I have a section of concrete floor (1-1/2" thick x 60 square feet)
that is fragmented and deflects slightly when I walk on it because the
5/8" plywood subfloor was inadequately fastened to the joists.
To stabilize the concrete, I'm thinking about applying a topping on
it, ideally no more than 3/8" but thicker if necessary.
Can anyone recommend a topping that's trowleable, thin,
crack-resistant/crack-proof and rigid enough to resist deflection from
foot traffic?
Thanks...

wrote:
I have a section of concrete floor (1-1/2" thick x 60 square feet)
that is fragmented and deflects slightly when I walk on it because the
5/8" plywood subfloor was inadequately fastened to the joists.
To stabilize the concrete, I'm thinking about applying a topping on
it, ideally no more than 3/8" but thicker if necessary.
Can anyone recommend a topping that's trowleable, thin,
crack-resistant/crack-proof and rigid enough to resist deflection from
foot traffic?

Sure, it's called pure unobtainium...

Actually, probably about the only thing that would do the trick given
those underlying specifications would be 3/8" steel plate.
--

dpb wrote in :

wrote:
I have a section of concrete floor (1-1/2" thick x 60 square feet)
that is fragmented and deflects slightly when I walk on it because the
5/8" plywood subfloor was inadequately fastened to the joists.
To stabilize the concrete, I'm thinking about applying a topping on
it, ideally no more than 3/8" but thicker if necessary.
Can anyone recommend a topping that's trowleable, thin,
crack-resistant/crack-proof and rigid enough to resist deflection from
foot traffic?

Sure, it's called pure unobtainium...

Actually, probably about the only thing that would do the trick given
those underlying specifications would be 3/8" steel plate.
--



unobtainium

Looks like I need an updated periodic table.

wrote in message
...
I have a section of concrete floor (1-1/2" thick x 60 square feet)
that is fragmented and deflects slightly when I walk on it because the
5/8" plywood subfloor was inadequately fastened to the joists.
To stabilize the concrete, I'm thinking about applying a topping on
it, ideally no more than 3/8" but thicker if necessary.
Can anyone recommend a topping that's trowleable, thin,
crack-resistant/crack-proof and rigid enough to resist deflection from
foot traffic?
Thanks...

There is none. Can you support the weak section from underneath? Fasten
through the existing concrete?

On Oct 15, 8:12�pm, wrote:
I have a section of concrete floor (1-1/2" thick x 60 square feet)
that is fragmented and deflects slightly when I walk on it because the
5/8" plywood subfloor was inadequately fastened to the joists.
To stabilize the concrete, I'm thinking about applying a topping on
it, ideally no more than 3/8" but thicker if necessary.
Can anyone recommend a topping that's trowleable, thin,
crack-resistant/crack-proof and rigid enough to resist deflection from
foot traffic?
Thanks...

rip out existing and replace. anything else will fail probably sooner
rather than later.

so why do you have a concrete floor over plywood?

wrote:
On Oct 15, 8:12�pm, wrote:
I have a section of concrete floor (1-1/2" thick x 60 square feet)
that is fragmented and deflects slightly when I walk on it because the
5/8" plywood subfloor was inadequately fastened to the joists.
To stabilize the concrete, I'm thinking about applying a topping on
it, ideally no more than 3/8" but thicker if necessary.
Can anyone recommend a topping that's trowleable, thin,
crack-resistant/crack-proof and rigid enough to resist deflection from
foot traffic?
Thanks...

rip out existing and replace. anything else will fail probably sooner
rather than later.

so why do you have a concrete floor over plywood?
Probably firebreak. Pretty common in cheap apartment buildings.

--
aem sends...

On Oct 15, 5:12*pm, wrote:
I have a section of concrete floor (1-1/2" thick x 60 square feet)
that is fragmented and deflects slightly when I walk on it because the
5/8" plywood subfloor was inadequately fastened to the joists.
To stabilize the concrete, I'm thinking about applying a topping on
it, ideally no more than 3/8" but thicker if necessary.
Can anyone recommend a topping that's trowleable, thin,
crack-resistant/crack-proof and rigid enough to resist deflection from
foot traffic?
Thanks...


I'm guessing you've got a deteriorated gypcrete situation.....you
"might" be able repair / re-consolidate the fractured crap with a
liquid 2 part epoxy like SIKA Sikadur 35 HI-MOD, LV, LPL.

The stuff ain't cheap, comes in a 3 gal "kit".... total 3 gallon kits
yields about 700 cubic inches of mixed resin.

I'm not sure how you'd calculate or estimate how much you'd need to do
the job but a full kit would give you about 6 ozs per sq ft......

maybe enough re-wet all the cracked pieces & glue them back together?


For my money I'd remove all of it, screw down the plywood & re-pour a
new batch. A successful repair would be a long shot.

cheers
Bob