Pulled up some old self adhesive vinyl tiles in a porch today, thin layer of
self levelling compound came up with them, leaving a sub floor of really
friable concrete screed. Could be crumbled in your fingers.

Tried PVA, helped a little but I conclude that whoever laid the screed
didn't use the right mix in the first place.

No point trying to lay anything on top of the screed, so any alternatives to
digging it all out & starting again?

More PVA, different mix (I used 5-1)?



--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

In article ,
"The Medway Handyman" writes:
Pulled up some old self adhesive vinyl tiles in a porch today, thin layer of
self levelling compound came up with them, leaving a sub floor of really
friable concrete screed. Could be crumbled in your fingers.

Tried PVA, helped a little but I conclude that whoever laid the screed
didn't use the right mix in the first place.

No point trying to lay anything on top of the screed, so any alternatives to
digging it all out & starting again?

More PVA, different mix (I used 5-1)?

Sounds OK.
It must actually soak in -- is the floor sufficiently porous?
Did you leave it to fully dry? (Possibly hard to tell if it
soaked in - might need to check a day later. Soaked-in isn't
the same as dried.)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

The Medway Handyman wrote:
Pulled up some old self adhesive vinyl tiles in a porch today, thin layer of
self levelling compound came up with them, leaving a sub floor of really
friable concrete screed. Could be crumbled in your fingers.

Tried PVA, helped a little but I conclude that whoever laid the screed
didn't use the right mix in the first place.

No point trying to lay anything on top of the screed, so any alternatives to
digging it all out & starting again?

More PVA, different mix (I used 5-1)?


About a gallon of diluted PVA.

Let it soak right in.

On Thu, 23 Apr 2009 17:10:55 GMT, "The Medway Handyman"
had this to say:

Pulled up some old self adhesive vinyl tiles in a porch today, thin layer of
self levelling compound came up with them, leaving a sub floor of really
friable concrete screed. Could be crumbled in your fingers.

Tried PVA, helped a little but I conclude that whoever laid the screed
didn't use the right mix in the first place.

No point trying to lay anything on top of the screed, so any alternatives to
digging it all out & starting again?

Angle grinder.

HTH -

--
Frank Erskine

Andrew Gabriel wrote:
In article ,
"The Medway Handyman" writes:
Pulled up some old self adhesive vinyl tiles in a porch today, thin
layer of self levelling compound came up with them, leaving a sub
floor of really friable concrete screed. Could be crumbled in your
fingers.

Tried PVA, helped a little but I conclude that whoever laid the
screed didn't use the right mix in the first place.

No point trying to lay anything on top of the screed, so any
alternatives to digging it all out & starting again?

More PVA, different mix (I used 5-1)?

Sounds OK.
It must actually soak in -- is the floor sufficiently porous?

Like a sponge.

Did you leave it to fully dry? (Possibly hard to tell if it
soaked in - might need to check a day later. Soaked-in isn't
the same as dried.)

Ah. Left it for about 2 hours, maybe it had just soaked in.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Medway Handyman wrote:
Andrew Gabriel wrote:
In article ,
"The Medway Handyman" writes:
Pulled up some old self adhesive vinyl tiles in a porch today, thin
layer of self levelling compound came up with them, leaving a sub
floor of really friable concrete screed. Could be crumbled in your
fingers.

Tried PVA, helped a little but I conclude that whoever laid the
screed didn't use the right mix in the first place.

No point trying to lay anything on top of the screed, so any
alternatives to digging it all out & starting again?

More PVA, different mix (I used 5-1)?
Sounds OK.
It must actually soak in -- is the floor sufficiently porous?

Like a sponge.

Did you leave it to fully dry? (Possibly hard to tell if it
soaked in - might need to check a day later. Soaked-in isn't
the same as dried.)

Ah. Left it for about 2 hours, maybe it had just soaked in.


pour until no more will go in, and leave a week.,

The Natural Philosopher wrote:
The Medway Handyman wrote:
Andrew Gabriel wrote:
In article ,
"The Medway Handyman" writes:
Pulled up some old self adhesive vinyl tiles in a porch today, thin
layer of self levelling compound came up with them, leaving a sub
floor of really friable concrete screed. Could be crumbled in your
fingers.

Tried PVA, helped a little but I conclude that whoever laid the
screed didn't use the right mix in the first place.

No point trying to lay anything on top of the screed, so any
alternatives to digging it all out & starting again?

More PVA, different mix (I used 5-1)?
Sounds OK.
It must actually soak in -- is the floor sufficiently porous?

Like a sponge.

Did you leave it to fully dry? (Possibly hard to tell if it
soaked in - might need to check a day later. Soaked-in isn't
the same as dried.)

Ah. Left it for about 2 hours, maybe it had just soaked in.


pour until no more will go in, and leave a week.,

I'd use cement slurry with pva in it as well. The cement is
waterproof, pva isnt. Its also stronger.


NT

wrote:
The Natural Philosopher wrote:
The Medway Handyman wrote:
Andrew Gabriel wrote:
In article ,
"The Medway Handyman" writes:
Pulled up some old self adhesive vinyl tiles in a porch today,
thin layer of self levelling compound came up with them, leaving
a sub floor of really friable concrete screed. Could be crumbled
in your fingers.

Tried PVA, helped a little but I conclude that whoever laid the
screed didn't use the right mix in the first place.

No point trying to lay anything on top of the screed, so any
alternatives to digging it all out & starting again?

More PVA, different mix (I used 5-1)?
Sounds OK.
It must actually soak in -- is the floor sufficiently porous?

Like a sponge.

Did you leave it to fully dry? (Possibly hard to tell if it
soaked in - might need to check a day later. Soaked-in isn't
the same as dried.)

Ah. Left it for about 2 hours, maybe it had just soaked in.


pour until no more will go in, and leave a week.,

I'd use cement slurry with pva in it as well. The cement is
waterproof, pva isnt. Its also stronger.

Cement or mortar slurry?


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Medway Handyman wrote:

Cement or mortar slurry?

Cement - its works as a tanking solution when mixed with PVA in some
cases IIUC.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm coughed up some electrons that declared:

The Medway Handyman wrote:

Cement or mortar slurry?

Cement - its works as a tanking solution when mixed with PVA in some
cases IIUC.


Think I'll try that on some loose patches on my floor (some bits seem as
described here - 99% sand 1% cement).

In article ,
Tim S writes:
John Rumm coughed up some electrons that declared:

The Medway Handyman wrote:

Cement or mortar slurry?

Cement - its works as a tanking solution when mixed with PVA in some
cases IIUC.


Think I'll try that on some loose patches on my floor (some bits seem as
described here - 99% sand 1% cement).

If the floor is damp and needs tanking, use EVA rather than PVA
in the slurry. (It's usually sold as Exterior PVA.)
SBR is another choice, or a proprietry tanking cement.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andrew Gabriel coughed up some electrons that declared:

In article ,
Tim S writes:
John Rumm coughed up some electrons that declared:

The Medway Handyman wrote:

Cement or mortar slurry?

Cement - its works as a tanking solution when mixed with PVA in some
cases IIUC.


Think I'll try that on some loose patches on my floor (some bits seem as
described here - 99% sand 1% cement).

If the floor is damp and needs tanking, use EVA rather than PVA
in the slurry. (It's usually sold as Exterior PVA.)

Of course - I know EVA as a woodglue. Never thought of it in the same
general purpose light as PVA


SBR is another choice, or a proprietry tanking cement.


I'll look up that tanking cement - sounds interesting - ta

Tim S wrote:
John Rumm coughed up some electrons that declared:

The Medway Handyman wrote:

Cement or mortar slurry?

Cement - its works as a tanking solution when mixed with PVA in some
cases IIUC.


Think I'll try that on some loose patches on my floor (some bits seem
as described here - 99% sand 1% cement).

No sign of damp, but I reckon the same bloke mixed it.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Medway Handyman wrote:
wrote:
The Natural Philosopher wrote:
The Medway Handyman wrote:
Andrew Gabriel wrote:
In article ,
"The Medway Handyman" writes:
Pulled up some old self adhesive vinyl tiles in a porch today,
thin layer of self levelling compound came up with them, leaving
a sub floor of really friable concrete screed. Could be crumbled
in your fingers.

Tried PVA, helped a little but I conclude that whoever laid the
screed didn't use the right mix in the first place.

No point trying to lay anything on top of the screed, so any
alternatives to digging it all out & starting again?

More PVA, different mix (I used 5-1)?
Sounds OK.
It must actually soak in -- is the floor sufficiently porous?

Like a sponge.

Did you leave it to fully dry? (Possibly hard to tell if it
soaked in - might need to check a day later. Soaked-in isn't
the same as dried.)

Ah. Left it for about 2 hours, maybe it had just soaked in.


pour until no more will go in, and leave a week.,

I'd use cement slurry with pva in it as well. The cement is
waterproof, pva isnt. Its also stronger.

Cement or mortar slurry?

just cement & water. On 2nd thoughts I'd maybe leave out the pva
altogether, it will only thicken the mix up and retard the cement
penetration, and cement does a far better job of cnsolidating a floor
than pva ever will.


NT

The Medway Handyman wrote:
wrote:
The Natural Philosopher wrote:
The Medway Handyman wrote:
Andrew Gabriel wrote:
In article ,
"The Medway Handyman" writes:
Pulled up some old self adhesive vinyl tiles in a porch today,
thin layer of self levelling compound came up with them, leaving
a sub floor of really friable concrete screed. Could be crumbled
in your fingers.

Tried PVA, helped a little but I conclude that whoever laid the
screed didn't use the right mix in the first place.

No point trying to lay anything on top of the screed, so any
alternatives to digging it all out & starting again?

More PVA, different mix (I used 5-1)?
Sounds OK.
It must actually soak in -- is the floor sufficiently porous?

Like a sponge.

Did you leave it to fully dry? (Possibly hard to tell if it
soaked in - might need to check a day later. Soaked-in isn't
the same as dried.)

Ah. Left it for about 2 hours, maybe it had just soaked in.


pour until no more will go in, and leave a week.,

I'd use cement slurry with pva in it as well. The cement is
waterproof, pva isnt. Its also stronger.

Cement or mortar slurry?

just cement & water. On 2nd thoughts I'd maybe leave out the pva
altogether, it will only thicken the mix up and retard the cement
penetration, and cement does a far better job of cnsolidating a floor
than pva ever will.


NT

The Medway Handyman wrote:
Tim S wrote:
John Rumm coughed up some electrons that declared:

The Medway Handyman wrote:

Cement or mortar slurry?

Cement - its works as a tanking solution when mixed with PVA in some
cases IIUC.


Think I'll try that on some loose patches on my floor (some bits seem
as described here - 99% sand 1% cement).

No sign of damp, but I reckon the same bloke mixed it.


Maybe someone could advise me here... I want to make a very weak
mortar mix, bare minimum cement content, to make blocks that will be
cast in plastic containers, and stay in them forever more. They'll
only ever see trivial loads, theyre just static weights effectively.
It doesnt matter a monkeys if they crack into 8 pieces, the only
requirement is they dont disintegrate so badly that they empty
themselves out through 5mm holes. How weak a mix can I go? 12:1?


NT

wrote:
The Medway Handyman wrote:
wrote:
The Natural Philosopher wrote:
The Medway Handyman wrote:
Andrew Gabriel wrote:
In article ,
"The Medway Handyman" writes:
Pulled up some old self adhesive vinyl tiles in a porch today,
thin layer of self levelling compound came up with them, leaving
a sub floor of really friable concrete screed. Could be crumbled
in your fingers.

Tried PVA, helped a little but I conclude that whoever laid the
screed didn't use the right mix in the first place.

No point trying to lay anything on top of the screed, so any
alternatives to digging it all out & starting again?

More PVA, different mix (I used 5-1)?
Sounds OK.
It must actually soak in -- is the floor sufficiently porous?
Like a sponge.

Did you leave it to fully dry? (Possibly hard to tell if it
soaked in - might need to check a day later. Soaked-in isn't
the same as dried.)
Ah. Left it for about 2 hours, maybe it had just soaked in.


pour until no more will go in, and leave a week.,
I'd use cement slurry with pva in it as well. The cement is
waterproof, pva isnt. Its also stronger.
Cement or mortar slurry?

just cement & water. On 2nd thoughts I'd maybe leave out the pva
altogether, it will only thicken the mix up and retard the cement
penetration, and cement does a far better job of cnsolidating a floor
than pva ever will.


NT

You're kidding of course. Have you ever tried it?
There's a good reason why these additives are so widely used. No floor
covering manufacturer will guarantee their products without proper
screeding.

wrote:
The Medway Handyman wrote:
Tim S wrote:
John Rumm coughed up some electrons that declared:

The Medway Handyman wrote:

Cement or mortar slurry?
Cement - its works as a tanking solution when mixed with PVA in some
cases IIUC.

Think I'll try that on some loose patches on my floor (some bits seem
as described here - 99% sand 1% cement).
No sign of damp, but I reckon the same bloke mixed it.


Maybe someone could advise me here... I want to make a very weak
mortar mix, bare minimum cement content, to make blocks that will be
cast in plastic containers, and stay in them forever more. They'll
only ever see trivial loads, theyre just static weights effectively.
It doesnt matter a monkeys if they crack into 8 pieces, the only
requirement is they dont disintegrate so badly that they empty
themselves out through 5mm holes. How weak a mix can I go? 12:1?

Probably... they say 10:1 is enough to stop the sand migrating under the
influence of water under paths etc, so since yours won't be getting wet,
a tad weaker would not hurt. (then again the difference in cost of
materials between 12:1 and 10:1 is going to be next to nothing)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/