Hi,

I need to demolish an elevated concrete slab deck. It's 8 by 16 and
weighs about 4 tons.

My currrent thinking is to use scaffolding to support the slab while I
carve it up using a concrete saw.

Do you have better ideas?

Thanks.

Jack

How thick is it? Seems like between 6" and 1 foot.
You *could* use a concrete saw, but it is real messy: w/o water, you got
dust *everywhere*; second person could hold a vacuum, tho.
With water, it's just, well, messy, and miserable in the cold. If it
doesn't cut all the way through, you'll still have to break it up.
If there's rebar in there, the saw might actually be a big help. Or you
could demo hammer it, cut the rebar w/ a sawzall or oxyacetylene.

I took out a 9" thick poured wall, no rebar, partially w/ a saw, but when
down, just broke it up w/ the big Bosch Demo hammer. Actually didn't take
that long.

With the saw, tho, you could cut nice square blocks, and use it for
something else.
--
------
Mr. P.V.'d (formerly Droll Troll), Yonkers, NY

Stop Corruption in Congress & Send the Ultimate Message:
Absolutely Vote, but NOT for a Democrat or a Republican.
Ending Corruption in Congress is the *Single Best Way*
to Materially Improve Your Family's Life.
The Solution is so simple--and inexpensive!

entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie,
all d'numbuhs

"cerberus" wrote in message
oups.com...
Hi,

I need to demolish an elevated concrete slab deck. It's 8 by 16 and
weighs about 4 tons.

My currrent thinking is to use scaffolding to support the slab while I
carve it up using a concrete saw.

Do you have better ideas?

Thanks.

Jack

cerberus wrote:

Hi,

I need to demolish an elevated concrete slab deck. It's 8 by 16 and
weighs about 4 tons.

My currrent thinking is to use scaffolding to support the slab while I
carve it up using a concrete saw.

Do you have better ideas?

Thanks.

Jack

Sounds like you have an excuse to rent a big toy like a small excavator
with a hydraulic breaker. I recently rented a mid sized Bobcat with a
breaker to obliterate a couple protruding boulders in a gravel driveway.
Made short work of it and had a lot of fun.

Pete C.

cerberus wrote:
Hi,

I need to demolish an elevated concrete slab deck. It's 8 by 16 and
weighs about 4 tons.

My currrent thinking is to use scaffolding to support the slab while I
carve it up using a concrete saw.

Do you have better ideas?

Use expanding concrete in drilled holes to break it up. A hammer drill
and an afternoons work then sit back sip beer while the cement cures and
breaks up the slab.

Google on Dexpan for one brand of expansive demolition agent.



John
--
Remove the dead poet to e-mail, tho CC'd posts are unwelcome.
Mean People Suck - It takes two deviations to get cool.
Ask me about joining the NRA.

Thanks, everyone. It's wonderful to be able to ask a question and get
so much back.

John. I'm interested in expansive demolition although I wonder if they
work when rebar is involved.

Use expanding concrete in drilled holes to break it up. A hammer drill
and an afternoons work then sit back sip beer while the cement cures and
breaks up the slab.

Google on Dexpan for one brand of expansive demolition agent.

In my earlier post I forgot to mention that heavy equipment is out due
to access issues.

cerberus wrote:

Thanks, everyone. It's wonderful to be able to ask a question and get
so much back.

John. I'm interested in expansive demolition although I wonder if they
work when rebar is involved.

Use expanding concrete in drilled holes to break it up. A hammer drill
and an afternoons work then sit back sip beer while the cement cures and
breaks up the slab.

Google on Dexpan for one brand of expansive demolition agent.

In my earlier post I forgot to mention that heavy equipment is out due
to access issues.

I seem to recall "Bentoblast" is one brand name for the bentonite clay
based expansive "blasting" agent. I've seen it stocked at some tool /
equipment rental places.

Even if there is rebar, the bentoblast should fracture the concrete and
if you're lucky collapse the slab, breaking it up further. You should
then be able to go at it with a sledge to get more access to the rebar
and cut them off with an abrasive demo saw. Hauling the debris out if
you can't get heavy equipment in will not be fun.

Pete C.

cerberus wrote:
Thanks, everyone. It's wonderful to be able to ask a question and get
so much back.

John. I'm interested in expansive demolition although I wonder if they
work when rebar is involved.

www.archerusa.com/Product_Dexpan_En1.html

"In demolition. concrete cutting & excavating industry, Dexpan helps you
to break reinforced concrete and rock into chunks, so you may easily cut
off rebar, haul it away with a crane or truck without damage remaining
part"

Use expanding concrete in drilled holes to break it up. A hammer drill
and an afternoons work then sit back sip beer while the cement cures and
breaks up the slab.

Google on Dexpan for one brand of expansive demolition agent.

In my earlier post I forgot to mention that heavy equipment is out due
to access issues.

All the more reason to go with this route: the jackhammer or diamond saw
route will be very messy and loud, not to mention back breaking.


John
--
Remove the dead poet to e-mail, tho CC'd posts are unwelcome.
Mean People Suck - It takes two deviations to get cool.
Ask me about joining the NRA.

So nobody's mentioned the scaffolding idea. It seems necessary since I
want a controlled demolition. I can imagine worst case scenarios where
the slab begins to break up and is no longer supported by it's piers,
but the rebar causes it to slam into my house or, worst, pulls my brick
away from my house.

Any thoughts on a control decent?

Thanks.

Might be a good idea to scaffold, and do an initial saw cut right next to
the house, to completely isolate subsequent operations from the
house--vibration, etc.
But this would require an even stronger scaffolding, as you have introduced
another degree of freedom to the slab.
Places rent this type stuff, bolt-together, or you could build your own, if
you think you might have use for the mat'ls later on.
****, if you were by me, I got a ton of 5x3 I-beams....
--
------
Mr. P.V.'d (formerly Droll Troll), Yonkers, NY

Stop Corruption in Congress & Send the Ultimate Message:
Absolutely Vote, but NOT for a Democrat or a Republican.
Ending Corruption in Congress is the *Single Best Way*
to Materially Improve Your Family's Life.
The Solution is so simple--and inexpensive!

entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie,
all d'numbuhs

"cerberus" wrote in message
oups.com...
So nobody's mentioned the scaffolding idea. It seems necessary since I
want a controlled demolition. I can imagine worst case scenarios where
the slab begins to break up and is no longer supported by it's piers,
but the rebar causes it to slam into my house or, worst, pulls my brick
away from my house.

Any thoughts on a control decent?

Thanks.

On Thu, 16 Nov 2006 16:07:26 -0500, "Proctologically Violated©®"
wrote:

Might be a good idea to scaffold, and do an initial saw cut right next to
the house, to completely isolate subsequent operations from the
house--vibration, etc.
But this would require an even stronger scaffolding, as you have introduced
another degree of freedom to the slab.
Places rent this type stuff, bolt-together, or you could build your own, if
you think you might have use for the mat'ls later on.
****, if you were by me, I got a ton of 5x3 I-beams....


Put an A frame of steel under the edge nearest the house,
saw it loose, and then pull it down with a truck?

I think he might have in mind a scaffolding that would actually cover the
whole area *under* the deck (about 1 foot under), to catch the debris as it
comes off.
--
------
Mr. P.V.'d (formerly Droll Troll), Yonkers, NY

Stop Corruption in Congress & Send the Ultimate Message:
Absolutely Vote, but NOT for a Democrat or a Republican.
Ending Corruption in Congress is the *Single Best Way*
to Materially Improve Your Family's Life.
The Solution is so simple--and inexpensive!

entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie,
all d'numbuhs

"Pete C." wrote in message
...
cerberus wrote:

So nobody's mentioned the scaffolding idea. It seems necessary since I
want a controlled demolition. I can imagine worst case scenarios where
the slab begins to break up and is no longer supported by it's piers,
but the rebar causes it to slam into my house or, worst, pulls my brick
away from my house.

Any thoughts on a control decent?

Thanks.

I think we were kind of going on the assumption that you would make
appropriate cuts first to separate the slab from anything that was
supposed to remain. If the house side needs support where you will cut
it away I'd think just some cut and wedged 2x4s would be adequate and
would safely fall away once the slab started to collapse from the
expansive "blasting". Were it my scaffolding I wouldn't want slab chunks
damaging it. 2x4s are a lot cheaper and more disposable than
scaffolding.

Pete C.

"Proctologically Violated©®" wrote:

I think he might have in mind a scaffolding that would actually cover the
whole area *under* the deck (about 1 foot under), to catch the debris as it
comes off.
--

If that's the case, how will he manage to break up the slab, cut the
rebar and remove the concrete without damaging the scaffolding? It would
need some sort of sacrificial CDX plywood deck on top of it or similar
to protect the scaffolding and that is in all probability not worth the
effort.

Pete C.

That's sorta what I see around here. yeah, some sacrificial stuff,
hopefully it can be used later.
The OP is gonna have to pick one poison or another!
--
------
Mr. P.V.'d (formerly Droll Troll), Yonkers, NY

Stop Corruption in Congress & Send the Ultimate Message:
Absolutely Vote, but NOT for a Democrat or a Republican.
Ending Corruption in Congress is the *Single Best Way*
to Materially Improve Your Family's Life.
The Solution is so simple--and inexpensive!

entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie,
all d'numbuhs

"Pete C." wrote in message
...
"Proctologically Violated©®" wrote:

I think he might have in mind a scaffolding that would actually cover the
whole area *under* the deck (about 1 foot under), to catch the debris as
it
comes off.
--

If that's the case, how will he manage to break up the slab, cut the
rebar and remove the concrete without damaging the scaffolding? It would
need some sort of sacrificial CDX plywood deck on top of it or similar
to protect the scaffolding and that is in all probability not worth the
effort.

Pete C.

cerberus wrote:
Hi,

I need to demolish an elevated concrete slab deck. It's 8 by 16 and
weighs about 4 tons.

My currrent thinking is to use scaffolding to support the slab while I
carve it up using a concrete saw.

Do you have better ideas?

Can't you just paint it or cover it with vines?

HAHAHA. You sound like my wife!

HeyBub wrote:

Can't you just paint it or cover it with vines?

And, yeah, I was think of using rough cut lumber on top of the
scaffolding. By the appearance of the concrete, it looks like that's
how it was poured.

You guys are great! Thanks for all the help!

I'm going to use scaffolding topped with rough lumber, covering the
entire slab bottom. I'll press it up against the slab. I'll use Dexpan
to crack it up. Then I'll use my sawsall to cut the rebar.

Will a little luck I can remove the concrete one square foot at a time.

cerberus wrote:

I'm going to use scaffolding topped with rough lumber, covering the
entire slab bottom. I'll press it up against the slab. I'll use Dexpan
to crack it up. Then I'll use my sawsall to cut the rebar.

Will a little luck I can remove the concrete one square foot at a time.

Forget about using a sawzall to cut rebar, it simply doesn't work, at
least not in any reasonable time frame. Rebar is hard, nasty **** to
cut, trust me, I've tried with a sawzall and good blade and gave up
about 1/4 of the way through a piece of 1/2" rebar. Use an abrasive
cutoff wheel on either an angle grinder, or a demo saw and have plenty
of spare wheels.

Pete C.

Pete C. wrote:
Forget about using a sawzall to cut rebar, it simply doesn't work, at
least not in any reasonable time frame. Rebar is hard, nasty **** to
cut, trust me, I've tried with a sawzall and good blade and gave up
about 1/4 of the way through a piece of 1/2" rebar. Use an abrasive
cutoff wheel on either an angle grinder, or a demo saw and have plenty
of spare wheels.

Or a torch. Torch = more fun.

HeyBub wrote:

Pete C. wrote:
Forget about using a sawzall to cut rebar, it simply doesn't work, at
least not in any reasonable time frame. Rebar is hard, nasty **** to
cut, trust me, I've tried with a sawzall and good blade and gave up
about 1/4 of the way through a piece of 1/2" rebar. Use an abrasive
cutoff wheel on either an angle grinder, or a demo saw and have plenty
of spare wheels.

Or a torch. Torch = more fun.

Yes, however then he will likely set the planks on top of the
scaffolding that the whole slab is resting on on fire which is probably
not a good thing, especially if it's adjacent to his house.

Pete C.

On Fri, 17 Nov 2006 14:35:22 GMT, "Pete C."
wrote:

HeyBub wrote:

Pete C. wrote:
Forget about using a sawzall to cut rebar, it simply doesn't work, at
least not in any reasonable time frame. Rebar is hard, nasty **** to
cut, trust me, I've tried with a sawzall and good blade and gave up
about 1/4 of the way through a piece of 1/2" rebar. Use an abrasive
cutoff wheel on either an angle grinder, or a demo saw and have plenty
of spare wheels.

Or a torch. Torch = more fun.

Yes, however then he will likely set the planks on top of the
scaffolding that the whole slab is resting on on fire which is probably
not a good thing, especially if it's adjacent to his house.



Hell, if he's going to use a torch, he doesn't need to
break up the slab first. Take a torch to the slab,
heat it for a while, then stand back and pour cold water
on it. The slab should pretty much explode by itself.
Then you can just pick up the rebar and chuck it over the
side.

Goedjn wrote:

On Fri, 17 Nov 2006 14:35:22 GMT, "Pete C."
wrote:

HeyBub wrote:

Pete C. wrote:
Forget about using a sawzall to cut rebar, it simply doesn't work, at
least not in any reasonable time frame. Rebar is hard, nasty **** to
cut, trust me, I've tried with a sawzall and good blade and gave up
about 1/4 of the way through a piece of 1/2" rebar. Use an abrasive
cutoff wheel on either an angle grinder, or a demo saw and have plenty
of spare wheels.

Or a torch. Torch = more fun.

Yes, however then he will likely set the planks on top of the
scaffolding that the whole slab is resting on on fire which is probably
not a good thing, especially if it's adjacent to his house.


Hell, if he's going to use a torch, he doesn't need to
break up the slab first. Take a torch to the slab,
heat it for a while, then stand back and pour cold water
on it. The slab should pretty much explode by itself.
Then you can just pick up the rebar and chuck it over the
side.

I'm thinking the cost of fuel gas to do it that way would exceed the
cost of just hiring a company (with insurance) to remove the thing.

Pete C.

On Fri, 17 Nov 2006 17:40:06 GMT, "Pete C."
wrote:

Goedjn wrote:

On Fri, 17 Nov 2006 14:35:22 GMT, "Pete C."
wrote:

HeyBub wrote:

Pete C. wrote:
Forget about using a sawzall to cut rebar, it simply doesn't work, at
least not in any reasonable time frame. Rebar is hard, nasty **** to
cut, trust me, I've tried with a sawzall and good blade and gave up
about 1/4 of the way through a piece of 1/2" rebar. Use an abrasive
cutoff wheel on either an angle grinder, or a demo saw and have plenty
of spare wheels.

Or a torch. Torch = more fun.

Yes, however then he will likely set the planks on top of the
scaffolding that the whole slab is resting on on fire which is probably
not a good thing, especially if it's adjacent to his house.


Hell, if he's going to use a torch, he doesn't need to
break up the slab first. Take a torch to the slab,
heat it for a while, then stand back and pour cold water
on it. The slab should pretty much explode by itself.
Then you can just pick up the rebar and chuck it over the
side.

I'm thinking the cost of fuel gas to do it that way would exceed the
cost of just hiring a company (with insurance) to remove the thing.

Pete C.

Everything's in place, the holes bored and Dexpan installed. It's been
4 hours in 45 degree weather. No sign of cracks yet. It's old concrete
so it's probably hard as my head.

Maybe tomorrow morning it will be wrecked!