Backhoe How to use backhoe; or being lazy.

[CurlyDave]

I'm not sure a building inspector will be agreeable with this method. it's supposed to be undisturbed earth under footings in our area.

Of course, you are right, undisturbed earth, or at least well compacted earth is best. OTOH, as a practical matter, every residential footing I have ever seen had quite a bit of debris in it by the time it was ready to pour concrete. Usually, putting the steel in knocks a lot of dirt off the walls of the trench, and scooping it out is impractical since the steel is now in the trench.

All the contractors I have ever watched just wet it down a little bit with a hose and pour right over the debris. I have always wet it down enough to make mud a day or two before, depending on the weather, and then poured over dried mud, after a short spray right before pouring, to keep the concrete hydrated. The inspector might not like it, but it is better than the usual job.

 

[raykos]

Hi all,

Thanks for taking the time to respond, appreciate it.

Reg:

are you digging it wide with a skinny bucket ?

Yes, that's what I'm doing, and as you and others pointed out, it's just a trench and after it's covered who will see it? I probably should have also mentioned that this trench is curved and I'm going to be using 4" corrugated flexible pipe. From past experiences I've found this type of pipe(vs. rigid pipe) is less trouble to install and will lay nice and flat if the trench is relatively clear of debris.

So, as another member pointed out, if I can learn to keep the teeth horizontal while drawing backwards, I may be able to get rid of most of the debris and won't have to dig wider in order to use a shovel. Plus, as 'CurlyDave' pointed out, I can wet it down and let it dry if necessary.

 

[AndyMA]

As one of the "old guys" on the list I thought I'd chime in. I've been running backhoes/excavators for years and currently have a Woods 11 foot hoe with 12 and 24" buckets and a 44,000 lb Hitachi excavator with a 36 inch (very narrow bucket).

The 8" bucket you are using is extremely narrow and hard to work with. I suspect material does not fall out of it easily. I have never removed teeth from a bucket (except when they broke off) for digging a trench. I have used trenching buckets that have no teeth, but a hardened flat edge. I find usually I can do just as good a job by keeping the bucket with teeth level with the trench bottom as I curl it in. It is a skill that takes a while to master. I stll remember bounching tractors all over the place while trying to learn to use a backhoe. Many times trenches and virtually all electrical trenches have a layer of sand (could be one foot deep) added before putting the pipe or wire in to eliminate stresses. Also sand on top of pipe or wire. This is required by code in many areas.
BTW you can smooth the bottom of a trench with the bucket flat being pushed away from you (and pulled in) or with the fingers (teeth) on the bucket being dragged forwards and backwards like a comb while being oriented 90 degrees to the bottom of the trench. Hope some of this helps.

Andy

 

[AlanB]

On the foundations I have seen them do here, several of the contractors have a slip over shoe of something along the lines of 1/4" plate. They slip it on over the teeth, and it wedges in place, and if they need to dig through something tough and need the teeth, they hook it on an edge of something (trailer or wall or whatever is handy) and pull it off, or knock it off with a sledge.

I was intriqued last time I saw it, and asked the site foreman, he said that little widget saved him one man on the job from cleaning the bottom of the trenches.

I have not built one for mine, my small bucket is flat faced w/o teeth already.

 

[dfkrug]

Lots of good tips here.

My $.02:

If you dig a 12" trench, use a 12" bkt. A bkt narrower than your trench
will make it hard to clean the bottom efficiently. I tried a 8-9" bkt before
and find it too narrow for trenches, at least the kind of trenches you
need to stand in.

Bolt-on bkt teeth are removable, but I find that the threads get mashed
and the nuts get corroded, so it is not somethng you would do casually.
Dirt gets impacted around the nuts, too, so it takes a bit of work.

 

[AndyMA]

Lots of good tips here.

My $.02:

If you dig a 12" trench, use a 12" bkt. A bkt narrower than your trench
will make it hard to clean the bottom efficiently. I tried a 8-9" bkt before
and find it too narrow for trenches, at least the kind of trenches you
need to stand in.

.

Personally I think a 8 or 9 " bucket is only good as an excercise tool to see how many times you need to jump off the tractor to clean it out. Sticks, rocks and even hard soil wedge in it and need to be forcefully removed. I would say a 12" bucket is the smallest useful size unless you have very controlled digging conditions. I've used "clip on attachments" to turn a backhow/excavator bucket into a blade and they can be made to work well if you know how to keep you backhoe bucket parallel and at the same depth as you curl it in. I still believe if yo can do that well, either using the teeth facing forward in normal mode, the bottom of the bucket or the teeth facing straight down like a comb as I described earlier will work just fine. Taking off the teeth is just too much work for such little benefit (and by the way mine are welded and or peaned on depending on whether I have broken them off or not)

Andy