If you can get the surfaces clean and dry then you should use Bostick 1100
FS. It is usually only available from construction suppliers, not the home
stores. It sticks to concrete very well and it stays flexible permanently.
I forget the stretch ratio but I think it may be as much as 25% to 40%. So
a 1 inch crack could open to 1.25 or 1.40 inches and it would not tear. Tar
will get hard and then it won't stretch at all so if the concrete moves at
all it will open the crack again beside the tar. Be careful with the
Bostick as any messes must be cleaned up right away with acetone or they
will be permanent stains or lumps. It comes in normal size tubes so you
could do it yourself. It is quite thick so if you have a lot to do it is
hard on the wrists. I had a lot to do so I got a $20 power caulking gun
that runs on compressed air. Needed a lot of adjusting of the air pressure
so it wouldn't shoot out an entire tube in a few seconds.

les wrote:
I have a concrete patio that consists of 4 sections, about 10 feet square
each,
and they are slightly shifting to create 1/2" spaces between them, and the
house
foundation too. (you can't see how far down the crack goes. seems deep)
I had a tuckpointer here, and he mentioned that besides the work I
originally
called him about, he could fix this as well.
As you can imagine, constant rainfall and freezing weather washes away dirt
under
the slabs, so over time I'm afraid this will get worse.
The house (and maybe the slabs) are about 50 years old, and we live in the
Midwest
over clay soil. There is other evidence of shifting soil around here.

The tuckpointer said he'd use hot tar to seal things up in between the
spaces.
I wonder if that's a reasonable fix, or if I could use another material,
perhaps even
myself, to get a good result.
Would silicon work in this situation? Other sealants?

LB


Tar works. If you don't like black, there is flexible caulk for your
specific purpose...check out the big box store. I would not want
tuckpointing for a patio where it freezes...should have some flex.

I have a concrete patio that consists of 4 sections, about 10 feet square
each,
and they are slightly shifting to create 1/2" spaces between them, and the
house
foundation too. (you can't see how far down the crack goes. seems deep)
I had a tuckpointer here, and he mentioned that besides the work I
originally
called him about, he could fix this as well.
As you can imagine, constant rainfall and freezing weather washes away dirt
under
the slabs, so over time I'm afraid this will get worse.
The house (and maybe the slabs) are about 50 years old, and we live in the
Midwest
over clay soil. There is other evidence of shifting soil around here.

The tuckpointer said he'd use hot tar to seal things up in between the
spaces.
I wonder if that's a reasonable fix, or if I could use another material,
perhaps even
myself, to get a good result.
Would silicon work in this situation? Other sealants?

LB

On 07/10/2010 12:48 PM, DanG wrote:
Hot tar is the old original standby. Current technology demands
cleaning the concrete, installing backer rod to control the shape
of the fill, and careful installation of one of the polyurethane
caulks. Sonneborn's NP1 is a good one, use Vulkem or SL1 if you
want to use self leveling material - your joints need to be fairly
level for these to work, it really does seek level. There are
some excellent 2 part silicone products, but the application
kettles and equipment would not be feasible for a one time use.


Just curious, do these work like silicone caulks where if you use them
once you can't go back to the old school stuff because nothing else will
adhere to the substrate?

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On Jul 7, 7:21*pm, "les" wrote:
I have a concrete patio that consists of 4 sections, about 10 feet square
each,
and they are slightly shifting to create 1/2" spaces between them, and the
house
foundation too. (you can't see how far down the crack goes. seems deep)
I had a tuckpointer here, and he mentioned that besides the work I
originally
called him about, he could fix this as well.
As you can imagine, constant rainfall and freezing weather washes away dirt
under
the slabs, so over time I'm afraid this will get worse.
The house (and maybe the slabs) are about 50 years old, and we live in the
Midwest
over clay soil. There is other evidence of shifting soil around here.

The tuckpointer said he'd use hot tar to seal things up in between the
spaces.
I wonder if that's a reasonable fix, or if I could use another material,
perhaps even
myself, to get a good result.
Would silicon work in this situation? Other sealants?

LB

They make backer foam rods and caulk for your problem. I believe you
can get it at lowes. Comes in those bigger caulk tubes.

Hot tar is the old original standby. Current technology demands
cleaning the concrete, installing backer rod to control the shape
of the fill, and careful installation of one of the polyurethane
caulks. Sonneborn's NP1 is a good one, use Vulkem or SL1 if you
want to use self leveling material - your joints need to be fairly
level for these to work, it really does seek level. There are
some excellent 2 part silicone products, but the application
kettles and equipment would not be feasible for a one time use.

--
~~~~~~~~~~~~~~~~~~~~
DanG
Keep the whole world singing . . .


"les" wrote in message
net...
I have a concrete patio that consists of 4 sections, about 10
feet square
each,
and they are slightly shifting to create 1/2" spaces between
them, and the
house
foundation too. (you can't see how far down the crack goes.
seems deep)
I had a tuckpointer here, and he mentioned that besides the work
I
originally
called him about, he could fix this as well.
As you can imagine, constant rainfall and freezing weather
washes away dirt
under
the slabs, so over time I'm afraid this will get worse.
The house (and maybe the slabs) are about 50 years old, and we
live in the
Midwest
over clay soil. There is other evidence of shifting soil around
here.

The tuckpointer said he'd use hot tar to seal things up in
between the
spaces.
I wonder if that's a reasonable fix, or if I could use another
material,
perhaps even
myself, to get a good result.
Would silicon work in this situation? Other sealants?

LB

"jamesgangnc" wrote in message
...


They make backer foam rods and caulk for your problem. I
believe you
can get it at lowes. Comes in those bigger caulk tubes.

If you can't get the backer foam, just buy a pool "noodle" and cut
strips out of it lengthwise. All it's for is to limit the depth
of the crack so you won't use so much elastomeric filler.

Nonny

--
On most days,
it's just not worth
the effort of chewing
through the restraints..