Preparing rocky, hard-packed fill before loaming

[Dougster]

Yet again, I turn to my highly experienced friends on TBN for a little advice. Up until now, spreading and raking out prescreened loam has been pretty straightforward and uneventful. I'm typically dealing with relatively small areas, often with a little re-grading and/or stump removal to do first. Occasionally, a large rock or two has to be pulled out. Other than that, very little has needed to be done before the loam trucks arrive and I go to work.

But what do you do when you are dealing with a fairly large area of low-quality, hard-packed fill that has set up like concrete? This stuff is 1/3 clay, 1/3 mixed gravel and 1/3 various sized rocks & debris. I don't even know if I can bite very far into it except with the backhoe... and I'm afraid it will ruin my boxblade if I go that route first. It's that nasty! I'd be tempted to back-drag the worst areas with a heavy-duty toothed bucket first (before attacking with the boxblade), but I don't have one yet and now it looks like I might not have one for some time to come.

Should I just ignore this concrete-like fill, remove the worst offending surface stones... and simply spread the loam as usual? Or would you prepare the existing surface first... either by bringing in sand or something else to layer between the hard-packed fill and loam... or maybe by some sort of mechanical preparation of the hard-packed fill? Or both? I do not mind going with rental equipment if that's ultimately going to provide the best solution and save my own equipment from yet another nasty, unnecessary beating.

Dougster

 

[EdC]

Dougster

By no means do I have that much experience but I sure have been learning about clay and rocks this past year.

I bought a Rankin 3 pt. ripper for a bit over $200.00 including sales tax and it works great for tearing up red clay mixed with the lava and basalt that are common on my patch of real estate. A few trips with that and you should be able to use the FEL with no problem. I have used mine to rip out part of a driveway that was not done well and also ripped through dirt, clay, and lava to run my irrigation lines.

 

[3RRL]

I can't address the last paragraph of your post, but I would not hesitate to attack and area like that with a heavy boxblade.
You don't need all the scarifiers in the boxblade down. You could lower 1, 2 or 3 only and hang lots of weight on the box for better penetration. You also don't need to have them way down low either. Just enough to cut and rip what you want. Then use the boxblade for moving and smoothing what you've ripped out.

 

[Dougster]

I can't address the last paragraph of your post, but I would not hesitate to attack and area like that with a heavy boxblade. You don't need all the scarifiers in the boxblade down. You could lower 1, 2 or 3 only and hang lots of weight on the box for better penetration. You also don't need to have them way down low either. Just enough to cut and rip what you want. Then use the boxblade for moving and smoothing what you've ripped out.

That was pretty much the original plan... until I saw just how this nasty stuff had set up. It's about the most brutal conditions I've had to attack on such a large scale and where using the backhoe would not be fast enough to be practical. Let's just say that this "fill" did not exactly come from virgin sources.

Dougster

 

[Dougster]

Dougster By no means do I have that much experience but I sure have been learning about clay and rocks this past year. I bought a Rankin 3 pt. ripper for a bit over $200.00 including sales tax and it works great for tearing up red clay mixed with the lava and basalt that are common on my patch of real estate. A few trips with that and you should be able to use the FEL with no problem. I have used mine to rip out part of a driveway that was not done well and also ripped through dirt, clay, and lava to run my irrigation lines.

Hi Ed - That's not a bad idea at all. Affordable too. If I were to loosen it up with a ripper first, I'd feel a lot better about then attacking it with my boxblade. Part of the problem is that my boxblade is a TSC "Farm Force"... not exactly what anyone would ever call a premium brand. It's times like this that I wish I could have afforded a Woods or Land Pride.

Dougster

 

[MarkV]

How much loam is the fill going to be topped with? It would seem to me if you are talking 6” plus of loam then by setting the boxblade high to knock down the highest spots of the fill down would be enough. You start turning up the fill you may find yourself with a lot of debris clean up.

 

[Dougster]

How much loam is the fill going to be topped with? It would seem to me if you are talking 6 plus of loam then by setting the boxblade high to knock down the highest spots of the fill down would be enough. You start turning up the fill you may find yourself with a lot of debris clean up.

The client is talking an average of 3" of loam... nicely spread out and raked... and then hydro-seeding. While considered fairly substantial in this day and age, I don't think 3" of loam is not going to be deep enough to just ignore the seriously nasty "concrete-like" condition of the fill. But you are correct: preparing the fill beforehand is going to expose a lot of debris & rocks and take a lot of extra time... something the client may not wish or be in a position to pay for.

It's always important to remember that I am competing financially against bobcat services that will spread this loam at the speed of light for a song. May not be pretty or give a great finished lawn result, but they'll get the work and I won't because the only way I'll do it is to do it right.

Dougster

 

[hemiguy]

Dougster,
You definitely have your work cut out for you. Rock filled clay is absolutely the worst thing to use for fill. Clay (at least the stuff we have here in the northeast) even by itself does not spread or compact well at all. My experience is that it just wants to stay in big hard chunks (dry) or get very slippery and sticky if wet. An 8 ton dozer would certainly be more effective than a 2-3 ton compact tractor. A 4-5 ton skid steer might be slightly better, but even then its going to be hard to get a nice finish grade with only 3" of top dress.

I was just lucky enough to find 100 cu yards of sandy fill to do a pool fill in for only $400. However, the customer's existing lawn is actually made of what you describe plus some chunks of concrete and blacktop too. It has obviously never had any topsoil put over it. There were two planting beds that I needed to dig out and they were even made of the same stuff! Previous owner was a contractor that build the house for himself and used construction fill to grade the whole yard.

Anyway I first tried using the loader to just scrap the planting beds off and it was futile. I finally had to use the backhoe to loosen up the stuff first. But the sandy fill dirt spread and compacted nicely later in the pool hole using the box blade and back-dragging with the loader. Some clay, rocks, and other stuff went in the bottom of the hole (4 feet deep) first though. I do still have to go back and topdress and seed.

If it isn't too late for you to pass up this one all I can say is good luck.

 

[Egon]

Off hand I'd say a Cat 14 grader with rippers would be the machine for the job.

Back to reality:
Level as best as possible without banging up equipment you already have, spread the loam and be done with it. Explain beforehand your procedure and why to the owner. Then let him make a choice.

Busted gear is expensive.

 

[Dougster]

If it isn't too late for you to pass up this one all I can say is good luck.

This is an older thread... and, for better or worse, I lost this job to the several week period of recovery I had to take after a serious foot injury (non work-related). The job I am currently working is in a generally sandy soil area... but one filled with large rocks and outright boulders! I am grateful for the softer soil... but these endless rocks are going to be the death of me! Give me stumps over rocks anytime!

Level as best as possible without banging up equipment you already have, spread the loam and be done with it. Explain beforehand your procedure and why to the owner. Then let him make a choice. Busted gear is expensive.

Amen Brother Egon. The plain fact is that my equipment is taking a much worse beating in this funny little tractor & backhoe services business than I ever expected. Makes me keep thinking there are better alternatives out there (in terms of equipment choices) for each and every job... but I can't own them all, rentals are very expensive... and I am currently limited on net towing capability to about 7,300 lbs. I keep looking for better answers, but those better answers are not obvious or fast in coming.

Dougster