Ok - I'm doing something wrong but what?
This is really frustrating and beginning to
tick me off.

I recently damp proofed an "old" section of
the garage that worked out really well - see....

www.gillandroy.com/diy/StoreroomFinished

However the floor was a bit of a problem.
All worked out well in the end but only after
some backbreaking hours.

I used a Cement Based Leveling Compound/SBR
mixture. Evidently the SBR makes the mixture
waterproof, more workable, flexible and stronger.
The problem I had was bubbles in the mixture when
laid. These popped and left craters in the finished
surface. I'm not talking about the odd one here and
there... It was literally covered! see...

www.gillandroy.com/diy/craters

This was put down to over entheusiastic mixing
with one of these...

http://www.screwfix.com/app/sfd/cat/...52400&ts=03505

I spent hours down on my knees filling each hole
by hand.

So when I came to next section I decided to mix by
hand. Small shovel in a builders tug...

Guess what - exacly the same - bubbles and craters. More
hours kneeling/filling... Hmmm...

More discussion with the vendor of the stuff..

Ok - do the mixing then let it settle in the tug for a while...
also buy a spiked roller from a builders merchant and use
that--- then you'll be ok...

Well none of the builders merchants had a clue about
a spiked roller... But I managed to buy one from here...

www.industrial-flooring.co.uk

See picture here...

www.gillandroy.com/diy/spiker

I have just done one further bag on the next section...
mixture left to settle, then pour, spread with trowel.
As bubbles start to appear splat them with the roller...
Great - but hang on.. they re-appear... In fact the roller
seem to have just about zero effect...

Is there an expert out there that can tell me what I'm
doing wrong!!!!!! Please!!!

Roy

You're pulling our leg? thats a good shot of the moons surface. ;-)
http://www.gillandroy.com/diy/craters



--
Sir Benjamin Middlethwaite

"The3rd Earl Of Derby" wrote in message
k...

You're pulling our leg? thats a good shot of the moons surface. ;-)
http://www.gillandroy.com/diy/craters

Sir Benjamin Middlethwaite


Yes - I thought that myself....:-) but...

Honest it's the floor... not only that but it's
not the worst part either.... Some parts are
more craters than non-craters !!!

Help!!
Roy

GzB wrote:
"The3rd Earl Of Derby" wrote in message
k...

You're pulling our leg? thats a good shot of the moons surface. ;-)
http://www.gillandroy.com/diy/craters

Sir Benjamin Middlethwaite


Yes - I thought that myself....:-) but...

Honest it's the floor... not only that but it's
not the worst part either.... Some parts are
more craters than non-craters !!!

Help!!
Roy


Have you thought for one moment it might be the product is a load of erm!
dog muck? considering they ask you to buy a needle roller if this occurs.

I've laid a floor in similair stuff and havn't had experienced craters or
bubbles in the mix.
--
Sir Benjamin Middlethwaite

On Tue, 27 Dec 2005 18:30:43 -0000, "RzB"
wrote:


This was put down to over entheusiastic mixing
with one of these...

http://www.screwfix.com/app/sfd/cat/...52400&ts=03505

You paid HOW MUCH????!!!!

I use a bit of old bent coathanger in a cordless drill.

sponix

sponix wrote:
On Tue, 27 Dec 2005 18:30:43 -0000, "RzB"
wrote:


This was put down to over entheusiastic mixing
with one of these...

http://www.screwfix.com/app/sfd/cat/...52400&ts=03505

You paid HOW MUCH????!!!!

I use a bit of old bent coathanger in a cordless drill.

sponix

Oh! do be realistic.

I paid £2.99 for my mixing paddle from the local diy shop not shed, I
thought he was going to ask a silly price like £8 or more.

--
Sir Benjamin Middlethwaite

On Tue, 27 Dec 2005 18:30:43 -0000, RzB wrote:

Ok - I'm doing something wrong but what?
This is really frustrating and beginning to
tick me off.

Try damping the floor well before laying the levelling compound. When I put
some down on a rather porous concrete floor, if the concrete wasn't damp
almost to the point of standing water, the water from the mix soaked into
the concrete, to be replaced by air bubbles from below.

John,

Yes, yes - floor was well damped prior to pouring compound...

Roy

Ok, ok - that was just the first picture I could
find as an example of what I used......

Of course I would never spend that much on
a tool that could so obviously be fashion
from a coat hanger... :-)

The question is... why the bubbles and what am
I doing wrong... ?

Roy

RzB wrote:
Ok, ok - that was just the first picture I could
find as an example of what I used......

Of course I would never spend that much on
a tool that could so obviously be fashion
from a coat hanger... :-)

The question is... why the bubbles and what am
I doing wrong... ?

Roy

I've given you my argument, what are you mixing it in? and did you degrease
the floor before laying or it might be the fact the tempreture ie very cold
floor?
--
Sir Benjamin Middlethwaite

I've given you my argument, what are you mixing it in? and did you
degrease
the floor before laying or it might be the fact the tempreture ie very
cold
floor?
--
Sir Benjamin Middlethwaite


Mixing in a builders trug... large plastic "bucket"
like this , but yellow...

http://tinyurl.com/arbf4

Hmm - No didn't degrease the floor. There was no
grease on the floor to degrease.. So I and vendor of
"stuff" decided that was not necessary.

Now interesting that you bring up temperature....
Yes it was quite cold today in the garage...about
6degC... However, the stuff I did earlier was at a
much higher temp - probably about 15+deg C... so
not sure that temp is a contributing factor...

Thanks for your thoughts...
Roy

"RzB" wrote in message
...
John,

Yes, yes - floor was well damped prior to pouring compound...

Roy

Hmm - but it's an interesting thought of how
the bubbles might be forming...

Hmmm - mind buzzing on this one...

I didn't actually have "standing" water... but it was
well soaked...

I wonder if it would be worth trying with a bit more
damping... Hmmm...

Might give this a try...

Thanks,
Roy

"RzB" wrote in message
...

"RzB" wrote in message
...
John,

Yes, yes - floor was well damped prior to pouring compound...

Roy

Hmm - but it's an interesting thought of how
the bubbles might be forming...

Hmmm - mind buzzing on this one...

I didn't actually have "standing" water... but it was
well soaked...

I wonder if it would be worth trying with a bit more
damping... Hmmm...

Might give this a try...

Thanks,
Roy
Just a thought, try a second thinner coat spread with a steel float on a
small test area. this might be the answer to filling in the holes.

RzB wrote in message
...
Ok - I'm doing something wrong but what?
This is really frustrating and beginning to
tick me off.

Explain exactly how you are mixing this.
From your Pic it looks like you are either whisking the mix _far_ too fast
or dumping all the power into the water in one go, and then not Stirring
_gently_ until _all_ the lumps have gone.


-

The3rd Earl Of Derby wrote:
I paid £2.99 for my mixing paddle from the local diy shop not shed, I
thought he was going to ask a silly price like £8 or more.

But this is no ordinary mixing paddle, this is a hand crafted, toledo steel,
designer label mixing paddle. I bet Andy Hall has one.............

:-)

Dave

RzB wrote:

Ok - I'm doing something wrong but what?
This is really frustrating and beginning to
tick me off.

I recently damp proofed an "old" section of
the garage that worked out really well - see....

www.gillandroy.com/diy/StoreroomFinished

However the floor was a bit of a problem.
All worked out well in the end but only after
some backbreaking hours.

I used a Cement Based Leveling Compound/SBR
mixture. Evidently the SBR makes the mixture
waterproof, more workable, flexible and stronger.
The problem I had was bubbles in the mixture when
laid. These popped and left craters in the finished
surface. I'm not talking about the odd one here and
there... It was literally covered! see...

www.gillandroy.com/diy/craters

This was put down to over entheusiastic mixing
with one of these...

http://www.screwfix.com/app/sfd/cat/...52400&ts=03505

I spent hours down on my knees filling each hole
by hand.

So when I came to next section I decided to mix by
hand. Small shovel in a builders tug...

Guess what - exacly the same - bubbles and craters. More
hours kneeling/filling... Hmmm...

More discussion with the vendor of the stuff..

Ok - do the mixing then let it settle in the tug for a while...
also buy a spiked roller from a builders merchant and use
that--- then you'll be ok...

Well none of the builders merchants had a clue about
a spiked roller... But I managed to buy one from here...

www.industrial-flooring.co.uk

See picture here...

www.gillandroy.com/diy/spiker

I have just done one further bag on the next section...
mixture left to settle, then pour, spread with trowel.
As bubbles start to appear splat them with the roller...
Great - but hang on.. they re-appear... In fact the roller
seem to have just about zero effect...

Is there an expert out there that can tell me what I'm
doing wrong!!!!!! Please!!!

Cars drip water. Put a tray under the engine (if you see a liquid when
you reverse out you have a problem).

I wouldn't have sealed it.

--
zaax

On Wed, 28 Dec 2005 00:43:12 GMT, "david lang"
wrote:

The3rd Earl Of Derby wrote:
I paid £2.99 for my mixing paddle from the local diy shop not shed, I
thought he was going to ask a silly price like £8 or more.

But this is no ordinary mixing paddle, this is a hand crafted, toledo steel,
designer label mixing paddle. I bet Andy Hall has one.............

:-)

Good heavens no. Mine's stainless.....


--

..andy

In message , Andy Hall
writes
On Wed, 28 Dec 2005 00:43:12 GMT, "david lang"
wrote:

The3rd Earl Of Derby wrote:
I paid £2.99 for my mixing paddle from the local diy shop not shed, I
thought he was going to ask a silly price like £8 or more.

But this is no ordinary mixing paddle, this is a hand crafted, toledo steel,
designer label mixing paddle. I bet Andy Hall has one.............

:-)

Good heavens no. Mine's stainless.....

Not gold plated then, ... cheapskate

--
geoff

RzB wrote:

The question is... why the bubbles and what am
I doing wrong... ?

You used too much Fairy Liquid.

Steer clear of fairies next time. (Personally I'd bury them good and
deep.)

If you had allowed the air to vent by standing it for a shrt while you
would have been better off. But I think if you had worked the floor as
you laid it, concentrating on something like 18" wide strips perhaps?

How stiff was your mix?

"Weatherlawyer" wrote in message
oups.com...

RzB wrote:

The question is... why the bubbles and what am
I doing wrong... ?

You used too much Fairy Liquid.

Steer clear of fairies next time. (Personally I'd bury them good and
deep.)

Of course, of course.. :-)


If you had allowed the air to vent by standing it for a shrt while you
would have been better off.

Yes - did that... left it to stand for 10+mins

But I think if you had worked the floor as
you laid it, concentrating on something like 18" wide strips perhaps?

Yes - that's how it was done.. a 25kg bag mixed at a time.
Then a strip poured and worked into place with a trowel..
then another pour and working with trowel.

Within 10secs of the mixture laying on the surface
untouched, bubbles start popping up and forming craters.
Further trowling - goes nice and flat then another 10secs
and bubbles/craters.


How stiff was your mix?


Have tried all sorts from stiffish to runny. All pourable.

Roy

Just a thought, try a second thinner coat spread with a steel float on a
small test area. this might be the answer to filling in the holes.

Keith,

No - tried that. I found the only effective
way to fill the holes is to use a wallpaper
scraper type tool. Mix up a small amount
of "stuff", and press it into the holes.
Then wait for the holes to cave in and
press it in some more...
Tedious, very tedious.

Roy

RzB wrote:
Just a thought, try a second thinner coat spread with a steel float
on a small test area. this might be the answer to filling in the
holes.

Keith,

No - tried that. I found the only effective
way to fill the holes is to use a wallpaper
scraper type tool. Mix up a small amount
of "stuff", and press it into the holes.
Then wait for the holes to cave in and
press it in some more...
Tedious, very tedious.

Roy

So you have covered all areas as to what the problem might be and laid it
to the manufacturers instructions?
my guess its just a crap product.

--
Sir Benjamin Middlethwaite

On Wed, 28 Dec 2005 11:04:32 -0000, "RzB"
wrote:



Within 10secs of the mixture laying on the surface
untouched, bubbles start popping up and forming craters.
Further trowling - goes nice and flat then another 10secs
and bubbles/craters.

Could it be air being released from pores in the concrete?

Often garage floors are not poured with the most TLC or the best
concrete....

I wonder whether some dilute PVA put on first would help....


--

..andy

"Mark" wrote in message
...

RzB wrote in message
...
Ok - I'm doing something wrong but what?
This is really frustrating and beginning to
tick me off.

Explain exactly how you are mixing this.
From your Pic it looks like you are either whisking the mix _far_ too fast
or dumping all the power into the water in one go, and then not Stirring
_gently_ until _all_ the lumps have gone.

Mark,
Many thanks for your help.

NB. The "lumps" in the picture are not
because the mixture has not been mixed
thoroughly. They are bubbles that have
not quite popped...

I have tried a number of methods...

I'm using a mixture of 3 parts water
to 1 part SBR. I mix this first in a number
of 4 pint plastic containers.

I then take a 25kg bag of the Leveling
Compound and put it into a large Trug...

I have tried a number of methods of mixing
the two together. My first efforts used a mixer
attached to a drill. I would add about 4 pints
of the liquid to the compound and stir till
all the liquid was taken up. Then add more
liquid and stir etc.. This was continued till
the mixture was smooth with no lumps.

I too thought that perhaps the mixing method
had caused too much air to be introduced,
hence the bubbles.

However I have since mixed carefully by
hand, using a small shovel. But the result
was exactly the same... bubbles & craters.

Thanks,
Roy

So you have covered all areas as to what the problem might be and laid it
to the manufacturers instructions?
my guess its just a crap product.
Sir Benjamin Middlethwaite


Hmm.. - I'm beginning to come to that
conclusion myself...

Do I take it that this is not an unusual mixture?

Cement Based Leveling Compound and SBR?

Have others used this mixture without problems?

Perhaps I should try a bag without the SBR
to see if it's some kind if interraction between
the compound and the SBR.

Many thanks,
Roy

"Andy Hall" wrote in message
...

Within 10secs of the mixture laying on the surface
untouched, bubbles start popping up and forming craters.
Further trowling - goes nice and flat then another 10secs
and bubbles/craters.

Could it be air being released from pores in the concrete?

Often garage floors are not poured with the most
TLC or the best concrete....

I wonder whether some dilute PVA put on first
would help....

.andy

Andy,

That's a good thought, but on the first
section I did make a mistake. I did
indeed put down a dilute PVA solution.
My mistake was that I let it dry hard.
This is evidently a no no because it stops
a good bond forming between the concrete
and the levelling compound.

This should not be a problem in the first
section as it is going to be a store room,
with little traffic.

But that would have most certainly have
stopped any bubbles coming up from pores
in the concrete. But I still got bubbles...

Thanks,
Roy

On Wed, 28 Dec 2005 12:43:09 -0000, "RzB"
wrote:



That's a good thought, but on the first
section I did make a mistake. I did
indeed put down a dilute PVA solution.
My mistake was that I let it dry hard.
This is evidently a no no because it stops
a good bond forming between the concrete
and the levelling compound.

This should not be a problem in the first
section as it is going to be a store room,
with little traffic.

But that would have most certainly have
stopped any bubbles coming up from pores
in the concrete. But I still got bubbles...


Hmm.... It is starting to look like a product issue.

Is this stuff normally intended for going on as a surface on which to
tile etc? If so, presumably small craters wouldn't matter.

Maybe it's time to call it a day and consider something else.

I think that I may have mentioned that I used epoxy floor paint for
mine. I was mainly interested in a surface that was easy to clean
and wouldn't need to redone for a very long time. It has stood up
pretty well to machines (e.g. the one-tonne Felder) being rolled
across it.

I used the two stage product from Decorating Direct

http://www.decoratingdirect.co.uk/viewprod/t/TOREPXFP/

preceded by their sealer

http://www.decoratingdirect.co.uk/viewprod/t/TOREPXFPS/

This is something of a performance because of the minimum (16) and
maximum (48) hours recoating period. I had to plan out the whole
thing quite carefully, because I already had things in the workshop
that I couldn't rehome and obviously I couldn't leave them outside at
night, but I could fit everything into one half. This meant knocking
up some temporary dollies to move stuff easily and doing one half at
a time. Basically, what I did was:

Side 1 - sealer
wait 24hrs, move stuff across
Side 2 - sealer
wait 24hrs. move stuff across

repeat for first top coat
then on the final day, take everything out, very early in the
morning, and do second top coat all over.
Wait until very late and move everything back in.
Worked a treat.







--

..andy

RzB wrote in message
...
"Mark" wrote in message

Ok - I'm doing something wrong but what?
This is really frustrating and beginning to
tick me off.

Explain exactly how you are mixing this.

NB. The "lumps" in the picture are not
because the mixture has not been mixed
thoroughly. They are bubbles that have
not quite popped...

I have tried a number of methods...

I'm using a mixture of 3 parts water
to 1 part SBR. I mix this first in a number
of 4 pint plastic containers.

I then take a 25kg bag of the Leveling
Compound and put it into a large Trug...


So what make of SBR/compound are you using ?
With all the SBR admix I have used you are supposed to first lay a bonding
slurry, _no_ more then 2mm thick.
On top of this you would lay a sand/cement Screed with the appropriate
amount of sbr admix, it's always recommended that a concrete mixer or pan
type mixer is used for this,
paddle and hand mixing just don't work.

Ive never used a floor-levelling compound that can have a SBR admix added, I
missed that part in your original post.

one point worth noting is that with all plasters and semi liquid type
finishes you should _always_ slowly add the power to the water, not the
other way round as you are doing.


-

On Tue, 27 Dec 2005 18:30:43 -0000, RzB wrote:

Ok - I'm doing something wrong but what?
This is really frustrating and beginning to
tick me off.

I recently damp proofed an "old" section of
the garage that worked out really well - see....

www.gillandroy.com/diy/StoreroomFinished

However the floor was a bit of a problem.
All worked out well in the end but only after
some backbreaking hours.

I used a Cement Based Leveling Compound/SBR
mixture. Evidently the SBR makes the mixture
waterproof, more workable, flexible and stronger.
The problem I had was bubbles in the mixture when
laid. These popped and left craters in the finished
surface. I'm not talking about the odd one here and
there... It was literally covered! see...

www.gillandroy.com/diy/craters

This was put down to over entheusiastic mixing
with one of these...

http://www.screwfix.com/app/sfd/cat/...52400&ts=03505

I spent hours down on my knees filling each hole
by hand.

So when I came to next section I decided to mix by
hand. Small shovel in a builders tug...

Guess what - exacly the same - bubbles and craters. More
hours kneeling/filling... Hmmm...

More discussion with the vendor of the stuff..

Ok - do the mixing then let it settle in the tug for a while...
also buy a spiked roller from a builders merchant and use
that--- then you'll be ok...

Well none of the builders merchants had a clue about
a spiked roller... But I managed to buy one from here...

www.industrial-flooring.co.uk

See picture here...

www.gillandroy.com/diy/spiker

I have just done one further bag on the next section...
mixture left to settle, then pour, spread with trowel.
As bubbles start to appear splat them with the roller...
Great - but hang on.. they re-appear... In fact the roller
seem to have just about zero effect...

Is there an expert out there that can tell me what I'm
doing wrong!!!!!! Please!!!

Roy

Did you PVA seal the floor first?

Andy

Yes - the Epoxy paint will go on
after the Floor Leveling compound...

The storeroom

www.gillandroy.com/diy/StoreroomFinished

has leveling compound
then two coats of epoxy paint..

Roy

In article , group
says...
snip
I have tried a number of methods of mixing
the two together. My first efforts used a mixer
attached to a drill. I would add about 4 pints
of the liquid to the compound and stir till
all the liquid was taken up. Then add more
liquid and stir etc.. This was continued till
the mixture was smooth with no lumps.


You should be adding solid to liquid, not liquid to solid.

"Mark" wrote in message
...

snip

So what make of SBR/compound are you using ?
With all the SBR admix I have used you are supposed to first lay a bonding
slurry, _no_ more then 2mm thick.
On top of this you would lay a sand/cement Screed with the appropriate
amount of sbr admix, it's always recommended that a concrete mixer or pan
type mixer is used for this,
paddle and hand mixing just don't work.

Ive never used a floor-levelling compound that can have a SBR admix added,
I
missed that part in your original post.

one point worth noting is that with all plasters and semi liquid type
finishes you should _always_ slowly add the power to the water, not the
other way round as you are doing.


Hmmm - that's very interesting. I have re-read
the instructions...

It does indeed say add the powder to the liquid.
See the instructions... SLC.jpg...

http://www.gillandroy.com/diy/craters

Can this possibly be my problem? Does it really
make that much difference? I guess there is one
way to find out!...

The instructions say add 25Kg to 5L of liquid.
However I have found that the 5L is not enough
to get a pourable consistancy. More like 6.

I'll do a test section later this afternoon.....

So you would put "all" the liquid in the trug and then
slowly mix in the powder? Yes?

The paddle method and indeed the materials were
recommended by the manufacturer after a site visit.
The mfg saw this job as having very low technical
demands in comparrison to the industrial jobs they
normally handle. Overall they have been very helpful
and I'm very pleased with the initial room I did with
their products - apart from having to fill the bubbles!!!!

Many thanks for your help.
Roy

Did you PVA seal the floor first?

In one section yes, another section no....
Same result...

Thanks,
Roy

On Wed, 28 Dec 2005 15:02:25 -0000, "RzB"
wrote:


Did you PVA seal the floor first?

In one section yes, another section no....
Same result...


This really only leaves release of air or other gas as a result of the
air being trapped during mixing or other gas being produced from
chemical reaction......


--

..andy

RzB wrote in message
...
snip


Ive never used a floor-levelling compound that can have a SBR admix
added,
I
missed that part in your original post.

one point worth noting is that with all plasters and semi liquid type
finishes you should _always_ slowly add the power to the water, not the
other way round as you are doing.


Hmmm - that's very interesting. I have re-read
the instructions...

It does indeed say add the powder to the liquid.
See the instructions... SLC.jpg...

http://www.gillandroy.com/diy/craters

Can this possibly be my problem? Does it really
make that much difference? I guess there is one
way to find out!...

The instructions say add 25Kg to 5L of liquid.
However I have found that the 5L is not enough
to get a pourable consistancy. More like 6.

I'll do a test section later this afternoon.....

So you would put "all" the liquid in the trug and then
slowly mix in the powder? Yes?

Yes absolutely.
If it were me, I would first do a small test without the admix, if this
works ok do another With the admix.
When you are mixing a large volume it helps if you can have one person using
the mixing drill and another poring in the power, slowly add more power to
keeping the mix liquid at all times without lumps forming.

My mixing paddle runs at about 500rpm any faster then this you risk inducing
air into the mix.

Id be interested to know how it goes, as I still think you were mixing at
too high speed and also had lumps in the mix.


-

RzB wrote in message
...

Did you PVA seal the floor first?

In one section yes, another section no....
Same result...


Its does say on the instructions
http://pix.gillandroy.com/diy/craters/+SLC.jpg
dry or porous surfaces should be primed with pva/acrylic primer.



-

"Mark" wrote in message
...

RzB wrote in message
...

snip


I'll do a test section later this afternoon.....

So you would put "all" the liquid in the trug and then
slowly mix in the powder? Yes?

Yes absolutely.
If it were me, I would first do a small test without the admix, if this
works ok do another With the admix.
When you are mixing a large volume it helps if you can have one person
using
the mixing drill and another poring in the power, slowly add more power to
keeping the mix liquid at all times without lumps forming.

My mixing paddle runs at about 500rpm any faster then this you risk
inducing
air into the mix.

Id be interested to know how it goes, as I still think you were mixing at
too high speed and also had lumps in the mix.


Hmmm - I really don't think it was the speed, as I got
exactly the same effect when I mixed very carefully
with a small shovel.. I have been using one of these...

http://www.toolshopdirect.co.uk/shopscr2944.html

which has a top speed of 650 rpm. I have been running
it well down from top speed.

And - no lumps - honest :-)

As you suggest - I'm going to mix half a bag with just
water to see how that goes... Using your recommended
method..

Then do the same but with the SBR mix.

It will have to be later this afternoon as the "labourer"
is working till 4:30... Pah - "working" in a charity shop
- like putting a dog in a butchers shop :-)

I'll feed back as soon as I have done the tests..

Many thanks,
Roy

"Mark" wrote in message
...

RzB wrote in message
...

Did you PVA seal the floor first?

In one section yes, another section no....
Same result...


Its does say on the instructions
http://pix.gillandroy.com/diy/craters/+SLC.jpg
dry or porous surfaces should be primed with pva/acrylic primer.


Mark,

Yes - this was discussed with the manufacturer
who saw the floor and said it was not necessary
to do that. They put that in there for floors that
are very porous and in a bad way. That is not the
case in this instance.

Also when I did use PVA primer on one section
it made no difference to the bubbles... See response
to Andy Hall a little earlier in this thread...

Many thanks,
Roy

"Andy Hall" wrote in message
...

clip

This really only leaves release of air or other gas as a result of the
air being trapped during mixing or other gas being produced from
chemical reaction......

.andy


Yes - I think so. Mark in earlier response has pointed out
that my mixing method is wrong. So I'm going to give that a
try. Also with/without the SBR - that should clear up
the interraction possibility. We shall see...

Thanks,
Roy

RzB wrote:
Did you PVA seal the floor first?


In one section yes, another section no....
Same result...

Thanks,
Roy



Having used this type of screed a couple of times (from Builder Center),
I'd say the product you have is faulty.
Essentially it's some kind of inert mineral (not cement) mixed with an
SBR emulsion, except it doesn't actually "mix", but settles out after a
few minutes without stirring. The emulsion dries and binds the
aggregate. No curing or chemical reaction involved so no reason for air
to be finding its way to the surface.
I imagine the raised edges of the craters would be more of a problem
than the dips themselves.