Resetting fence posts in very wet conditions

Question

This winter the Minnesota frost heaved up 5 fence posts in my yard.

I've pulled out the 5 posts, and have found basically puddles of water and very very wet mud. I shop-vac'd out the standing water, and have let the holes air out on nice days. When it has rained I've tarped a 8x10ft area to try and get the water down hill. This is what I have been doing for the past week.

Some of the holes are still filled with 3-4inches of water, others are very wet but not filled. The holes right now are around 2ft deep, and I need to dig them to 4.5ft or so.

Should I just dig the holes with standing water? Some of the holes are so wet I'm afraid a deeper hole would just collapse. Or how can I dry them out?

Answer 1

Are you in the Twin Cities? We have lots of clay here. Clay never really dries out ;)

Looking at the concrete, notice how it's flared at the top, this is a nice 'handle' for the frost to grab on to and push up. Ideally, your flare would be the complete opposite...wide at the base of the hole, narrow at the top.

If it's really heavy clay, you may want to forgo concrete completely and instead use compacted crushed rock.

If you stick with concrete, be sure to dig deeper than you need to and put gravel at the bottom of the hole for drainage before putting in the post and concerete. Also be sure to get at least a good 2' of the post into the ground.

Answer 2

I would just dig it out while it is wet. If you really want a clean hole, you could rent a 2 man post hole digger.

That way you can stand far enough away from the hole to keep from caving it in. Personally, I think if you are going that deep, then it does not matter how clean the hole is, just leave some room for grass to grow over the concrete.

The new concrete will still set up with water in the hole.

Answer 3

Above Chicago county 5 feet deep below is 3ft '6'' in. (Twin cities included)
1/2 the post must b in -ground 6 foot posts -need 3 ft underground Make Bell shaped holes , gravel 3 in then cement

Answer 4

I live in a trailor park and they forbid concrete in the ground. Hmmmm…what to do….. I didn't like those metal stake 4 x 4 holders…too weak…So I got creative and bought sections of 8 inch PVC pipe, had themcut to 30", bought cap for one end…glued on the cap…dug the fence post hole, bought Henry's roofing tar to coat the 4 x 4 pressure threated posts (actually 3.5 x 3.5)..up 3 feet from bottom. Let this cure for a coule of days…then I tossed in some sand in the bottom of the fence post holes, just enough to cushion the capped end, put in the PVC 30" section cap end down, then I tossed a bit of sand in the pvc, put the fence post in, tarred end down…so that at leat a 3 inches of pvc were above grade. Then I leveled the post with a fence post level, filled in sand of fine gravel around it to an inch below the lip it to hold it in place and tarred the top shut…it will take a few days to cure the tar. The PVC pipe and cap were inexpensive…you don't need top grade…glue inexpensive and compared to the cost of a sac and a half of concrete…pretty much the same cost and no moisture wicking/leaking fronm concrete into post below grade…the idea is to keep it dry….minimal moisture if any…and not use concrete since I couldn't due to the trailor park rules. One gallon of Heenrys roofing tar did 6 posts and sealed six pvc 8" sections.