break it up (not front or back porch, just within the stemwall). . They are hoping once that is out of the way the remaining 2' will come away without any problems, but if it won't come out, then they'll stem the 2' section, and repour, filling in underneath the 2' section. Before re-pouring plumbing will be redone, termite retreatment, ground compaction, and new vapor barrier.

They are doing this even if I decide to build on another lot, which is nice to know that the next homeowner won't get screwed. I was misinformed/miscommunicated about the upgraded lot. They'll give me another lot, but not the premium lot (fat lady hasn't sung yet though).

I'll try and take video after the slab is torn up and just prior to the re-pour and make my decision after the re-pour has set on whether to start over on another lot or stick with it. The ground at this site dries pretty quickly and sets in hard, just what I've noticed from walking around the site, so I'm confident that the ground will be solid during the re-pour as fall is approaching and the normal daily torrential downpours are subsiding.

 

[Coach James]

Personally, if this lot is near the entrance to the subdivision, I would opt for a better/bigger etc lot closer to the back. Glad they are willing to make right on the screw up without you going to court or calling in a hitman.

Coach

 

[Massive Overkill]

Don't know if I'm boring you guys, but the slab has been removed; stemwall looks unharmed: