Concrete Footings - What's too wet?

jwhite · Jun 2, 2003

Concrete Footings - What\'s too wet?

I dug the footing trenches for a 36x48 attached garage addition back near the end of April with my TC33D (See attachment). The month of May had 25 of 31 days with rain around here. I had to pump out the trenches with a sump pump every few days as the rain and runoff would fill them up.

I saw somewhere that code says you can't pour concrete into footings with more than two inches of standing water in them. I can sure get the water out, LOTS of practice

. My question is about the wet mud in the bottom of the footings. When you backhoe your footings are supposed to be down to undisturbed soil (no filling).

Do I have to wait for the mud to dry before pouring concrete? Or do I have to dig deeper and get rid of the mud? I am already a couple inches deeper than I need to be. If I go deeper still, can I put some packed gravel in the bottom of the footing or would this count as fill?

Soil here is heavy clay and light shale, so it will be a while drying if I have to wait. I am worried about pouring on top of the mud and having it settle.

As I have never done this before, some advice would be greatly appreciated!

Jay

Anonymous Poster · Jun 2, 2003

Re: Concrete Footings - What\'s too wet?

From a transplanted mountaineer, never pour on mud. Either let it dry out or take out the soft material just before placing the concrete. You have more wet weather headed your way. You might want to wait until the current weather cycle changes. I was near Hinton recently and you (like us here) are having lots of showers this spring. /forums/images/graemlins/confused.gif

Anonymous Poster · Jun 2, 2003

Re: Concrete Footings - What\'s too wet?

Don't pour concrete onto mud!!

What you may want to do is to dig a drainage trench that leads from the footing exacavation to some point downhill so that the water can drain out. If no downhill, dig a big hole for the water to drain into.

Darren · Jun 2, 2003

Re: Concrete Footings - What\'s too wet?

Like everyone said, absolutely do not pour over mud. I've seen a lot of cracked masonry walls where that was done including houses that cost mega bucks.

bellweather · Jun 3, 2003

Re: Concrete Footings - What\'s too wet?

we also built our garage in early June, clay soil and lots of rain. before pouring the footings the builder first put down some crushed stone, though I think there was no standing water in the trenches at the time of the pour... see attached image...hope this helps.

jwhite · Jun 3, 2003

Re: Concrete Footings - What\'s too wet?

I will not pour on mud, just trying to see if I should wait for it to dry, scoop it out and/or add some kind of stone in the bottom.

It sounds like I am going to have to wait for a weather pattern change, wait for a dry out and then shovel out any remaining loose material or soft stuff.

I just it won't hurt to have deeper footings, just more expensive. By my calculations, it adds about 3/4 of a yard of concrete for every additional inch.. I figure about 3 inches more will be needed so far....

2 more inches of rain today, time to crank up the sump pump again :-(

CtRick · Jun 4, 2003

Re: Concrete Footings - What\'s too wet?

You may want to consider installing some curtain drains to help. The last building I put up was in such a wet area that we had to put about 4" of crushed stone under the foundation.