Hi,

We poured a concrete driveway about 1 1/2 years ago, and it's got pits all over the surface (about 1/8", and when you walk on it the concrete just dissolves into sand or comes off in large flakes that are sometimes as large as 2"x3". We noticed a small amount of pitting last summer, but not extensive, and now as winter is winding down, the entire slab (about 1,400 square feet) is all pitted and/or flaking. Can you tell me what would cause this and can we fix it? I have a friend who says he thinks it is a bad batch of concrete, is this possible, and would it be normal to take 1 1/2 years to show up?

Thanks for your input,

Stacey

I'd agree with your friend, sounds like bad concrete. What does the Contractor who poured it have to say about it? Did it come with any warranty?

No warranty that I know of, the guy who installed and finished it is a small one man show, so he probably doesn't have a strong desire to do it over for free. However, I arranged for the concrete myself, with my account at the supplier, so if the concrete is bad, then they should at least pay for new concrete. I emailed the supplier and they are going to come out with their QC guy and take a look, but I'm worried they will try to blame the sub who installed it (finished and brushed?).

Can you tell me is it possible for the installer to cause these problems with his work? Or does he get blamed for not recognizing a bad batch of concrete when it was being poured? I'm not looking to blame him, since I'm the general on this project I think I would hold most of that blame. The concrete looked just fine for a year and then in the second winter is when it started falling apart. What I'm hoping for is just an understanding of what portion of responsibility we should accept as the general contractors, and what could be apportioned to the supplier of the concrete. If the installer has any blame then I will talk to him and see what he is willing to do. I did call him yesterday and he wasn't much help, he mostly sounded like he didn't want to get blamed for this, and I suspect that we will absorb any of the fault that might be his.

I should mention that this sub we hired for the concrete work also did our garage, basement and porch, and we have had no problems with any of this, so I'm leaning more toward a product problem than an installation problem. I just don't know enough about concrete to argue with the supplier if they try to blame the installer. They are a large, reputable company in the area, so hopefully it won't be a problem, but it's easier to have a conversation if I can speak intelligently.

Whew! Sorry this is so long winded! Thanks for your input.

Stacey

I doubt it was anything the installer did. They usually do a QC check on the concrete at the batch plant and may have a report on that batch, perhaps they gave you something? What was the temperature when this was poured? Was there any standing water present while it was being poured? Have you been using salt on it for snow / ice melt? Did the garage, basement and porch all get poured at the same time as the drive or from different batches? I'd be curious to hear what the concrete supplier says.

I will let you know what the supplier says when he calls me back. As for the temp and such, it was the end of May when we poured, and I don't think there was any standing water. We live in a fairly dry climate, and usually the end of May is getting nice. We don't use salt on the driveway or any kind of snow melt - we are lucky because the driveway is very flat so we don't need to do anything when it snows, just drive over it. We did have a friend come with a shovel on his truck and remove some snow, but he didn't make it down to the concrete, there was a good 2" layer of ice. The basement, garage, and porch were all poured at different times. Basement in October of prior year, garage in January 2006, and porch early May 2006. The driveway was poured in 3 batches on two consecutive days at the end of May, 2006. We used 5 1/2 sack and according to the tickets, the first load was 8.5 yards and they added a total of 10 gallons of water to it. THe second load was 7 yds of concrete at a 5 slump. They added 25 gallons of water to the 7 yds. The third load was 4 yds, a slump of 4 and they added 20 gallons of water to this batch. Seems they added a lot more water to the second and third batches, which are the sections of concrete we are having the most trouble with. The first section poured is also showing some pock marks, but not as bad, we think. Some of the driveway is still under ice, so we aren't sure. Thanks for your help with this.

Stacey

OK here it is. Did the installer work alone or with 1-2 guys to help? If he wasn't working with experienced help the concrete could have set to quickly. Were you there to watch the work? Did he have to spray water over the slab to help finish it? If so that could be the issue. The more water you put on the more "cream" you get on the top. This works fine for a while but, it will cause issues down the road becaue as you work the concrete the rock and cement will settle. The sand and water will work to the top. Thus causeing the flaking and pitting. Was the slab poured on sand or dirt? Was the base sprayed with water before it was poured. If the ground was dry when poured it could have cause the concrete to dry to fast. The moisture gets sucked out of the concrete from the bottom and the top causing it to dry to quick. Pictures would help but it is not very often you get a bad batch of concrete. If you had a lot of cracking and spliting mabey. Pitting and flaking is usually installer error. I may be wrong but I have poured around 25,000 yards of concrete in my years and have made this same mistake myself.
Mike

Quote:

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Originally Posted by StaceyH

Hi,

We poured a concrete driveway about 1 1/2 years ago, and it's got pits all over the surface (about 1/8", and when you walk on it the concrete just dissolves into sand or comes off in large flakes that are sometimes as large as 2"x3". We noticed a small amount of pitting last summer, but not extensive, and now as winter is winding down, the entire slab (about 1,400 square feet) is all pitted and/or flaking. Can you tell me what would cause this and can we fix it? I have a friend who says he thinks it is a bad batch of concrete, is this possible, and would it be normal to take 1 1/2 years to show up?

Thanks for your input,

Stacey

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Was the sand and gravel washed?? If not it will fall apart.

Ok, here's some additional information. We put crushed rock (3/4- possibly?) down as the base, and also had rebar installed. I don't know if the rock was watered down before the concrete was poured, and unfortunately, I wasn't here when they poured. I am regretting that in a big way at this moment :(

I have spoken with another installer who also suggested that the installer might have sprayed the concrete down too much, trying to keep it soft enough to finish. I believe he was working with 1 or 2 other guys that day, and I know that he had enough time to trowel cut the edges.

I also spoke with the supplier, and they rarely have batch problems, as most of this is done by computer, but he was going ot check the weight batch tickets, to make sure enough air was added.

He suggested that we might consider hiring a company to take a core sample. He says that we can tell if the scaling is caused by too much water, lack of some critical ingredient, over-finishing, excess exposure to de-icer (not likely as we don't use it.) etc...

My guess at this point is that is an install issue. I'm wondering if the core sample is worth the cost - about $1,200- 1,500, I think. HE did say it was the worst case of scaling he's ever seen on such a new slab.

One last thing, how important is sealing an exterior slab? I've read that it's important, but then been told that it shouldn't scale just because the slab wasn't sealed. We are trying to determine if the slab was sealed or not. There was so much going on at that time that we can't specifically remember if our guy came out and sealed it or not. Just wondering if that is our answer.


Thanks for all your input everyone, it's been very helpful and educational.

Stacey

Hello,
It sounds like you have a good base under your slab which is good. The bad thing is there really is not an easy fix to your problem. There are products you can put over the slab but, at who's cost and sometimes it flakes off as well. The only right way to fix it is to replace it. I know you do not want to hear that but it is true. With out seeing it first hand I hate to say too much however, this really does sound like an installer error. If there was too much water put on it while finishing, you have a problem. If it was finished too much, you have a problem. The fact that the edges have been troweled doesn't say much as it is the easiest part of the job. My 14 year old son has been troweling edges for me for 3 years now in the summer. Here is the facts, too much water or over finishing will cause the same problem. It works the cream and sand to the top of the slab while all the concrete mix and rock settle to the bottom. This is what causes the flaking and the pitting. This does not sound like a bad batch of concrete. I am curious about one thing. You say they poured with a 5 slump and a 4 slump. In order for them to know what slump they were pouring they had to test the concrete right before they poured. 1st ?/ did they have a 5 slump before they added 25 gallons of water or after? 2nd ?/ Most generally if you are required by code to do a slump test you are also required to take a cylinder sample. If a sample was taken the installer should have it and you would not need to have a core drilled to test. Where I live it runs about $125.00 to have a cylinder sample tested. I would check with your local building inspector to find out if cylinder samples are required. I would not front the cost for this. Does your installer have insurance to cover this kind of thing?
I always like to seal my concrete, however, I do not always do so. Sealing the slab will help with repelling water and make it easier to remove oil spots etc.. But, it will not prevent the problem you are having. I find it hard to believe that you had two separate loads delivered and both were bad batches. The 7 yds and the 4 yds were mixed at different times thus meaning the supplier would had to have screwed up twice. If they have had no other issues with any of the other pours they made on this day the problem should be fairly obvious. I hope I have helped a little. Good luck.
Mike

Hi,

Thanks for your insights, I think you are correct about it being more likely faulty installation than bad concrete. There were 3 batches in all, and the first batch is by far the worst, but we are seeing some scaling in the areas where the other two batches were poured. The first batch almost the entire surface of the concrete is scaling; with the other 2 batches, only small areas (2'x4' area) are scaling. My only point with the trowel cut comment was that the concrete hadn't set up too much to do that. On the other 2 batches, that were poured the second day, he had to saw cut. I was thinking that this might indicate that he had more time, but I see that it probably doesn't mean that. The slumps I reported were what the concrete was before pouring, and then the water was added after that, so it would have changed that slump upward depending on how much water was added. As far as I know, we don't have to take a cylinder sample here, but I'm not positive, so I'll check into it. If I ever pour concrete again I will be sure to do that, however. Thanks for your help!

Stacey

Quote:

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Originally Posted by StaceyH

Hi,

We poured a concrete driveway about 1 1/2 years ago, and it's got pits all over the surface (about 1/8", and when you walk on it the concrete just dissolves into sand or comes off in large flakes that are sometimes as large as 2"x3". We noticed a small amount of pitting last summer, but not extensive, and now as winter is winding down, the entire slab (about 1,400 square feet) is all pitted and/or flaking. Can you tell me what would cause this and can we fix it? I have a friend who says he thinks it is a bad batch of concrete, is this possible, and would it be normal to take 1 1/2 years to show up?

Thanks for your input,

Stacey

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Stacey,
I am sorry to hear about your driveway it happens all to often with new construction. There is something that I have used and it works great for refinishing your driveway without the expense of tearing it out and redoing it. The product is called Flexset concrete repair. They use it on airports and it is approved by DOT it is easy to apply and sets in about 1 hour and it looks really good. My father in laws driveway was very pitted and was starting to crack in a couple of places. We used this stuff and recovered the entire driveway and that was 5 years ago and with the extreme temperature changes and stuff here in Utah it still looks great. Well I hope that helps I just wanted to give you an alternative to tearing out your entire driveway to redo it. This will last for years and they say it doesn't shrink or contract and does not matter if it is hot or cold. You can apply it year round as well. Good luck.

G

Hello me again,
I have heard plenty about Flexset... nothing bad other than the price $100.00 for 5 gallon bucket. I know this would be cheap for a home owner who simply has old concrete, but for some one who has paid for new concrete it's a bit much. I would not settle for a cover up on a project that was done incorrectly. I will not put the Flexset product down because it is a good answer to poor concrete. I, as a contractor, would never ask a home owner to accept any cover up product in place of good concrete. Just an opinion. In any other case... use Flexset.
Mike

StaceyH - I think that a lot of water was added, which makes the concrete flow and spread a lot easer and faster BUT it makes the concrete a lot thinner and weaker then when it first got there. Also when the concrete got there was it already what we call ( HOT) concrete , This is when concrete has already been in the truck for to long and the chemical reaction of cureing ( setting up ) has already started , I have had this happen several times and I have refused the load, because it is a bad loasd and will not make a good slab or what eveer you are pouring.. A good exper. Concrete person can tell when they have brought HOT concrete. My guess is kind of , that it is the fault of both of the parties,-- Hot concrete , Too much water added to the concrete, Pour job finnishing, Should have put down plastic before pouring ,this would have kept the water from pouring out the bottom of the slab & causeing it to cure to fast . HOpe I have helped some ,Good luck and GOD BLESS :::F.B.E.

Naw... putting down plastic will force ALL the moisture to the top and cause the same issues. The fact that water was added has nothing to due with the supplier if the installer requested it. It is very rare that a supplier brings HOT concrete... mabey if you are pouring with added cloride... I still think installer was un prepared

I'm not sure where to start. First off too many people simply blame the finisher for all the problems. I have poured concrete for 25 years. Here in Idaho we have been experiencing the same problems the last 2 years. I have not changed how I pour concrete. A decent concrete finisher can easily finish 10 yards of concrete by himself, so if there were 2 or 3 guys, this should not have been an issue. To hear everyone say he put too much water on slab to help finish sounds like they saw him do this. Since no one was there how do you come to that conclusion. Are you having the same problem on the other concrete around the house? Is the spalling happening over the entire driveway or just where the car traffic is heavier. Plastic is not a good idea. If it was poured in May I wouldn't think it was hot enough to have to add surface water. Pouring concrete at a 5 or 6 slump will not cause spalling as long as it is struck off properly. We do not know this so we can't assume the finisher "lost it". We have had a big deal about this here in Idaho on the news and in the papers. I pour the same way every time and sometimes have to add water depending on weather conditions and wind. I have had a couple of jobs spall and they were under varying conditions. Neither were too extensive, luckily. But there are a couple of contractors here with large subdivisions where most of the driveways have come apart and there are lawsuits now. So the contractors and the ready mix company have tested everything. The testing showed that there was Magnesium chloride on the bad slabs. This was found to be what the road dept. was spraying on the roads to help melt the ice. This in turn is picked up by the cars driving through the snow-slush-ice and then driving or parking on the driveways, where it then melts off the car and sits on the driveway. I do not know where you are located, but this might be one reason for your problem. Contact the road dept. and see what they are using. This could be the fault of many different things, but please don't immediately think the installer is always at fault until all the facts are known. Thanks for putting up with the long response.

Hi Mudman,

I'll try to answer your questions, but first, thanks for your well thought out response. You obviously take pride in your work and have good experience. I do know that the finisher put water in my concrete, but don't know for sure if it weakened it. He added 25 gallons to 7 yards of concrete, and then 20 gallons to 4 yards. Our trim carpenter mentioned the quantity of water that was added when the concrete was poured as he was here and saw it happening. Also, the finisher had to saw cut joints on 1/2 of our concrete because it set up too quickly, but on the other half, which was poured on a different day, he was able to trowel cut the joints, so I know there was a problem. The finisher himself told me (when the spalling happened and I called him) that the concrete arrived too early and sat too long, so that he had to add water to loosen it up. I told him that he should have sent it back if it was that bad, as he took away any option I had of arguing with the supplier when he signed the batch ticket agreeing that the slump was 4 if it was in fact something other than 4. When I look at the batch tickets it looks like the mud was in the truck for 45 minutes to an hour before it was poured, and I don't know whether that's because the mud arrived early or the finisher was late.

The finisher thought it was the de-icer stuff too, but for the whole first year we lived here we had dirt roads, so there was no deicer on the 2 miles of road I had to travel between my house and the paved roads. I am guessing that most of the deicer on my car would have dripped off by then, but can't say for sure. Also, according to the county, the area I live in is fairly rural, so even once we had our roads paved out here, we are only sporadically de-iced because our road is not considered a priority. I don't think de-icer played a significant role in our slab spalling. Finally, the spalling was worse where I drove, because that area would have much more stress on it, but it was also bad in areas where no cars or other machines ever drive, like under our basketball hoop. It was also bad in front of my husband's old beat up truck, which he never drives, it's just for hauling junk and hunting, so it's rarely if ever in snow, picking up de-icer. Just so you know, we finally just tore out all the concrete and paid for it ourselves, and then hired an asphalt company to come lay asphalt. We decided that it has lower risk as you can cut sections out if you need to, and repair things more easily. Our finisher never accepted any blame, but did agree that he would re-pour our concrete at no cost to us, but we would have to pay for the material. He also GUARANTEED us that it would spall again. In the end, we decided he wasn't worth the risk. My advice to anyone considering paving a driveway, is to let the contractor arrange for the concrete him or her self, so that if there is a problem, you don't have to play monkey in the middle with the supplier and finisher.

Quote:

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Originally Posted by ;

concrete arrived too early and sat too long, so that he had to add water to loosen it up. I told him that he should have sent it back if it was that bad, as he took

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I'm sure mudman will agree here. When a load arrives and you ordered a 5 or 6 slump and it cames out the chute at about 3 to 4 then you start to worry. You ask the driver to see the slip and what slump was on it, then you ask him about the load. You put your hand on it and its HOT. That's were the word Hot Load came from. In hot summers timing is SO important, When we have larger pours and our timing is a bit off between trucks , I get the driver to find some shade if he can and park his load there for a bit.
I feel that between the load coming out and sitting or sitting and it was part of a hot load coupled with the finisher not being ready helped to start the problem. Here's how that domino's. When you are pouring a load that's trying to go hot on you, as you pour you tell him to shake it up. Spinning the barrel does help. If that's not enough then shoot some water in it. Crete reaches a point that Minutes count. As time goes on it starts to get ugly real quick . This is why us Crete finishers cuss at times. You started with x men to place and now semi hot load that's by the MINUTE is going all hot and now short by 3 men etc.
Once it reaches a certain point that's it. Don't pour what you are going to tear out later.
Concrete is never the Same twice so to speak. Sun Temp Wind heat time of truck to job etc effects placing crete. The simple magic to concrete is get in in fresh and QUICK. The other trick is timing the loads so not to get what we call inn the cret trades a cold joint.

Plastic on the stone bed helps so does hosing it down real good. When crete is taking off there no stopping it. Its Always the boss.

I think is was a combo here. Driver a bit early. Finisher not ready, Hot day, Now not enough experienced help. Load shot with too much water. Placed concrete sprayed with water again. That about kills the crete. Ask Mudman he knows exactly what I'm talking about.

The basic problem is an less experienced finisher needs MORE men to place and finish Just screeding and wet benching can be a make or brake on placing.
Well That's My 30 years of pushing mud oohh1 I'm over 50 and still can out place the new less experienced guys and that sounds like what this is mostly about. Crete plants nowadays are real Sharp and it tech crete now. The state pours is what helped quality control.

Note here: If the finisher wasn't ready for the time slot and a 1/2 hr went by he basically going to eat the load. 1/2 hr is the window every crete finisher tries to achieve to unload the truck The max is 1 hr on a colder day. When its to cold 50 you wish you had a hot load or put in 2% accelerator and not just hot water.

Signed 21 Boat

If I Helped To Answer Your Question Please Rate My Answer

Well I did not know that the mud sat on the job and had to wait for such a long time. He certainly was not ready. I actually saw cut all my jobs, so as to pour more at a time to try and stay away from multiple pours in the same slab. Too much movement between pieces and straighter control joints. The de-icer thing though still might have helped the problem. The ice and snow will stay under the car for a while if its cold.( we call them ice boogers here in Idaho) then when it warms they melt and fall off where car is parked. But after hearing the whole story I can see that the creter had problems and I came off sounding kind of lame. Sorry, but not all concrete guys are bad and sometimes we all get bunched in with the bad. I'm 45 have been doing it for 25 years, have all insurances and licenses, and all our work is word of mouth. So I let my work do the talking. Has worked out so far. Sorry you had a bad experience with a creter, but rest assured there are still good ones out here and if you ever have another question or job just post it and we will try to help. By the way Stacey where are you located/

Hi 1 mudman. You didn't sound lame at all. Any any all information is good when it just plain good information. It can actually trigger another thought or approach for everyone trying to help out and spurn more approaches and ideas.

Welcome aboard!

Signed 21 Boat

If I Helped To Answer Your Question Please Rate My Answer

Hi Mudman and 21boat,

Thanks for all your input, and Mudman, I didn't think you sounded lame either. I believe you that there are good finishers out there, and wouldn't hesitate to pour concrete again, I would just make sure I had a good finisher. I think that was my main problem. I like to hear that there are people in the world who take pride in their work, it affirms my belief in the goodness of people.

Stacey