demo house bid; it has 12 inch thick poured concrete walls 8 feet high and concrete floor

[lake side bob]

Thinking of submitting a bid to tear down a house, two story, with poured concrete basement walls that are 12 inch thick and the thick footing for a 12 inch wall; the walls are 8 feet high.
I have a CAT 312 hoe with long stick and 42 inch bucket, thumb and a frost/ripper tooth.
Looking for comments on the use of the 312 to demo the concrete walls.
12 inch thick plus the footing I am thinking may be to much for the 312 excavator but am asking for your thoughts, do not want to damage the 312.
Also any comment on how you would break up the walls???
Any comments would be greatly appreciated.
This Heavy Equipment forum is a great site.

 

[catman13]

I'm thinking a 320 or 330 with a hammer on it , because it is probably full of rebar.
I would bid it with your 312 and big rental machine ,and use the 312 for moving busted concrete so you don't have to switch the big machine from hammer to bucket.
bid high and if they take it fine , or let some one come in low and bust their stuff up , if you don't get it watch how it is done so you can bid on more jobs and know what type of machine you will need next time.

 

[CM1995]

Catman13 pretty much hit it the nail on the head. You're 312 will not handle those walls.

I don't know the rental rates in MN but a 320 with hammer in my area rents for around $6500 a week. Of course I haven't seen the house to be demo'd but from what you describe a week of rental should suffice to hammer the walls, slab and footings out once the wood framing above has been removed.

1000 SF of residential demo is around 100 CY of debris, this is the formula I use and it comes out close every time I've done one. If the house has personal contents then the formula needs to be adjusted up depending on how much crap is in each room.

Price it to make money - my Father always told me he never lost money on a job he didn't get.

 

[td25c]

We have a make shift wrecking ball arrangement on a 12' choker cable for the excavator .

Use it to bust & fracture the walls . Then on footings & flat work we pick it up with the thumb & just drop it .

 

[AzIron]

The size of the rebar is what will make the walls easy or a bear banging on concrete with rebar is slow going a big hammer simplifies life or a wrecking ball and good hands

Cm that's a steep price to pay for that size of machine and hammer I am kinda shocked by that price I am paying under 5000 a week after taxes for that combo

 

[Welder Dave]

I think you need a bigger machine with a breaker or a wrecking ball. The footings could be massive. My former neighbor does demolition but when he 1st got into it used a 3/4 yd. machine (32,000lb) with a 3000lb. wrecking ball and took out a bank vault. It was all the machine could handle swinging the stick in and out and it took a lot blows but eventually pulverised the concrete. I think a wrecking ball works good on massive concrete that isn't selective because it creates shock waves that break it down. A hammer works too but is better for controlled breaking. You might have to have a water supply or hook up to a fire hydrant to keep the dust down.

 

[catman13]

how far away is the next house?
with a ball you got watch for flying pieces and the windows.

 

[Tinkerer]

Bob, there may be some relevant info in this thread. ---->https://www.heavyequipmentforums.com/threads/where-are-the-wrecking-balls.34894/

 

[suladas]

The biggest question is, how long are the walls and what shape are they in? If they are somewhat in disrepair and/or have no rebar the 312 will pull them in no problem provided you can reach across to pull them in, if you couldn't, you could pile dirt so you can drive over wall to get at it. Most houses are 8" walls here and the 210 pulls them in without even knowing they are there most of the time, the odd 12" wall is no different, but most of the time there is little to no rebar in them.

While it was not fun, I did one house demo with my 6 ton mini ex, no hammer pulled out foundation with very little issues. Once you have a section in the center pulled in, they go in quite easy (provided it's not winter and they are frozen). Once you got sections loose, simply dropping them on the floor will break them up into workable pieces.