A couple years ago I had to dig up my foundation, and despite our best
efforts at machine tamping to 'refusal'- it apparently wasn't enough.

So now the slab for my oil barrel is pitched 1/2 inch towards the
house. If it went the other way, I'd just watch it-- but I'd like
to correct it as it is bound to get worse. The slab is 3-4"thick and
3'x6'.

I can lift the slab at the two low corners and get it back to level-
and will pitch it away from the house. But what is the best way
to try to get a slurry under as much of the slab as possible.

My first thoughts are to;
1. make roughly 8" square access holes a foot deep on the 2 low
corners -
2. jack to level-
3. enclose the 'piers' and most of the back side - leaving a space in
the center.
4. fill with a loose slurry until it begins to ooze from the center.

I have access to a concrete vibrator- but I have only seen one in use
once and I'm not sure if it will work here.

What are my chances that this will keep this slab more-or-less in
place for a few more years? [I'm in NY- btw- so frost will guarantee
that it will never stay exactly where I put it- I'm just trying to
get it to be 'off' in the right direction.]

Thanks,
Jim

Abe wrote:

A couple years ago I had to dig up my foundation, and despite our best
efforts at machine tamping to 'refusal'- it apparently wasn't enough.

So now the slab for my oil barrel is pitched 1/2 inch towards the
house. If it went the other way, I'd just watch it-- but I'd like
to correct it as it is bound to get worse. The slab is 3-4"thick and
3'x6'.

I can lift the slab at the two low corners and get it back to level-
and will pitch it away from the house. But what is the best way
to try to get a slurry under as much of the slab as possible.

My first thoughts are to;
1. make roughly 8" square access holes a foot deep on the 2 low
corners -
2. jack to level-
Any chance you could make the jacks permanent and adjust them as
needed?

If it's the usual 275-330 gal tank with pipe legs, just get four of the
standard scaffold screw jacks and some suitable washers and install them
into the pipe legs so you can just adjust them as needed and not care if
the slab is a little out of level.

"Jim Elbrecht" wrote in message
...
A couple years ago I had to dig up my foundation, and despite our
best
efforts at machine tamping to 'refusal'- it apparently wasn't
enough.

So now the slab for my oil barrel is pitched 1/2 inch towards the
house. If it went the other way, I'd just watch it-- but I'd
like
to correct it as it is bound to get worse. The slab is 3-4"thick
and
3'x6'.

I can lift the slab at the two low corners and get it back to level-
and will pitch it away from the house. But what is the best way
to try to get a slurry under as much of the slab as possible.

My first thoughts are to;
1. make roughly 8" square access holes a foot deep on the 2 low
corners -
2. jack to level-
3. enclose the 'piers' and most of the back side - leaving a space
in
the center.
4. fill with a loose slurry until it begins to ooze from the
center.

I have access to a concrete vibrator- but I have only seen one in
use
once and I'm not sure if it will work here.

What are my chances that this will keep this slab more-or-less in
place for a few more years? [I'm in NY- btw- so frost will
guarantee
that it will never stay exactly where I put it- I'm just trying to
get it to be 'off' in the right direction.]

I just leveled a concrete hot tub/spa. I jacked it up, then pumped
fairly fluid grout under it using a hand powered grout pump I bought
second hand. I connected the pump output to 3/4" pvc pipe and slipped
that under the slab, built a wall around the edge, and pumped until it
came back out, and then some.

Bob

On Jul 3, 5:23 pm, "Bob F" wrote:
"Jim Elbrecht" wrote in message

...





A couple years ago I had to dig up my foundation, and despite our
best
efforts at machine tamping to 'refusal'- it apparently wasn't
enough.

So now the slab for my oil barrel is pitched 1/2 inch towards the
house. If it went the other way, I'd just watch it-- but I'd
like
to correct it as it is bound to get worse. The slab is 3-4"thick
and
3'x6'.

I can lift the slab at the two low corners and get it back to level-
and will pitch it away from the house. But what is the best way
to try to get a slurry under as much of the slab as possible.

My first thoughts are to;
1. make roughly 8" square access holes a foot deep on the 2 low
corners -
2. jack to level-
3. enclose the 'piers' and most of the back side - leaving a space
in
the center.
4. fill with a loose slurry until it begins to ooze from the
center.

I have access to a concrete vibrator- but I have only seen one in
use
once and I'm not sure if it will work here.

What are my chances that this will keep this slab more-or-less in
place for a few more years? [I'm in NY- btw- so frost will
guarantee
that it will never stay exactly where I put it- I'm just trying to
get it to be 'off' in the right direction.]

I just leveled a concrete hot tub/spa. I jacked it up, then pumped
fairly fluid grout under it using a hand powered grout pump I bought
second hand. I connected the pump output to 3/4" pvc pipe and slipped
that under the slab, built a wall around the edge, and pumped until it
came back out, and then some.

Bob- Hide quoted text -

- Show quoted text -

I've seen them level a sinking corner of an office building slab by
underdigging down about 24", pour a small 4" slab, let it dry, insert
several jacks between the new & old slabs, get the old slab level,
then fill the whole thing with concrete leaving the jacks imbedded in
the concrete. A real red-neck fix but it worked.

KC

On Tue, 03 Jul 2007 12:53:36 -0700, Abe wrote:
-snip-
Any chance you could make the jacks permanent and adjust them as
needed?

I considered that- but it will leave me with a much smaller footprint
that is more likely to sink again. By filling the air gap with
grout/mortar, I at least stand a chance that I might not have to do
this job again. [or so I hope]

Thanks-

Jim

On Tue, 03 Jul 2007 16:02:26 -0500, "Pete C."
wrote:

-snip-
If it's the usual 275-330 gal tank with pipe legs, just get four of the
standard scaffold screw jacks and some suitable washers and install them
into the pipe legs so you can just adjust them as needed and not care if
the slab is a little out of level.

I don't mind the slight out of level as much as I don't like it
dumping the runoff towards my house. There is about a foot gap- but
it just isn't a good place to have extra water.

If the slab was pitched away from the house I'd be getting 2 screw
jacks.

Thanks-
Jim

"Bob F" wrote:

-snip-
I just leveled a concrete hot tub/spa. I jacked it up, then pumped
fairly fluid grout under it using a hand powered grout pump I bought
second hand. I connected the pump output to 3/4" pvc pipe and slipped
that under the slab, built a wall around the edge, and pumped until it
came back out, and then some.

Super! I looked at them on ebay--- think I'll call a rental place
thursday. They seem pretty dear for a simple pump. [$500 for a
5gallon- no used ones today]

Hmmm- - same brother-in-law who has the vibrator might have one in his
barn.

Good idea- thanks.
Jim

KC wrote:

-snip-
I've seen them level a sinking corner of an office building slab by
underdigging down about 24", pour a small 4" slab, let it dry, insert
several jacks between the new & old slabs, get the old slab level,
then fill the whole thing with concrete leaving the jacks imbedded in
the concrete. A real red-neck fix but it worked.

I'm making a much smaller hole- and trading out my jack for a chunk of
galvanized pipe- but in general that's my plan.

Now to find that grout pump. . . .

Jim

"Jim Elbrecht" wrote in message
...
"Bob F" wrote:

-snip-
I just leveled a concrete hot tub/spa. I jacked it up, then pumped
fairly fluid grout under it using a hand powered grout pump I bought
second hand. I connected the pump output to 3/4" pvc pipe and
slipped
that under the slab, built a wall around the edge, and pumped until
it
came back out, and then some.

Super! I looked at them on ebay--- think I'll call a rental
place
thursday. They seem pretty dear for a simple pump. [$500 for a
5gallon- no used ones today]

Hmmm- - same brother-in-law who has the vibrator might have one in
his
barn.

Good idea- thanks.

It'll be interesting if you find a rental. I couldn't in Seattle. So I
went for the one on craigslist.

Bob

KC wrote in
oups.com:

On Jul 3, 5:23 pm, "Bob F" wrote:
"Jim Elbrecht" wrote in message

...





A couple years ago I had to dig up my foundation, and despite our
best
efforts at machine tamping to 'refusal'- it apparently wasn't
enough.

So now the slab for my oil barrel is pitched 1/2 inch towards the
house. If it went the other way, I'd just watch it-- but I'd
like
to correct it as it is bound to get worse. The slab is 3-4"thick
and
3'x6'.

I can lift the slab at the two low corners and get it back to level-
and will pitch it away from the house. But what is the best way
to try to get a slurry under as much of the slab as possible.

My first thoughts are to;
1. make roughly 8" square access holes a foot deep on the 2 low
corners -
2. jack to level-
3. enclose the 'piers' and most of the back side - leaving a space
in
the center.
4. fill with a loose slurry until it begins to ooze from the
center.

I have access to a concrete vibrator- but I have only seen one in
use
once and I'm not sure if it will work here.

What are my chances that this will keep this slab more-or-less in
place for a few more years? [I'm in NY- btw- so frost will
guarantee
that it will never stay exactly where I put it- I'm just trying to
get it to be 'off' in the right direction.]

I just leveled a concrete hot tub/spa. I jacked it up, then pumped
fairly fluid grout under it using a hand powered grout pump I bought
second hand. I connected the pump output to 3/4" pvc pipe and slipped
that under the slab, built a wall around the edge, and pumped until it
came back out, and then some.

Bob- Hide quoted text -

- Show quoted text -

I've seen them level a sinking corner of an office building slab by
underdigging down about 24", pour a small 4" slab, let it dry, insert
several jacks between the new & old slabs, get the old slab level,
then fill the whole thing with concrete leaving the jacks imbedded in
the concrete. A real red-neck fix but it worked.

KC


To raise your slab,drill holes for expansion anchors,place bridging beams
(4x4s)across the slab with holes drilled for threaded rods that screw into
the anchors,and put washers and nuts on the other end of the threaded
rods.Tighten the nuts to raise the slab. Then you can pour some concrete
slurry under the slab to keep it up.

--
Jim Yanik
jyanik
at
kua.net