Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

On 25/01/17 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Do what I did.
Buy a spirit level, some string and an awful lot of quick setting tile
cement.

And roughly fill in the worst bits with scrap cement and tiles left over
from the process as its cheaper to use broken tile and cement to fill
that 18mm gap, than straight cement.


--
€œit should be clear by now to everyone that activist environmentalism
(or environmental activism) is becoming a general ideology about humans,
about their freedom, about the relationship between the individual and
the state, and about the manipulation of people under the guise of a
'noble' idea. It is not an honest pursuit of 'sustainable development,'
a matter of elementary environmental protection, or a search for
rational mechanisms designed to achieve a healthy environment. Yet
things do occur that make you shake your head and remind yourself that
you live neither in Joseph Stalins Communist era, nor in the Orwellian
utopia of 1984.€�

Vaclav Klaus

"The Natural Philosopher" wrote in message
news
On 25/01/17 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Do what I did.
Buy a spirit level, some string and an awful lot of quick setting tile
cement.

And roughly fill in the worst bits with scrap cement and tiles left over
from the process as its cheaper to use broken tile and cement to fill that
18mm gap, than straight cement.

Seems to me that's a cowboy job. Then again, if it does the job, I suppose.

On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex cement on
the top.


--
Cheers,

John.

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

I'd say as a first thought, bloody hell, that kind of removal is going to
create the mother of all dust problems for years, no matter how careful you
are. How did it get to be like this?
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Grumps" wrote in message
news
Hi All
I have a concrete kitchen floor that is not level enough for my liking. I
am about to lay ceramic tiles. It is basically a valley. The high points
are along opposite walls, and the low point is 18mm down and about 2.5m
from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that needs
to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

On 26/01/2017 07:10, Brian Gaff wrote:
I'd say as a first thought, bloody hell, that kind of removal is going to
create the mother of all dust problems for years, no matter how careful you
are. How did it get to be like this?
Brian

There would be lots of dust if I went this route, that's for sure.

I think the house was probably built like that. There are no signs of
cracks in the floor, although there was subsidence 20+ years ago (that
was remedied).

On 26/01/2017 00:57, John Rumm wrote:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex cement on
the top.

Not a bad idea. 3:1 sand cement mix?

On 26/01/17 00:57, John Rumm wrote:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex cement on
the top.



+1

I would use an SBR regime too - SBR added to the mixing water for the
screed, and paint the existing floor with SBR where the extra screed
will go.

You can take it down to 10mm without fear of the new screed crumbling
and it will bond like iron to the old stuff. Also tile cement loves SBR
treated surfaces.

On 26/01/17 08:22, Grumps wrote:
On 26/01/2017 00:57, John Rumm wrote:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex cement on
the top.

Not a bad idea. 3:1 sand cement mix?


No - like this:

http://www.everbuild.co.uk/image/dat...SBR%20Bond.doc

On 25/01/2017 23:31, The Natural Philosopher wrote:
On 25/01/17 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Do what I did.
Buy a spirit level, some string and an awful lot of quick setting tile
cement.

And roughly fill in the worst bits with scrap cement and tiles left over
from the process as its cheaper to use broken tile and cement to fill
that 18mm gap, than straight cement.

Thanks. That'd work.
Or a sand cement screed as John suggested.

On 26/01/17 08:14, Grumps wrote:
On 26/01/2017 07:10, Brian Gaff wrote:
I'd say as a first thought, bloody hell, that kind of removal is going tosten
create the mother of all dust problems for years, no matter how
careful you
are. How did it get to be like this?
Brian

There would be lots of dust if I went this route, that's for sure.

I think the house was probably built like that. There are no signs of
cracks in the floor, although there was subsidence 20+ years ago (that
was remedied).



I had the same problem - I took a tungsten flail floor grinder (looks
like a cylinder lawn mower) to the floor first. The house wasa building
site and empty.

I taped the room's doors shut.

Dust got everywhere and we were sweeping it up by the bucket load.

On 26/01/2017 08:25, Tim Watts wrote:
On 26/01/17 00:57, John Rumm wrote:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex cement on
the top.



+1

I would use an SBR regime too - SBR added to the mixing water for the
screed, and paint the existing floor with SBR where the extra screed
will go.

You can take it down to 10mm without fear of the new screed crumbling
and it will bond like iron to the old stuff. Also tile cement loves SBR
treated surfaces.

Ta.
When you say "you can take it down to 10mm" do you mean that's the
thinnest the screed can be?

On 25/01/17 23:36, bm wrote:
"The Natural Philosopher" wrote in message
news
On 25/01/17 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Do what I did.
Buy a spirit level, some string and an awful lot of quick setting tile
cement.

And roughly fill in the worst bits with scrap cement and tiles left over
from the process as its cheaper to use broken tile and cement to fill that
18mm gap, than straight cement.

Seems to me that's a cowboy job. Then again, if it does the job, I suppose.



It's not a cowboy job any more than filling it up with cement and sand
or levelling compound would be.

The cowboy job was the 'professional' screeders who failed to stop it
slumping.

It's lasted 14 years to date with no problems



--
"Anyone who believes that the laws of physics are mere social
conventions is invited to try transgressing those conventions from the
windows of my apartment. (I live on the twenty-first floor.) "

Alan Sokal

On 26/01/2017 08:22, Grumps wrote:
On 26/01/2017 00:57, John Rumm wrote:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex cement on
the top.

Not a bad idea. 3:1 sand cement mix?

Yup, (possibly with plasters or silver sand - dpending on how thin you
want to feather it), and use a good admixture (SBR being idea as Tim
suggests)


--
Cheers,

John.

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

On 26/01/2017 08:37, Grumps wrote:
On 26/01/2017 08:25, Tim Watts wrote:
On 26/01/17 00:57, John Rumm wrote:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the
room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along
the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small
area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex cement on
the top.



+1

I would use an SBR regime too - SBR added to the mixing water for the
screed, and paint the existing floor with SBR where the extra screed
will go.

You can take it down to 10mm without fear of the new screed crumbling
and it will bond like iron to the old stuff. Also tile cement loves SBR
treated surfaces.

Ta.
When you say "you can take it down to 10mm" do you mean that's the
thinnest the screed can be?

Yup, sand and cement screeds can normally only go so thin (else the
edges crack away when walked on). However you may be able to go a bit
under that for something that will be re-screeded in latex since that
will protect the edges.

So basically fill all the big holes with sand and cement (+SBR), then
cover everything with the levelling compound.


--
Cheers,

John.

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

On 26/01/17 08:37, Grumps wrote:
On 26/01/2017 08:25, Tim Watts wrote:

You can take it down to 10mm without fear of the new screed crumbling
and it will bond like iron to the old stuff. Also tile cement loves SBR
treated surfaces.

Ta.
When you say "you can take it down to 10mm" do you mean that's the
thinnest the screed can be?


Yes.

And you won't do that with regular screed - not without it crumbling.

On 26/01/17 09:21, John Rumm wrote:

So basically fill all the big holes with sand and cement (+SBR), then
cover everything with the levelling compound.



That's what I did

On 26/01/2017 09:21, John Rumm wrote:
On 26/01/2017 08:37, Grumps wrote:
On 26/01/2017 08:25, Tim Watts wrote:
On 26/01/17 00:57, John Rumm wrote:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my
liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the
room).
If I use self levelling compound then I'm going to need 8-10 20kg
bags.
But, if I manage to reduce the level of just a one metre strip along
the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small
area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent
face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement
screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex
cement on
the top.



+1

I would use an SBR regime too - SBR added to the mixing water for the
screed, and paint the existing floor with SBR where the extra screed
will go.

You can take it down to 10mm without fear of the new screed crumbling
and it will bond like iron to the old stuff. Also tile cement loves SBR
treated surfaces.

Ta.
When you say "you can take it down to 10mm" do you mean that's the
thinnest the screed can be?

Yup, sand and cement screeds can normally only go so thin (else the
edges crack away when walked on). However you may be able to go a bit
under that for something that will be re-screeded in latex since that
will protect the edges.

So basically fill all the big holes with sand and cement (+SBR), then
cover everything with the levelling compound.

So, using SBR and Tim's linked doc, the ratio is 3.5:1 plus some SBR.
How much sand and cement (in bags) would 1m3 be (not that I need that
amount)?

On 26/01/17 09:18, John Rumm wrote:
On 26/01/2017 08:22, Grumps wrote:
On 26/01/2017 00:57, John Rumm wrote:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the
room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along
the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small
area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex cement on
the top.

Not a bad idea. 3:1 sand cement mix?

Yup, (possibly with plasters or silver sand - dpending on how thin you
want to feather it), and use a good admixture (SBR being idea as Tim
suggests)


sand + cement alone will crack and lift sub around 20mm

You need sonmethi8ng designed to stay together in thin layers, like
levelling compound or - gasp - tile cement.


--
No Apple devices were knowingly used in the preparation of this post.

On 26/01/2017 09:57, Grumps wrote:
On 26/01/2017 09:21, John Rumm wrote:
On 26/01/2017 08:37, Grumps wrote:
On 26/01/2017 08:25, Tim Watts wrote:
On 26/01/17 00:57, John Rumm wrote:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my
liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the
room).
If I use self levelling compound then I'm going to need 8-10 20kg
bags.
But, if I manage to reduce the level of just a one metre strip along
the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small
area
by cutting lots of slices and then chiselling the bits out. But do
you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent
face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement
screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex
cement on
the top.



+1

I would use an SBR regime too - SBR added to the mixing water for the
screed, and paint the existing floor with SBR where the extra screed
will go.

You can take it down to 10mm without fear of the new screed crumbling
and it will bond like iron to the old stuff. Also tile cement loves SBR
treated surfaces.

Ta.
When you say "you can take it down to 10mm" do you mean that's the
thinnest the screed can be?

Yup, sand and cement screeds can normally only go so thin (else the
edges crack away when walked on). However you may be able to go a bit
under that for something that will be re-screeded in latex since that
will protect the edges.

So basically fill all the big holes with sand and cement (+SBR), then
cover everything with the levelling compound.

So, using SBR and Tim's linked doc, the ratio is 3.5:1 plus some SBR.
How much sand and cement (in bags) would 1m3 be (not that I need that
amount)?

One of these will probably do you:

http://www.pavingexpert.com/calcall.htm#focus02

While you are at it, you may find:

http://www.pavingexpert.com/sbr_01.htm

handy...




--
Cheers,

John.

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On 26/01/2017 08:26, Tim Watts wrote:
On 26/01/17 08:22, Grumps wrote:
On 26/01/2017 00:57, John Rumm wrote:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the
room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along
the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small
area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex cement on
the top.

Not a bad idea. 3:1 sand cement mix?


No - like this:

http://www.everbuild.co.uk/image/dat...SBR%20Bond.doc

That doc says mix using a forced action mixer. How important is this,
compared to using a £10/day standard mixer?

On 26/01/17 10:50, Grumps wrote:

That doc says mix using a forced action mixer. How important is this,
compared to using a £10/day standard mixer?


It's not - a regular cement mixer works just fine. I worked to a
different document (Cementone IIRC) which did not mention forced mixing.

You could even mix by hand, but mix well and keep the water down as teh
SBR acts as a plasticiser so you need less water than expected.

The important thing is to soak the area in 1:1 diluted SBR first and
allow to dry, then paint on an SBR/water/pure cement slurry *just*
before you apply the screed. This is the primer they refer to (the
Cementone document went into more depth).

The end result IME is that the screed is bonded to the top 10-20mm of
the substrate.

Don't have high spots as I did in one area, about 10sq inches. It took
30 minutes with an SDS and a scutch comb chisel to cut it back - it
really was like iron.

Also - wear gloves and take heed of the cleaning your tools bit in the
doc This stuff will bond to stainless steel forever - I still have a
mixing bowl that has slurry on it.

John Rumm Wrote in message:
On 26/01/2017 08:37, Grumps wrote:
On 26/01/2017 08:25, Tim Watts wrote:
On 26/01/17 00:57, John Rumm wrote:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the
room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along
the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small
area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex cement on
the top.



+1

I would use an SBR regime too - SBR added to the mixing water for the
screed, and paint the existing floor with SBR where the extra screed
will go.

You can take it down to 10mm without fear of the new screed crumbling
and it will bond like iron to the old stuff. Also tile cement loves SBR
treated surfaces.

Ta.
When you say "you can take it down to 10mm" do you mean that's the
thinnest the screed can be?

Yup, sand and cement screeds can normally only go so thin (else the
edges crack away when walked on). However you may be able to go a bit
under that for something that will be re-screeded in latex since that
will protect the edges.

So basically fill all the big holes with sand and cement (+SBR), then
cover everything with the levelling compound.

Though given the OP's tiling, couldn't he use some of that
levelling compound budget on an extra bag(s) of tile adhesive
&
make up the 9mm to 0mm bits with that?
--
Jim K


----Android NewsGroup Reader----
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On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.


If you really want to lower it - rent a scrabbler for 1/2 a day

On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.


or pour some self levelling screed in the low parts .. so what you have
to make good with tile adhesive is not excessive.

rick Wrote in message:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the room).
If I use self levelling compound then I'm going to need 8-10 20kg bags.
But, if I manage to reduce the level of just a one metre strip along the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.


If you really want to lower it - rent a scrabbler for 1/2 a day


He has a depression in the middle as I read it....
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On 26/01/2017 10:24, The Natural Philosopher wrote:
On 26/01/17 09:18, John Rumm wrote:
On 26/01/2017 08:22, Grumps wrote:
On 26/01/2017 00:57, John Rumm wrote:
On 25/01/2017 23:21, Grumps wrote:
Hi All
I have a concrete kitchen floor that is not level enough for my
liking.
I am about to lay ceramic tiles. It is basically a valley. The high
points are along opposite walls, and the low point is 18mm down and
about 2.5m from the highest point (roughly 2/3 the way across the
room).
If I use self levelling compound then I'm going to need 8-10 20kg
bags.
But, if I manage to reduce the level of just a one metre strip along
the
high-point wall by 12mm, then all I'll need is 2-3 bags.
I have my trusty little angle grinder that I've slowly done a small
area
by cutting lots of slices and then chiselling the bits out. But do you
reckon a grinding cup wheel would be a better/quicker solution?
The room is sealed from the rest of the house, and I have a decent
face
mask. I've made a quick calculation and the amount of concrete that
needs to be removed is about 2/3 cubic foot.
Ta for any comments or alternative suggestions.

Sounds like a hard way to do it. I would use a sand and cement
screed to
half fill the deepest "holes", say bringing them up to only 5mm below
level, and then slap half a dozen bags of self levelling latex
cement on
the top.

Not a bad idea. 3:1 sand cement mix?

Yup, (possibly with plasters or silver sand - dpending on how thin you
want to feather it), and use a good admixture (SBR being idea as Tim
suggests)


sand + cement alone will crack and lift sub around 20mm

You need sonmethi8ng designed to stay together in thin layers, like
levelling compound or - gasp - tile cement.

With SBR it will stay together at 10mm IME. However we are talking more
than that by the time the self levelling is over the top.


--
Cheers,

John.

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