Plastering - why leave an inch unplastered at bottom of wall?
 

Hi, I understand this is the norm - but I wonder why - is it to do
with expansion / rising damp or something?

Plastering - why leave an inch unplastered at bottom of wall?
 

"tester" wrote in message
...

Hi, I understand this is the norm - but I wonder why - is it to do
with expansion / rising damp or something?

So that you don't pick up all the dust and crap on the floor and add it into
your plaster finish.

Plastering - why leave an inch unplastered at bottom of wall?
 

Franko wrote:
"tester" wrote in message
...
Hi, I understand this is the norm - but I wonder why - is it to do
with expansion / rising damp or something?

It shouldn't go below the danp-proof course, for sure - if it does then
it often causes problems. I've many times had to cut in back when
refurbishing, having ripped off the old skirtings; it certainly helps.

So that you don't pick up all the dust and crap on the floor and add it into
your plaster finish.

That too! I reckon that's the only reason your average plasterer
doesn't go right to the ground - the take about as much notice of DPCs
as they do electrical sockets. I had one in last week doing some
skimming, and I was tearing my hair out reminding him to plaster *lower*
than the 4" from the floor required to be covered by my skirtings (the
old skirting having gone, and the wall behind being too grotty for him
to take his trowel anywhere near...!)

David

Plastering - why leave an inch unplastered at bottom of wall?
 

Lobster wrote:
Franko wrote:
"tester" wrote in message
...
Hi, I understand this is the norm - but I wonder why - is it to do
with expansion / rising damp or something?

It shouldn't go below the danp-proof course, for sure - if it does then
it often causes problems. I've many times had to cut in back when
refurbishing, having ripped off the old skirtings; it certainly helps.

So that you don't pick up all the dust and crap on the floor and add
it into your plaster finish.


Oh and PS - the other reason, which also applies to first-floor and
higher levels (ie, no DPC) is that you can get floorboards out again
after the plaster's gone off...)

David

Plastering - why leave an inch unplastered at bottom of wall?
 

On Wed, 28 Mar 2007 20:13:35 GMT, Lobster
wrote:

Franko wrote:
"tester" wrote in message
...
Hi, I understand this is the norm - but I wonder why - is it to do
with expansion / rising damp or something?

It shouldn't go below the danp-proof course, for sure - if it does then
it often causes problems. I've many times had to cut in back when
refurbishing, having ripped off the old skirtings; it certainly helps.

So that you don't pick up all the dust and crap on the floor and add it into
your plaster finish.

That too! I reckon that's the only reason your average plasterer
doesn't go right to the ground - the take about as much notice of DPCs
as they do electrical sockets. I had one in last week doing some
skimming, and I was tearing my hair out reminding him to plaster *lower*
than the 4" from the floor required to be covered by my skirtings (the
old skirting having gone, and the wall behind being too grotty for him
to take his trowel anywhere near...!)

David

The DPC is below the floor surely?

Plastering - why leave an inch unplastered at bottom of wall?
 

On Mar 28, 8:39 pm, tester wrote:
Hi, I understand this is the norm - but I wonder why - is it to do
with expansion / rising damp or something?

A floor carries an amazing amount of vibration. So much so that if the
plasterboard was in contact with it, the fixings would fail and the
joints would crack. There is also some sound deadening involved.

Half inch gaps are the minimum requirement. Much more than that and
you run the risk of having problems with fixing skirting board.

Another point to not is that with dot and dab techniques, the
adjustment to plumb is done with packers under the board.

Plastering - why leave an inch unplastered at bottom of wall?
 

FKruger wrote:
On Wed, 28 Mar 2007 20:13:35 GMT, Lobster
wrote:

Franko wrote:
"tester" wrote in message
...
Hi, I understand this is the norm - but I wonder why - is it to do
with expansion / rising damp or something?
It shouldn't go below the danp-proof course, for sure - if it does then
it often causes problems. I've many times had to cut in back when
refurbishing, having ripped off the old skirtings; it certainly helps.

So that you don't pick up all the dust and crap on the floor and add it into
your plaster finish.
That too! I reckon that's the only reason your average plasterer
doesn't go right to the ground - the take about as much notice of DPCs
as they do electrical sockets. I had one in last week doing some
skimming, and I was tearing my hair out reminding him to plaster *lower*
than the 4" from the floor required to be covered by my skirtings (the
old skirting having gone, and the wall behind being too grotty for him
to take his trowel anywhere near...!)

David

The DPC is below the floor surely?

Well allegedly I suppose. I suppose I'm really thinking of old
properties *without* a physical DPC, where it's definitely not going to
be a Good Thing having plaster down to the ground. Then again, the old
house I'm refurbishing at the moment does have a DPC, but that's at
about 1" above the solid floor, and it had been breached by plaster.
Don't think there's a membrane under the floor though.

David

Plastering - why leave an inch unplastered at bottom of wall?
 

"Weatherlawyer" wrote in message
ups.com...
On Mar 28, 8:39 pm, tester wrote:
Hi, I understand this is the norm - but I wonder why - is it to do
with expansion / rising damp or something?

A floor carries an amazing amount of vibration. So much so that if the
plasterboard was in contact with it, the fixings would fail and the
joints would crack. There is also some sound deadening involved.

Half inch gaps are the minimum requirement. Much more than that and
you run the risk of having problems with fixing skirting board.

Another point to not is that with dot and dab techniques, the
adjustment to plumb is done with packers under the board.


Can you, please, expand on that? What packers, where? I'd assumed that dot &
dab techniques just plonked sufficient plaster to permit the board to be
'plumbed'

--

Brian

Plastering - why leave an inch unplastered at bottom of wall?
 

"Brian Sharrock" wrote in message
...

Can you, please, expand on that? What packers, where? I'd assumed that dot
& dab techniques just plonked sufficient plaster to permit the board to
be 'plumbed'

When you dot & dab, it is almost impossible to cut the board to the exact
height needed - if it is too long or the ceiling is a bit out, the board
will become wedged and you'll never get it back plumb and straight. If it is
too short - you will have no way of lifting the board to create a tidy
ceiling line.
I was a dot & dabber for about 15 years (till back went) and always used a
1/2" offcut piece of board under the board to enable a board lifter to be
inserted to jack up the board tightly to the ceiling after levelling and if
necessary adding packing pieces - hardboard or asbestolux offcuts, nails,
screws or anything to hand to create a tight fit.
Of course you have to be careful about skirting fixings so only use the
minimum packing necessary to enable a board lifter to be used.

Plastering - why leave an inch unplastered at bottom of wall?
 

"Franko" wrote in message
...

"Brian Sharrock" wrote in message
...

Can you, please, expand on that? What packers, where? I'd assumed that
dot & dab techniques just plonked sufficient plaster to permit the board
to be 'plumbed'

When you dot & dab, it is almost impossible to cut the board to the exact
height needed - if it is too long or the ceiling is a bit out, the board
will become wedged and you'll never get it back plumb and straight. If it
is too short - you will have no way of lifting the board to create a tidy
ceiling line.
I was a dot & dabber for about 15 years (till back went) and always used a
1/2" offcut piece of board under the board to enable a board lifter to be
inserted to jack up the board tightly to the ceiling after levelling and
if necessary adding packing pieces - hardboard or asbestolux offcuts,
nails, screws or anything to hand to create a tight fit.
Of course you have to be careful about skirting fixings so only use the
minimum packing necessary to enable a board lifter to be used.
Hmm; thanks ... I think;
Isn't one supposed to board the ceiling first? ... then lift boards towards
the ceiling but maintaining the edge vertical (plumb) ... any gaps between a
sloping ceiling and the top edges pf the vertical boards to be concealed by
coving / caulking.
{I thought you were referring to 'out-of-plumb' in the 'towards the room'
axis.

--

Brian

Plastering - why leave an inch unplastered at bottom of wall?
 

"Brian Sharrock" wrote in message
...

"Franko" wrote in message
...

"Brian Sharrock" wrote in message
...

Can you, please, expand on that? What packers, where? I'd assumed that
dot & dab techniques just plonked sufficient plaster to permit the
board to be 'plumbed'

When you dot & dab, it is almost impossible to cut the board to the exact
height needed - if it is too long or the ceiling is a bit out, the board
will become wedged and you'll never get it back plumb and straight. If it
is too short - you will have no way of lifting the board to create a tidy
ceiling line.
I was a dot & dabber for about 15 years (till back went) and always used
a 1/2" offcut piece of board under the board to enable a board lifter to
be inserted to jack up the board tightly to the ceiling after levelling
and if necessary adding packing pieces - hardboard or asbestolux offcuts,
nails, screws or anything to hand to create a tight fit.
Of course you have to be careful about skirting fixings so only use the
minimum packing necessary to enable a board lifter to be used.

Hmm; thanks ... I think;
Isn't one supposed to board the ceiling first? ... then lift boards
towards the ceiling but maintaining the edge vertical (plumb) ... any gaps
between a sloping ceiling and the top edges pf the vertical boards to be
concealed by coving / caulking.
{I thought you were referring to 'out-of-plumb' in the 'towards the room'
axis.

You are correct - the ceiling should be boarded first and the wallboard
should be plumb in both axis but there should be no gaps if done correctly,
a bit of trimming here and there is needed sometimes.
If there is coving being fitted, any gaps will be covered but the job will
look unsightly until the cove is fitted.
If there is no coving being fitted, any gaps can be pre-filled before
jointing or plastering but this is not an ideal situation as there is a
strong likelihood of cracking around the filled area as the building drys
out - it also looks unsightly.