Concrete advice needed after the fact.
I’m a Remodeling General contractor in the Pacific Northwest. Current project is a vertical addition over the existing two car garage and a couple more garage bays added. My concrete and excavation sub started the job with adding foundation and footings for the new third bay 13’by24′. He then poured the interior slab and finally the approach. All in the span of around 5 days. Temps were getting low and it was 33 on the day he poured the garage slab and likely the same when he poured the approach. For the month following during framing temps were in the teens and around zero at night. We got a melt down here two weeks ago and noticed the slab cracked and heeved in the center the approach has one corner that fell off about 1″ where it cracked. I am now stuck trying to sell this to a client who does not want it and I believe rightly so. My concrete guy doesn’t want to stand behind it one bit and I am wondering if I am supposed to accept his rational the it would have happened no matter what to any sub.
He brought in gravel, he compacted it. No saw cuts were made. No reinforcement was used. No blankets were in place after the pour. Any thoughts on the subject would be greatly appreciated. I have had two other concrete guys come take a look and nobody wants to stick their neck out there and say they could have done it better. I am just trying to gather unbiased opinions to try and educate myself so I can sell the finished inferior product.
Dave
SHS Remodeling
Replies
its not the concrete but the subsoil. uncompacted. the concrete crack because it was weak or retarded due to cold weather. the settlement or drop of one inch is uncompacted subsoil.
You could not sell it to me either, jack hammer and redo.
It's pretty bad clay onsite and I know he was a bit concerned about that since he hauled out two dump truck loads of the stuff and replaced it with gravel. Which was then plate compacted. I believe it was freezing at night and warming up in the day so it's very arguable now what the ground was like at the time of the pour. Hindsight is always 20/20 and it's real easy for me now to kick myself for going lowest bidder on this one because I definately got what I paid for. That said I do need a solution that relies on expert advice since it may go to court to get his bond to pay. I need to be absolutely confident though that a new pour won't do the same darn thing after jumping right on the side of my client which is where I normally gravitate.
Regards
Dave
When a dumb kid, poured part of my own driveway 30 years ago on a 35 deg day when temps were supposed to stay above freezing for weeks (Seattle area). On hardpan, so no frost heave.
However, it unexpectedly dropped to very unusual 25 F that night, the fact of the concrete freezing that night during the cure made for a very soft surfaced 'concrete', and it was time for the backhoe with thumb. Even had layer of newspaper and cardboard over it. Expect there was not even a hard freeze, just enough for the concrete surface to have some ice crystals form.
Dave,
There are many things that must be done right, especially in freezing weather. I can't know what wasn't done, but from your description, I suspect that he poured on frozen, IOW, heaved, ground and when the thaw hit the frost heaving subsided. And probably 'forgot' other things.
BB's right, time for the jackhammer. And a new sub.
Have a concrete test outfit come out and core and test and analyse the 'crete. That'll give you some ammunition when you sue the heck out of that idiot who thought, "Hey, it's concrete. Pour it in place and it's done. Oh, BTW, it's concrete, it's garunteed to crack." Freakin' mud apes.
"I am wondering if I am supposed to accept his rational the it would have happened no matter what to any sub."
It wouldn't have happened to either BB or myself. It would have cost you a bit more a month ago, but a whole lot less than it will now.
SamT
Chances are pretty good that Brownbagg and SamT are right. But I didn't post to add to your misery.
Assuming that the concrete sub has not been and won't be paid, you might not be out that much if only the exterior slab failed.
If you have to pull that concrete out you might be able to save yourself a bunch of time and money using a small excavator with a thumb.
I pull up a lot of concrete. If the slab has no steel in it, you will use more time to bring a 3.5 or 4 ton excavator and a skidsteer to the site than it will to do the job.
A jackhammer on the other hand makes for a nasty day. Hopefully no need for that.
Good luck.
Just curious, is there rebar or wire in those slabs?
david, if I read him right ,he said there were no reinforcments used. Also, Im thinking at this point he's framed out.
You right..shoulda, woulda, coulda's are no help right now..The existing slab has to be removed. The gravel should be removed as well. You can get an inspection agency to come in and test the subgrade for compaction. They will use a nuclear density meter to determine the compaction. You want at least 95% compaction or 1.5 tons/sf bearing capacity..
Then put your gravel back in and compact that..then a vapor barrier and then the slab..Do the plans/specs call for reinforcing wire?..something like 6"x6"x1.4 WWM (welded-wire-mesh)..and if the pour is in colder climates..use an admixture..hot water in the mix and/or Super-Plastizer so that the concrete sets up faster...and ask that thermal blankets are used over night...
These are items that are the norm for this work..So when and if you do go to court 1. you're confident as what should have been done, and 2. you had it replaced correctly and not asking for the world as restitution.
Also, consider that by pursuing this course, you're relationship with the owner will be strengthened as they will perceive that you are truly working in their interest. Worse thing to have a client that doesn't trust you..
Hope this helps..
Edited 1/11/2006 12:17 pm ET by MJLonigro
Thanks for the responses on the subject. I definately agree that I need to take the homeowners stance on the subject and back them up completely. Had a conversation with the owner about it today since I've been keeping them abridged of the situation as it's transpiring so they know that I'm not trying to hide anything. He said while its obvious that the slabs have settled down now after things have thawed a bit it still is cracked and heaved in the center of the garage bay. The garage door was installed today and the guy could not get the thing to seal acrossed the obtuse slab. I am most likely head for a bond claim on this but will have to give the guy one chance to fix it right before making the claim. Now the fear is that he actually tries and it looks like isht again. On the advice of my insurace agent I will have further correspondence with this sub via certified mail and I am making all these moves known to the client so that they are in on the loop. I get the feeling the client is doing a bit of thier own research since he said today that rebar and blankets probably would have been a good idea. Not something a medical salesman normally says.
Any further response is greatly appreciated.
I am not understanding the heave in the center of the garage. If the temps were only low for a short period then frost heaving isn't an issue. Could the edges be settling instead? Because compaction certainly seems to be of concern.
Temps were low for a month of miserable framing. The cracks and problems were found during the recent melt down. It's now been around 45 days since the pour.
I'm going to take pictures tomorrow and if I can figure out how to upload them it will be a bit easier to talk about.
Regards
Dave
Dave,
Perhaps the best course of action right now is to send the concrete sub a letter stating that you want him to return to remove and replace the slab properly "in an effort to avoid any further legal action"
That line usually gets people's attention. If he refuses, your only alternative is small claims. You stated that you do not have a contract with the sub. Do you have any signed documents with him? Maybe an invoice or a proposal that's initialed?
Unfortunately, you have to do the right thing, costly as it may be, as far as the HO is concerned. He does have a contract with you I assume. So he is expecting a structure "free of defect." And it sounds like he is doing his homework. Nip that in the bud now or you will be going down a slippery slope. HO will start second guessing all of your quality and the next thing you know, you will be in litigation fighting for your hard-earned money (experience talking here!)
I have been through arbitration, and default of sub contractors with bonding company involvement. So feel free to ask any questions..
By the way, how did the plans call out the slabs? Did they just say "concrete slabs?" or did they call out any thinckness, psi rating, anything? IF not, then go after the architect's E&O for some restitution. Means and methods are the responsibility of the contractor, true. So it would be up to you to determine the best method to pour, ie blankets. But if he did not call out for re-inforcing, then some blame/cost is his. Give it a thought.
Mike
Edited 1/12/2006 7:27 am ET by MJLonigro
Edited 1/12/2006 7:28 am ET by MJLonigro
Not my bond. His!
I do understand your point however that bond rates are based on the number of claims made but thats why we make sure the other guy is bonded to protect against shoddy workmanship that he won't stand behind.
I'm not so excited about forking over the 7K required to do the job right before I make sure the guy knows that is the avenue that can be taken.
I would think your case is very strong, IF you have a signed contract with the sub indicating his scope (including the base prep), and the plans call for what is really needed. You will need at least that, plus an expert witness report of the defect. If the plans do not call for steel, and it is only now that you determine steel is needed, he'll probably walk. I would expect a difficult battle with the bonding company. You are not their customer, they have no reason to make you satisfied. It will not be like making a fender-bender claim with your friendly auto insurance agent.
On one occasion I threatened a guy's bond, a roofer. He had omitted a piece of chimney flashing. It was crystal clear and could be easily discerned in a digital photo. Everybody who climbed on the roof saw it easily. The roof leaked in the owner's bedroom during the first rain, causing ceiling and carpet damage. The cost of the repairs was easy to isolate. I browbeat the guy for a while and he refused to pay, saying the repairs were too expensive and he could have done them for half. I wrote a letter indicating that we would pursue his bond if a check was not delivered by Friday at 5... and at about 4 a courier brought it. Your sub may respond the same way, because a claim on his bond will put him out of business.
There were architectural drawings for the whole job but, nothing specified except some bar in the foootings for the garage bay in discussion. No signed contract with this old timer. Thus no specs on proper compaction. My word against his. However, I've now had three different concrete subs look at it and two have said that it could have been avoided with a control joint, bar or WWM and blankets after the pour. I'm guessing he could get just as many so called experts on his side of the coin as I could on mine.
Dave
If you can cut the slab all the way through, you may be able to bolt it and lift out as much as a 4x5' section with a skid steer. We have used that technique where the space would not allow the use of larger equipment (faster).
I first saw that method used in a repair of heave concrete aound colums in a Sears store . Sears had signe a waiver releasing the contractor from liability for pouring over frozen ground. They then paid for the repairs when the predicted failures occurred.
Dave