Dealing with roots in post holes

[s219]

I'm putting in stairs down a 25 foot bank, approx 35 degree slope. For landings, I'm sinking 8 foot long 7" round posts about 4 feet deep, and dry setting with concrete mix. It's enough of a chore as is, due to the slope, but today I was nearly brought to my knees by one hole with roots in it that defied all efforts at extraction. I have this 2" thick root cut off at both ends, but something is still firmly holding it down in the ground. Perhaps another root piece that goes straight down. Anybody have tricks to deal with this sort of situation?? I'd just make this a shallow hole if it was a fence, but for a stair landing I feel like we need the full 4 foot depth. The root is down about 36", so access is limited.

I was able to get my brush grubber around the root and attach a chain, and might try pulling on it tomorrow with my tractor -- will take a lot of rope and rigging to keep the tractor far from the bank. But I am not optimistic. I bet the tractor loses traction before that SOB root gives....

 

[crash325]

Not to be critical, but dry concrete mix is not much better than good old clay dirt.
You can use a fairly dry mix if water is a problem. But I would like mine a little on the runny side.
Sounds like you poles are heavy enough to push the root on down into the hole.

Don't forget to take & post pictures.

 

[RoMad]

It might be a problem if you are near the bottom but I have found that my 18 volt sawzall with a pruning blade does wonders for roots. You can just jab it right down in the dirt and it will cut away without hurting anything.

 

[s219]

Not to be critical, but dry concrete mix is not much better than good old clay dirt.
You can use a fairly dry mix if water is a problem. But I would like mine a little on the runny side.
Sounds like you poles are heavy enough to push the root on down into the hole.

Don't forget to take & post pictures.

I don't know, I have had great luck with dry setting posts. I dry set similar sized gate posts a year ago, and they started out very strong and haven't budged a bit. Still extremely stiff in the ground. One of our subcontractors tore the trim the bumper on his pickup truck when he grazed one and the post didn't loosen at all. Over time that stuff sets up very solid.

In this case, it's hard enough to hustle 50# or 80# sacks of concrete down a hill (need four 50# sacks per post), and I couldn't imagine mixing the concrete on the hill (35 degree slope with no flat spots) or even transporting it down from the top pre-mixed in buckets and then having to prop and hold the posts into position while it sets. I had to keep it simple to make things practical -- need all the help I can get with this job. With the dry set method, I level and fill the post at the same time, and it's solid from there on in, which lets me attach a cross beam right away. I make sure to pack the mix into the hole with a pipe, and give it a few taps with a hammer at the end to help it settle.

The other consideration is that the posts are going into very sandy soil, and at the end of the day, I think the weak link is the soil itself, no matter how you set the post.

 

[s219]

It might be a problem if you are near the bottom but I have found that my 18 volt sawzall with a pruning blade does wonders for roots. You can just jab it right down in the dirt and it will cut away without hurting anything.

In this case, since the roots are so deep, I ended up bolting an old pole saw blade to a stick and then using that to saw off both ends of the root. But something hidden is still holding it down. I have had good luck with a sawzall in the past, but am worried about the depth of the hole and the sandy soil -- I could easily see it getting into the vents of the saw and trashing it. This stuff is almost like packed beach sand, with just enough clay and moisture in it to keep it formed. But it brushes off the sides of the holes real easy.

 

[Bison]

instead of fighting that root it ain't gonna hurt putting that post in that 3' hole.

 

[turnkey4099]

instead of fighting that root it ain't gonna hurt putting that post in that 3' hole.

Agree. 4' hole look like overkill to me even in sandy soil.

Harry K

 

[radioman]

no tricks -- just plain ole sweat and cuss work. When I was digging hole and auger got stuck in one hole because of a flat rock . I had to dig on one side of auger to give it wiggle room to rock the auger by hand and turn it backwards to loosen the grip so I could pry out the darned rock. Looks like you are in same boat and need to dig down by hand and try to wiggle auger and turn it backwards with a money wrench with a cheater bar on it to loosen the grip so you can use a pole saw or something to cut the root. Won't be easy ,but time will get it out with sweat and elbow grease.

 

[EddieWalker]

Murphy has a law that roots seem to enjoy following. I've never dealt with a hole that deep, but I have had quite a few roots that went right down the center of the hole I was digging. It just takes a lot of sweat and suffering to get it all out of there.

As for dry concrete in a hole versus mixing it, I don't feel there is a significant advantage to mixing it first. The goal of the concrete is to lock the post into position and hold it there by friction against the wall of the hole. Compressive strength isn't that big a deal for this type of application like it is in a slab or load bearing pad. If the post was for a sign, or something tall where leverage becomes a factor, then the concrete also acts as an anchor, but then the amount of concrete becomes the biggest concern. Of course, with larger quantities, mixing it is also going to give you a better result.

I've removed and replaced quite a few posts for fences and decks. In every case, the concrete did it's job. They always rot away because of water sitting at the base of the post. Having the concrete come up out of the hole and making it slope away from the post is the best way to make sure the post lasts. Every one of those posts that where rotten at the base of the ground, looked perfect in the ground once I got them out.

Eddie

 

[SSdoxie]

At 3' down and below frost line, I wouldn't mess the root. Pour in about 6" depth of dry concrete and set post on top of it. If you were able to pull that tap root out it might loosen soil deeper than the 4' desired depth and have to be dug down to solid soil.