Hello – this is my first post to this forum, hopefully you all can give me some direction.
First a little background: I am a homeowner doing a large remodel. We puchased a house we thought we were going to do some commetic work on and instead found a myriad of structural issues and had to change gears on the project pretty signifigantly. This meant pouring a new foundation for an addition that will house the new kitchen.
Here’s my problem:
When we poured the footing for the addition, I ordered a 4000psi exterior mix. I think it ended up being about 4.5 yards. Because of the nature of where it is on the property we pumped the concrete into the forms. When we poured the mix was obviously very wet, but the pump operator said he needed it that way for pumping. The company told me they required a 5 slump but I bet this stuff was closer to 7 or 8. We have two bar runs through the wings of the footer and verticals every 24 inches in #4 bar.
As it cured I observed some pretty signifigant shrinking of the concrete, but the surface seemed pretty good and we decided to move forward with the stem wall forms. We left the footing forms in to help keep the dirt away from the footing so we can tar them later. We just poured the stem walls and now that I’m taking off the footing forms I’m finding that the footing seems very weak. Its gouging heavily with regular tools as I pull for the forms and I’m honestly very suspicious that the footing is not up to the 3500psi that was speced in the engineering plans.
The redi mix company is going to come and do a tesrt this week on the footing to see where it ended up strenght wise, and if it fails, I’m in a real pickle. We’re basically about $8k into this foundation build, and ripping it all out and redoing is something I cannot even fathom.
Has this every happened to you guys? I’m not sure what to do.
Thanks.
Replies
How long ago was the concrete poured? It takes a couple of weeks for concrete to develop most of its strength.
It was poured roughly 3 weeks ago.
Did anyone on the jobsite request water to be added to the redi-mix at the time of the footing placement?
Not that I know of. I ordered it at a 5, which the pumping company said was ideal. Looks like the redimix operator took matters into hhis own hands and watered it down further, however I did not see the initial mix beofre it was watered. He just dumped it in and at that point it was too late. I suppose I could have rejected the mix when I saw the clean mix out of the hose pump, but at that point we already had a full yard in the forms.
It dired out a bit as we went on but even the parts of the pour where we had (what seemed to be) a decent mix it has cured in such a way where you can see obvious signs of excess water in the cured footing.
That is BS. I have had 4 slump pumped a number of times and 5 is no sweat.. They just shoot a bucket of water in the hose to start and again at the end.
The first little squirt is soupy, then you start getting good mud.
In real life, for a footer, you are probably going to be OK but they didn't do you any favors.
This is what I'm hearing from a buddy who does industrial concrete public works projects. I think the pump company would have been fine with a dryer mix, and that the fault really lie with the Redi Mix operator over watering.
I did the stem wall in 8 inch core ICF filled with 5000psi, anticipating another wet mix, and it has begun to cure very well. The slop from the pour that was on the ground is incredibly hard, so hopefully that will aid in any long term strengh issue with the footer.
We're framing in wood, so there will not be a ton of load on the footer, but even so I will be backfilling with squegee and topping with clean fill from the job site to lock it in place. Hopefully this will aid over time in keeping it stable.
One question: Is it nessessary to tar the outer edged of the footer? we placed it 3 inches lower than frost line for good measure as well.