Hi,

I have a old horse barn that has a floor that is part dirt (where the
stables used to be) and part concrete. The problem it is not half and
half, it is mixed and in places the concrete is cracked and broken.

I want a full slab in the barn to turn it into a shop. However, I
don't want to go through the problem and costs of digging up all the
existing concrete before I pour new. I am also wanting to put in
radiant floor heating.

So is there any process that works for pouring new concrete over old
concrete and having it still adher and be able to take weight of things
like tools or even a car?

Thanks.

Alan

Use some sort of latex adhesive as a bonding agent on top of the old
slab and let sit for an hour or so before pouring the new slab.

Alan wrote:
Hi,

I have a old horse barn that has a floor that is part dirt (where the
stables used to be) and part concrete. The problem it is not half and
half, it is mixed and in places the concrete is cracked and broken.

I want a full slab in the barn to turn it into a shop. However, I
don't want to go through the problem and costs of digging up all the
existing concrete before I pour new. I am also wanting to put in
radiant floor heating.

So is there any process that works for pouring new concrete over old
concrete and having it still adher and be able to take weight of things
like tools or even a car?

Thanks.

Alan

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

I have a old horse barn that has a floor that is part dirt (where the
stables used to be) and part concrete. The problem it is not half and
half, it is mixed and in places the concrete is cracked and broken.


If it is cracked and broken, good chance the slab on top will crack and
break in the same place for the same reason. Find and fix the problem
first.

On 21 Jan 2007 18:36:57 -0800, "Alan" wrote:

Hi,

I have a old horse barn that has a floor that is part dirt (where the
stables used to be) and part concrete. The problem it is not half and
half, it is mixed and in places the concrete is cracked and broken.

I want a full slab in the barn to turn it into a shop. However, I
don't want to go through the problem and costs of digging up all the
existing concrete before I pour new. I am also wanting to put in
radiant floor heating.

So is there any process that works for pouring new concrete over old
concrete and having it still adher and be able to take weight of things
like tools or even a car?

Thanks.

Alan

I would think that if you poured a full thickness 4 inch (or thicker)
slab over the whole thing, it should not matter what is under it, as
long as the old concrete is relatively solid. The problem is whether
the different sections of concrete will allow for getting the whole
floor level. If one section is 6 inches higher than the other, you
may have problems. But if they are all about the same, just pour over
all of it. That old concrete will just add to the strength of the
floor, and you dont really need to adhere the new concrete to it, if
you do a full thickness pour.

I'm no concrete expert, but I have poured some walks and a few garage
and shed floors over the years., and I actually did pour one shed
floor over and an existing shed slab, which was a smaller shed, so the
old floor is only under part of the new one. In the new section I
added some broken chunks of concrete under the new floor so I could
get rid of them. The floor is solid and I never had any problems with
it. I do not drive on it though, it's just a work shed and woodshed
combo.

On Mon, 22 Jan 2007 03:09:06 GMT, "Edwin Pawlowski"
wrote:


"Alan" wrote in message
roups.com...
Hi,

I have a old horse barn that has a floor that is part dirt (where the
stables used to be) and part concrete. The problem it is not half and
half, it is mixed and in places the concrete is cracked and broken.


If it is cracked and broken, good chance the slab on top will crack and
break in the same place for the same reason. Find and fix the problem
first.


This is somewhat true, but some old concrete was poured way to thin.
My old garage floor was apparently poured by someone that did not know
how to use a shovel and rake. In some places it was 10 inches thick,
in others it was only an inch. Of course the one inch parts were
cracked. I no longer live there, but we poured a 4" slab right over
it, and it held up fine for the 6 or 7 years we lived there.

Mike Ryan wrote:
On 21 Jan 2007 18:36:57 -0800, "Alan" wrote:

Hi,

I have a old horse barn that has a floor that is part dirt (where the
stables used to be) and part concrete. The problem it is not half and
half, it is mixed and in places the concrete is cracked and broken.

I want a full slab in the barn to turn it into a shop. However, I
don't want to go through the problem and costs of digging up all the
existing concrete before I pour new. I am also wanting to put in
radiant floor heating.

So is there any process that works for pouring new concrete over old
concrete and having it still adher and be able to take weight of things
like tools or even a car?

Thanks.

Alan

I would think that if you poured a full thickness 4 inch (or thicker)
slab over the whole thing, it should not matter what is under it, as
long as the old concrete is relatively solid. The problem is whether
the different sections of concrete will allow for getting the whole
floor level. If one section is 6 inches higher than the other, you
may have problems. But if they are all about the same, just pour over
all of it. That old concrete will just add to the strength of the
floor, and you dont really need to adhere the new concrete to it, if
you do a full thickness pour.

I'm no concrete expert, but I have poured some walks and a few garage
and shed floors over the years., and I actually did pour one shed
floor over and an existing shed slab, which was a smaller shed, so the
old floor is only under part of the new one. In the new section I
added some broken chunks of concrete under the new floor so I could
get rid of them. The floor is solid and I never had any problems with
it. I do not drive on it though, it's just a work shed and woodshed
combo.

Where is the project located?

If you're located where you need heat, I would suggest removing the old
concrete & doing the whole this right.

W/o proper insulation you'll be heating the earth as well as the shop.

Might consider a wood stove or a gas fired blower.

How many sq ft of old concrete are we talking about 200? 500?

500 sq ft is only about 5 yds not a huge task to remove. IMO remove
the old stuff it will be easier to work on a clean pallet rather than
piecing the floor together.

How good do you want the new floor to be? How long do you want the new
floor to last?

Any vehicle traffic on the new floor? HEAVY (1000's of #'s)
machines?

How long was the horse barn a horse barn? Animal urine in the dirt
can give new concrete problems.....investigate sulfate attack of
concrete.

If you want the new floor to perform well you need a good base.

Do you have a concrete disposal (grinder) site near by? Your old floor
can be your base material.


cheers
Bob

if your going to drive on it, then rip out all the old concrete and
start over. otherwise its guaranteed to crack, plus you need a good
base with all topsoil removed and several inches of gravel under
everything and ideally a vapor barrier to keep out moisture. if your
converting to a shop radiant floor heating is a good option.

a halfway patch job will long term just waste money

rent a bobcat to do the heavy work, kinda fun and saves lots of back
breaking work

Having just completed a slab with radiant tubing in it, I HIGHLY recommend
you remove all the old concrete and do it up properly. Since you won't be
able to saw control into the slab, you'll want 1/2" rebar on 2' centers in
both directions to minimize cracking. I would hesitate pouring the slab if
freezing weather is in the forecast within 2 weeks of the pour. If you can
get your radiant system up and running before the slab freezes, then all the
better. No chance of heaving. Be sure to insulate under the rebar, and
put the tubing on top of it. You'll need a flatwork crew familiar with the
tubing process, and at least a 5" slab. This way they can still pull the
rebar up near the center of the slab and still have ample concrete on top of
the tubing.

--
Steve Barker


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

I have a old horse barn that has a floor that is part dirt (where the
stables used to be) and part concrete. The problem it is not half and
half, it is mixed and in places the concrete is cracked and broken.

I want a full slab in the barn to turn it into a shop. However, I
don't want to go through the problem and costs of digging up all the
existing concrete before I pour new. I am also wanting to put in
radiant floor heating.

So is there any process that works for pouring new concrete over old
concrete and having it still adher and be able to take weight of things
like tools or even a car?

Thanks.

Alan

Remove all the old concrete first.

On 21 Jan 2007 18:36:57 -0800, "Alan" wrote:

Hi,

I have a old horse barn that has a floor that is part dirt (where the
stables used to be) and part concrete. The problem it is not half and
half, it is mixed and in places the concrete is cracked and broken.

I want a full slab in the barn to turn it into a shop. However, I
don't want to go through the problem and costs of digging up all the
existing concrete before I pour new. I am also wanting to put in
radiant floor heating.

So is there any process that works for pouring new concrete over old
concrete and having it still adher and be able to take weight of things
like tools or even a car?

Thanks.

Alan

4" new concrete imbedded with 6x6-10-10 welded wire mesh. Concrete
should be 3,500 or 4,000PSI.

On 21 Jan 2007 18:36:57 -0800, "Alan" wrote:

Hi,

I have a old horse barn that has a floor that is part dirt (where the
stables used to be) and part concrete. The problem it is not half and
half, it is mixed and in places the concrete is cracked and broken.

I want a full slab in the barn to turn it into a shop. However, I
don't want to go through the problem and costs of digging up all the
existing concrete before I pour new. I am also wanting to put in
radiant floor heating.

So is there any process that works for pouring new concrete over old
concrete and having it still adher and be able to take weight of things
like tools or even a car?

Thanks.

Alan

I would think that if you poured a full thickness 4 inch (or thicker)
slab over the whole thing, it should not matter what is under it, as
long as the old concrete is relatively solid. The problem is whether
the different sections of concrete will allow for getting the whole
floor level. If one section is 6 inches higher than the other, you
may have problems. But if they are all about the same, just pour over
all of it. That old concrete will just add to the strength of the
floor, and you dont really need to adhere the new concrete to it, if
you do a full thickness pour.

I'm no concrete expert, but I have poured some walks and a few garage
and shed floors over the years., and I actually did pour one shed
floor over and an existing shed slab, which was a smaller shed, so the
old floor is only under part of the new one. In the new section I
added some broken chunks of concrete under the new floor so I could
get rid of them. The floor is solid and I never had any problems with
it. I do not drive on it though, it's just a work shed and woodshed
combo.

I would think that if you poured a full thickness 4 inch (or thicker)
slab over the whole thing, it should not matter what is under it, as
long as the old concrete is relatively solid. The problem is whether
the different sections of concrete will allow for getting the whole
floor level. If one section is 6 inches higher than the other, you
may have problems. But if they are all about the same, just pour over
all of it. That old concrete will just add to the strength of the
floor, and you dont really need to adhere the new concrete to it, if
you do a full thickness pour.

some areas will sink under the weight of a vehicle and the entire thing
will crack, espical;ly where existing concrete is