I seem to have a natural knack for plastering. Not sure where it comes
from, but without wishing to blow my own trumpet, I can achieve a
'perfect finish' freehand with little effort. So when I came to having to
rendering a square meter of inside wall, I approached the task with
supreme confidence bordering on contempt.
What a mistake that was! Unlike plaster, render seems to have an
irresistible affinity with the floor - which is where nearly all of it
ended up. To add insult to injury, when I was carrying out final
smoothing on what modest proportion I had managed to apply, a large patch
in the middle simply fell out!
Conclusion: use plaster for walls and render for floors and if you need
an outside wall rendered, get a proper tradesman in.
Anyone else had nightmares rendering?

"Cursitor Doom" wrote in message
...
I seem to have a natural knack for plastering. Not sure where it comes
from, but without wishing to blow my own trumpet, I can achieve a
'perfect finish' freehand with little effort. So when I came to having to
rendering a square meter of inside wall, I approached the task with
supreme confidence bordering on contempt.
What a mistake that was! Unlike plaster, render seems to have an
irresistible affinity with the floor - which is where nearly all of it
ended up. To add insult to injury, when I was carrying out final
smoothing on what modest proportion I had managed to apply, a large patch
in the middle simply fell out!
Conclusion: use plaster for walls and render for floors and if you need
an outside wall rendered, get a proper tradesman in.
Anyone else had nightmares rendering?

The wall was probably too dry. Or dusty.
Sucks the water out and the render falls off.
Wet the wall down before you start.
To make it really strong or if the surface is crumbly, prime with diluted
PVA a few times & mix the render up with the same.
(Follow instructions on the PVA container.)

On 18/11/14 17:36, Cursitor Doom wrote:
I seem to have a natural knack for plastering. Not sure where it comes
from, but without wishing to blow my own trumpet, I can achieve a
'perfect finish' freehand with little effort. So when I came to having to
rendering a square meter of inside wall, I approached the task with
supreme confidence bordering on contempt.
What a mistake that was! Unlike plaster, render seems to have an
irresistible affinity with the floor - which is where nearly all of it
ended up. To add insult to injury, when I was carrying out final
smoothing on what modest proportion I had managed to apply, a large patch
in the middle simply fell out!
Conclusion: use plaster for walls and render for floors and if you need
an outside wall rendered, get a proper tradesman in.
Anyone else had nightmares rendering?


I rendered the inside of a fireplace to take a stove.

It did have a tendency to slump - luckily I have not made it too wet or
I would have been in real trouble.

I think you need to keep it slightly towards the dry side of the mix
spectrum...

On Tue, 18 Nov 2014 17:50:34 +0000, harryagain wrote:

The wall was probably too dry. Or dusty.
Sucks the water out and the render falls off.
Wet the wall down before you start.
To make it really strong or if the surface is crumbly, prime with
diluted PVA a few times & mix the render up with the same.
(Follow instructions on the PVA container.)

I did prime it with dilute PVA, but just the once. Immediately prior to
applying the render I also re-wet it with a plain water spray. I'm
guessing it would have been *even* worse if I hadn't!

On 18/11/14 17:36, Cursitor Doom wrote:
I seem to have a natural knack for plastering. Not sure where it comes
from, but without wishing to blow my own trumpet, I can achieve a
'perfect finish' freehand with little effort. So when I came to having to
rendering a square meter of inside wall, I approached the task with
supreme confidence bordering on contempt.
What a mistake that was! Unlike plaster, render seems to have an
irresistible affinity with the floor - which is where nearly all of it
ended up. To add insult to injury, when I was carrying out final
smoothing on what modest proportion I had managed to apply, a large patch
in the middle simply fell out!
Conclusion: use plaster for walls and render for floors and if you need
an outside wall rendered, get a proper tradesman in.
Anyone else had nightmares rendering?

Ideally you need a gravity deflector from a tool hire shop. Position it
according to the instructions and you can have a localised gravity field
that makes the vertical wall effectively horizontal. You have to leave
it in place until the render has set, which is expensive because the
deflectors are usually rated at 4kW. Well worth it though. After the
render is hard you can have a bit of fun. Put the cat on the wall and it
will totally freak out!

http://www.northerntoolhire.com/prod...vity-Deflector



Bill

"Cursitor Doom" wrote in message
...
I seem to have a natural knack for plastering. Not sure where it comes
from, but without wishing to blow my own trumpet, I can achieve a
'perfect finish' freehand with little effort. So when I came to having to
rendering a square meter of inside wall, I approached the task with
supreme confidence bordering on contempt.
What a mistake that was! Unlike plaster, render seems to have an
irresistible affinity with the floor - which is where nearly all of it
ended up. To add insult to injury, when I was carrying out final
smoothing on what modest proportion I had managed to apply, a large patch
in the middle simply fell out!
Conclusion: use plaster for walls and render for floors and if you need
an outside wall rendered, get a proper tradesman in.
Anyone else had nightmares rendering?


Render is different from skimming in that it has practically zero adhesion
qualities.

It can be applied in 6mm coats, so if you've tried to do what everyone tries
to do the first time, IE fill up a half inch coat in one go, then the floor
is where most of it will go. The first coat needs to be criss-crossed so as
to give a key to the second coat.
The other drawback with trying to get too much on in one go is that it
slumps, often these get missed and the result is a concrete-like bulge that
is visible after plaster, wallpaper and several coats of emulsion.

Also, render doesn't get smoothed if it's inside, it needs to be skimmed, so
it should be roughed up prior to skimming, this is achieved by rubbing it
with a bit of wood with a few nails in it, usually in a circular motion to
leave grooves in which the skimming can adhere. This is carried out when
it's set but not dry, about 12 hours after application in a warmish house.

On Tue, 18 Nov 2014 21:06:19 +0000, Phil L wrote:

Render is different from skimming in that it has practically zero
adhesion qualities.

It can be applied in 6mm coats, so if you've tried to do what everyone
tries to do the first time, IE fill up a half inch coat in one go, then
the floor is where most of it will go. The first coat needs to be
criss-crossed so as to give a key to the second coat.
The other drawback with trying to get too much on in one go is that it
slumps, often these get missed and the result is a concrete-like bulge
that is visible after plaster, wallpaper and several coats of emulsion.

Thanks for the info, Phil. Well I've been under a misapprehension, then.
I always thought render was something you could trowel on as thick as you
please. Oh well, it's One Coat plaster for me in future!

Bill Wright wrote:

On 18/11/14 17:36, Cursitor Doom wrote:
I seem to have a natural knack for plastering. Not sure where it comes
from, but without wishing to blow my own trumpet, I can achieve a
'perfect finish' freehand with little effort. So when I came to
having to
rendering a square meter of inside wall, I approached the task with
supreme confidence bordering on contempt.
What a mistake that was! Unlike plaster, render seems to have an
irresistible affinity with the floor - which is where nearly all of it
ended up. To add insult to injury, when I was carrying out final
smoothing on what modest proportion I had managed to apply, a large
patch
in the middle simply fell out!
Conclusion: use plaster for walls and render for floors and if you need
an outside wall rendered, get a proper tradesman in.
Anyone else had nightmares rendering?

Ideally you need a gravity deflector from a tool hire shop. Position it
according to the instructions and you can have a localised gravity field
that makes the vertical wall effectively horizontal. You have to leave
it in place until the render has set, which is expensive because the
deflectors are usually rated at 4kW. Well worth it though. After the
render is hard you can have a bit of fun. Put the cat on the wall and it
will totally freak out!

http://www.northerntoolhire.com/prod...vity-Deflector



Bill
Link won't work.

On Wed, 19 Nov 2014 11:56:49 +1100
F Murtz wrote:

Bill Wright wrote:

On 18/11/14 17:36, Cursitor Doom wrote:
I seem to have a natural knack for plastering. Not sure where it
comes from, but without wishing to blow my own trumpet, I can
achieve a 'perfect finish' freehand with little effort. So when I
came to having to
rendering a square meter of inside wall, I approached the task
with supreme confidence bordering on contempt.
What a mistake that was! Unlike plaster, render seems to have an
irresistible affinity with the floor - which is where nearly all
of it ended up. To add insult to injury, when I was carrying out
final smoothing on what modest proportion I had managed to apply,
a large patch
in the middle simply fell out!
Conclusion: use plaster for walls and render for floors and if
you need an outside wall rendered, get a proper tradesman in.
Anyone else had nightmares rendering?

Ideally you need a gravity deflector from a tool hire shop.
Position it according to the instructions and you can have a
localised gravity field that makes the vertical wall effectively
horizontal. You have to leave it in place until the render has set,
which is expensive because the deflectors are usually rated at 4kW.
Well worth it though. After the render is hard you can have a bit
of fun. Put the cat on the wall and it will totally freak out!

http://www.northerntoolhire.com/prod...vity-Deflector



Bill
Link won't work.

It's probably somewhere near the Electric Sheep of North Wales.

--
Davey.

On Tuesday, November 18, 2014 11:10:31 PM UTC, Cursitor Doom wrote:
On Tue, 18 Nov 2014 21:06:19 +0000, Phil L wrote:

Render is different from skimming in that it has practically zero
adhesion qualities.

It can be applied in 6mm coats, so if you've tried to do what everyone
tries to do the first time, IE fill up a half inch coat in one go, then
the floor is where most of it will go. The first coat needs to be
criss-crossed so as to give a key to the second coat.
The other drawback with trying to get too much on in one go is that it
slumps, often these get missed and the result is a concrete-like bulge
that is visible after plaster, wallpaper and several coats of emulsion.

Thanks for the info, Phil. Well I've been under a misapprehension, then.
I always thought render was something you could trowel on as thick as you
please. Oh well, it's One Coat plaster for me in future!

I've always had good results rendering. You were using 1:1:6? or something sloppier? It does tend to disconnect from the wall, the trick is to trowel over it with the trowel at a steep angle. This pushes the render under the edge back to the wall. Repeat a few times & it tends to stay there. I'm not sold on pva, unless the substrate's coming apart. Phil has most likely done far more rendering than I have though.


NT

F Murtz wrote:

http://www.northerntoolhire.com/prod...vity-Deflector



Bill

Link won't work.

That's odd.

Bill

It can be applied in 6mm coats, so if you've tried to do what everyone tries
to do the first time, IE fill up a half inch coat in one go, then the floor
is where most of it will go.

+1
and pva makes it slump more initially

On Tue, 18 Nov 2014 17:38:45 -0800, meow2222 wrote:

I've always had good results rendering. You were using 1:1:6? or
something sloppier? It does tend to disconnect from the wall, the trick
is to trowel over it with the trowel at a steep angle. This pushes the
render under the edge back to the wall. Repeat a few times & it tends to
stay there. I'm not sold on pva, unless the substrate's coming apart.
Phil has most likely done far more rendering than I have though.

Yep, there's clearly a different technique required here for render; what
works for plaster doesn't work for S&C. BTW, I'm using the pre-mixed-just-
add-water stuff from BnQ which states it's ideally suited to this
application.

On Tue, 18 Nov 2014 17:36:59 +0000 (UTC), Cursitor Doom
wrote:

Conclusion: use plaster for walls and render for floors and if you need
an outside wall rendered, get a proper tradesman in.

A tip I heard, and have not tried: if the stuff won't stick, add some tile
adhesive...


Thomas Prufer

On Tuesday, November 18, 2014 5:37:15 PM UTC, Cursitor Doom wrote:
I seem to have a natural knack for plastering. Not sure where it comes
from, but without wishing to blow my own trumpet, I can achieve a
'perfect finish' freehand with little effort. So when I came to having to
rendering a square meter of inside wall, I approached the task with
supreme confidence bordering on contempt.
What a mistake that was! Unlike plaster, render seems to have an
irresistible affinity with the floor - which is where nearly all of it
ended up. To add insult to injury, when I was carrying out final
smoothing on what modest proportion I had managed to apply, a large patch
in the middle simply fell out!
Conclusion: use plaster for walls and render for floors and if you need
an outside wall rendered, get a proper tradesman in.
Anyone else had nightmares rendering?

Don't use any PVA unless flakey, ruins the suction.
Rendering sand is sharp sand that's been sieved fine, add 5% building/soft sand to make it 'sticky' - no worries then.
Use a plasticiser to reduce the amount of water needed.
Phil.

Bill Wright wrote:
F Murtz wrote:

http://www.northerntoolhire.com/prod...vity-Deflector



Bill

Link won't work.

That's odd.

Bill
It must have decided it won't talk to Australians.
It says address not found.

F Murtz wrote:
Bill Wright wrote:
F Murtz wrote:

http://www.northerntoolhire.com/prod...vity-Deflector



Bill

Link won't work.

That's odd.

Bill
It must have decided it won't talk to Australians.
It says address not found.

I'm sure if the OP googles gravity deflector hire he'll be able to
locate the necessary equipment.

Bill

On 19/11/2014 11:03, Phil wrote:
On Tuesday, November 18, 2014 5:37:15 PM UTC, Cursitor Doom wrote:
I seem to have a natural knack for plastering. Not sure where it
comes from, but without wishing to blow my own trumpet, I can
achieve a 'perfect finish' freehand with little effort. So when I
came to having to rendering a square meter of inside wall, I
approached the task with supreme confidence bordering on contempt.
What a mistake that was! Unlike plaster, render seems to have an
irresistible affinity with the floor - which is where nearly all of
it ended up. To add insult to injury, when I was carrying out
final smoothing on what modest proportion I had managed to apply, a
large patch in the middle simply fell out! Conclusion: use plaster
for walls and render for floors and if you need an outside wall
rendered, get a proper tradesman in. Anyone else had nightmares
rendering?

Don't use any PVA unless flakey, ruins the suction. Rendering sand is
sharp sand that's been sieved fine, add 5% building/soft sand to
make it 'sticky' - no worries then. Use a plasticiser to reduce the
amount of water needed. Phil.


Pva reduces the initial grab, but a few extra sweeps of the towel
usually sorts that out. I find it produces a better bond in the end.
Trouble is, a surface doesn't have to be visibly flakey to be too
porous, so I pva by default

On Wed, 19 Nov 2014 14:05:56 +0000, Bill Wright wrote:

I'm sure if the OP googles gravity deflector hire he'll be able to
locate the necessary equipment.

He'll need a reverse polarity one for the southern hemisphere
otherwise it will always end up on the floor!

--

TOJ.

On 19/11/2014 14:05, Bill Wright wrote:
I'm sure if the OP googles gravity deflector hire he'll be able to
locate the necessary equipment.

I was expecting a nice funny spoof, not a 404.

Andy