anybody know about pouring concrete with high groundwater table?

[patandchickens]

(No offense, but I'm hoping for Actual Experiences or contractor-type knowledge, not 'it says on the bag' or 'it seems to me', which I can supply myself <g>)

Does anyone know how bad it would be to try to pour concrete footings for posts (this is for a shed-roofed chicken run), in sonotube, when the water table is high enough that the holes flood fairly quickly if not bailed frequently? If it *would* be a significant problem, then does anyone know a LEGITIMATE workaround (I can think of a couple possibilities but have no idea whether they'd produce a strong enough result)?

I really really really ought to use sonotube and concrete footings for these particular poles, as they're in an area that floods periodically and the ditch runs near our well and I would very much rather not bury p/t wood there (plus this will be, basically, a roofed shed and I don't want the posts rotting out in ten years)

Thanks,

Pat

 

[miss_thenorth]

I asked my hubby--, sorry--he doesn't know

 

[k0xxx]

Sorry, I'm not a contractor and I have no expertise in concrete. However, I was raised in south (very south) Louisiana, and if you dug down more than a foot or so the hole would start seeping water.

In 1974, my father built a shed and poured concrete footings. He didn't have sonotube, but what he did was mix the concrete as my brother and I were digging the hole, then he put a sheet of plastic and folded the sheet so that it conformed to the hole, but all of the sides were above ground. Then he stood the treated 6x6 in the hole and poured the concrete in. We made sure the post was level, and then repeated the process for the next footing.

*(added after some of the cobwebs from my memory were brushed away)
I forgot to mention that he put a layer of gravel in the bottom of the hole.)

I don't know if it was the correct method, but the shed is still standing and it went through Hurricane Katrina (and quite a few others over the years). Part of the shed roof blew off and the shed was in 5 ft. of standing water for a week, but cleaned up and a new roof, it is back in use.

I know you wanted someone who could say with certainty, but I thought that I would pass this along.

 

[patandchickens]

I know you wanted someone who could say with certainty, but I thought that I would pass this along.

Actually, that is a fairly certain (and useful) answer

I wonder if I could do a version of what you describe... tape some heavy-duty plastic to the bottom of the sonotube to make sort of an attached bag-end, then put the concrete in, so that (theoretically, if it all stays together) the water never gets to the concrete.

Thanks very much, you've definitely given me a reasonable lead ,

Pat

 

[enjoy the ride]

From the depth of my "well-this-might-work" building skills- I did put concrete footings in and put piers on top of them and my water table was at ground level when I did it. It was for a hay shed that holds about 6 tons of hay each year and it still hasn't shifted.
I simply dug out the hole, which was immediately filled with water - poured in the quick crete into the hole, didn't mix it at all. Just filled it til it was humped a little above level. Plopped the pier on it. Set just fine and it is in a place where water runs over it every winter. Been 6 years.

Aren't I highly technical? m Of course my soil is really really dense clay.

 

[user251]

I was not a masonry contractor but i did stay at a holiday inn express last night Just kidding i am a plumber and have poured tons of concrete to put in basement pumps. Put in the tubes and pour your concrete fairly dry and it will displace the water and set up fine. I have poured concrete into water several times without any problems. some people even put it in dry and allow the ground water to wet and set it but i don't think it does as well as i think it leaves spots that dont cure at the same speed and makes it have weak spots. Good luck

 

[roosmom]

I am not a contractor. Nor have I ever worked at a concrete plant. BUT, knowledge sometimes is acquired in other ways. For whatever you think it is worth.....Here is some facts..
Concrete needs to cure slowly
The slower it cures the stronger it is
Concrete cures slowest in water
that is why a lot of dams and piers are of poured concrete

If you are mixing it yourself and want to know the mix, then I will find out for you. If you are having it poured thru (sorry dacjohns lol) through a concrete company, then I would ask them WHAT BAG to use, because they (most of them)go by 3bag or 4bag or 5bag or 5 and a half bag.You will also want to know what kind of gravel you want. You get the drift I am sure. Let me know if I can be of more assistance.
Ditto what firem3 said, lol.

 

[akhomesteader]

Concrete poured in water has a higher strength than concrete poured in the open air. I worked as a carpenter for many years one of the tricks we used was to keep test cylinders submerged in a tank of water. They always had a higher crack test than those that weren't submerged.

 

[opiemaster]

As stated above, I have done concrete work in the past, concrete forces out water and will set up underweater stronger, I built a bridge back in '84 itn still stands today, when it floods in the spring, the water gets roaring 10 -15 feet ABOVE the bridge, huge trees have loged on it and everything and it still stands sound and strong. I would mix the concrete, pour it in and go. It wont hurt anything.

 

[patandchickens]

Yeap, well, I did all this last November, so hopefully y'all are right, especially when the water in question was hovering around the freezing point

I have two more sonotube piers to pour for the other run, but it is so mindbendingly wet out there right now (by 'right now' I mean 'continually since last fall, and only getting worse') that there is no way I could even dig a 3-4' hole, let alone try to do concrete work in it I am guessing maybe July or August. Unless of course it's a wet spring and summer, in which case I'll probably have floated out to sea by then.


Pat