Cracking plaster
 

Hi folks,

My house is exactly 100 years old. About 3 years ago most of the plasterwork
was skimmed. The original plaster was left in place and a new, smooth coat
was applied on top. I moved in 2 years ago.

The problem is that the old plaster foundation on which the skim was applied
doesn't appear to be sound in some places. In some areas the base isn't
stuck to the bricks so when I to apply pressure with my hand, I can feel it
moving up to and away from the brick by a few mm. Where this is very bad I'm
having to arrange for all plaster to be hacked back to brickwork and new
plaster applied, because the plaster is cracking all over, but there's one
area where there's just one crack, running from the top corner of a door
frame diagonally up to the ceiling. I previously repaired it by scoring it
out, filling it and repainting, but after a year the crack has returned.

I really don't want to hack this entire wall back for one crack - can anyone
advise a solution that'll last?

TIA.

Cracking plaster
 

JustMe wrote:
Hi folks,

My house is exactly 100 years old. About 3 years ago most of the
plasterwork was skimmed. The original plaster was left in place and a
new, smooth coat was applied on top. I moved in 2 years ago.

The problem is that the old plaster foundation on which the skim was
applied doesn't appear to be sound in some places. In some areas the
base isn't stuck to the bricks so when I to apply pressure with my
hand, I can feel it moving up to and away from the brick by a few mm.

This is the problem with skimming over 100 year old plaster, the plaster is
crumbly and weak its inevitable cracks will appear due to slight foundation
movment,banging of doors, ect.

The crack above the door is either of the two scenarios above again the
plaster in that area is probably as you have stated the old plaster is
coming away from wall, I doubt you will make good whichever method is used
to repair it?

--
Sir Benjamin Middlethwaite

Cracking plaster
 

"JustMe" wrote
Hi folks,

My house is exactly 100 years old. About 3 years ago most of the
plasterwork
was skimmed. The original plaster was left in place and a new, smooth coat
was applied on top. I moved in 2 years ago.

The problem is that the old plaster foundation on which the skim was
applied
doesn't appear to be sound in some places. In some areas the base isn't
stuck to the bricks so when I to apply pressure with my hand, I can feel
it
moving up to and away from the brick by a few mm. Where this is very bad
I'm
having to arrange for all plaster to be hacked back to brickwork and new
plaster applied, because the plaster is cracking all over, but there's one
area where there's just one crack, running from the top corner of a door
frame diagonally up to the ceiling. I previously repaired it by scoring it
out, filling it and repainting, but after a year the crack has returned.

I really don't want to hack this entire wall back for one crack - can
anyone
advise a solution that'll last?

TIA.

If the plaster around this crack is loose, putting filler over loose plaster
will not last long as opening and closing the door, and movement of the door
frame and loose plaster, will eventually cause the plaster to crack again.
You could try enlarging the crack to a wider channel, say 2 or 3
centimetres - the larger amount of filler might be stronger and longer
lasting.

Cracking plaster
 

In article ,
"JustMe" writes:
Hi folks,

My house is exactly 100 years old. About 3 years ago most of the plasterwork
was skimmed. The original plaster was left in place and a new, smooth coat
was applied on top. I moved in 2 years ago.

The problem is that the old plaster foundation on which the skim was applied
doesn't appear to be sound in some places. In some areas the base isn't
stuck to the bricks so when I to apply pressure with my hand, I can feel it
moving up to and away from the brick by a few mm. Where this is very bad I'm
having to arrange for all plaster to be hacked back to brickwork and new
plaster applied, because the plaster is cracking all over,

As you suggest, the plaster wasn't in a fit state for reskimming.
You don't have to fix every last bit where keying is lost with the
wall behind, but a large area of movement like this does need
fixing, and it's very easy to do just before you reskim the whole
wall. It could be dangerous to a small child or elderly person
if it all fell out on top of them.

but there's one
area where there's just one crack, running from the top corner of a door
frame diagonally up to the ceiling. I previously repaired it by scoring it
out, filling it and repainting, but after a year the crack has returned.

I really don't want to hack this entire wall back for one crack - can anyone
advise a solution that'll last?

That's a different situation. 100 year old house will be built
using lime mortar which allows the house to routinely move
around. The original lime plaster similarly moves, and the horse
hair in it prevents it forming large cracks. I assume the reskim
was done with gypsom (pink or grey) plaster, which isn't flexible,
so when there's movement in the wall behind, the gypsom plaster
will crack. Often this doesn't happen enough to worry about, but
if you have a crack where it does, then you could try raking it
out and filling with a more flexible filler such as decorator's
chalking. This shrinks as it sets, so you might need to go over
it 2-3 times to get a flat level finish. The more movement you
are getting in that crack, the wider strip you will need to rake
out and replace with flexible filler to accomodate the movement.
(I assume we're talking about hairline cracks here, rather than
something you can push a pencil in, which would be a different
problem.)

The other option would be to replaster with lime plaster, but
that probably won't work with just a reskim -- you would need to
replace the scratch coat too.

--
Andrew Gabriel

Cracking plaster
 

Paper the wall with lining paper, it will absorb hairline cracks.

Cracking plaster
 

Rednadnerb wrote:
Paper the wall with lining paper, it will absorb hairline cracks.


Quite right.
I have a couple of rooms where only the lining paper is keeping the
plaster on the wall but they look fine. Nature of the beast. Either
that or have the whole lot hacked off if you (and your neighbours) can
stand the dust

Cracking plaster
 

Stuart Noble wrote:
Rednadnerb wrote:
Paper the wall with lining paper, it will absorb hairline cracks.

Quite right.
I have a couple of rooms where only the lining paper is keeping the plaster
on the wall but they look fine. Nature of the beast. Either that or have the
whole lot hacked off if you (and your neighbours) can stand the dust

It sounds like a real pain to replace if you think you need to. And
there is no getting away with the fact that lath and plaster can be a
major problem. Great if you have clay soil in the garden though.

I would choose the easy option of ignoring it until it fell off. Then
strip the wall it fell from and redo that with lime and sand then a
lime plaster.

After that I would consider myself capable of tackling the next one
with modern plaster mixes. I suggest the old fashioned mixes to allow
you time to work with them if you have never plastered anything before.

Of course if you don't fancy getting stuck in, put pasterboard up and
skim that. Doing it that way is also a piece of cake. I find plastering
quite relaxing. Messes with your cuticles though.

Cracking plaster
 

In article . com,
"Weatherlawyer" writes:
Of course if you don't fancy getting stuck in, put pasterboard up and
skim that. Doing it that way is also a piece of cake. I find plastering
quite relaxing. Messes with your cuticles though.

Plaster and cement can do quite nasty things to your
skin. Use a barrier cream when working with them.

--
Andrew Gabriel

Cracking plaster
 

JustMe wrote:
Hi folks,

My house is exactly 100 years old. About 3 years ago most of the
plasterwork was skimmed. The original plaster was left in place and a
new, smooth coat was applied on top. I moved in 2 years ago.

The problem is that the old plaster foundation on which the skim was
applied doesn't appear to be sound in some places. In some areas the
base isn't stuck to the bricks so when I to apply pressure with my
hand, I can feel it moving up to and away from the brick by a few mm.
Where this is very bad I'm having to arrange for all plaster to be
hacked back to brickwork and new plaster applied, because the plaster
is cracking all over, but there's one area where there's just one
crack, running from the top corner of a door frame diagonally up to
the ceiling. I previously repaired it by scoring it out, filling it
and repainting, but after a year the crack has returned.

I really don't want to hack this entire wall back for one crack - can
anyone advise a solution that'll last?

TIA.

The crack above the door frame is a cause for concern, especially since it
has returned....if it were my house, I would remove the plaster above this
door and check the lintel, even if the lintle is sound, there's a
possibility that the brickwork has slipped, probably because of subsidence,
what's the exterior brickwork like around that area?

Cracking plaster
 

...cracking cheese too Gromit.

Sorry, couldn't resist.

Cracking plaster
 

"Andrew Gabriel" wrote in message
...
In article ,
"JustMe" writes:
Hi folks,

My house is exactly 100 years old. About 3 years ago most of the
plasterwork
was skimmed. The original plaster was left in place and a new, smooth
coat
was applied on top. I moved in 2 years ago.

The problem is that the old plaster foundation on which the skim was
applied
doesn't appear to be sound in some places. In some areas the base isn't
stuck to the bricks so when I to apply pressure with my hand, I can feel
it
moving up to and away from the brick by a few mm. Where this is very bad
I'm
having to arrange for all plaster to be hacked back to brickwork and new
plaster applied, because the plaster is cracking all over,

As you suggest, the plaster wasn't in a fit state for reskimming.
You don't have to fix every last bit where keying is lost with the
wall behind, but a large area of movement like this does need
fixing, and it's very easy to do just before you reskim the whole
wall. It could be dangerous to a small child or elderly person
if it all fell out on top of them.

It isn't so loose as to be a danger, but the area with multiple cracks is to
be hacked and replastered for cosmetic reasons. It's the single crack area
(different wall, different part of the house) which I'm going to DIY.

but there's one
area where there's just one crack, running from the top corner of a door
frame diagonally up to the ceiling. I previously repaired it by scoring
it
out, filling it and repainting, but after a year the crack has returned.

I really don't want to hack this entire wall back for one crack - can
anyone
advise a solution that'll last?

That's a different situation. 100 year old house will be built
using lime mortar which allows the house to routinely move
around. The original lime plaster similarly moves, and the horse
hair in it prevents it forming large cracks. I assume the reskim
was done with gypsom (pink or grey) plaster, which isn't flexible,
so when there's movement in the wall behind, the gypsom plaster
will crack. Often this doesn't happen enough to worry about, but
if you have a crack where it does, then you could try raking it
out and filling with a more flexible filler such as decorator's
chalking. This shrinks as it sets, so you might need to go over
it 2-3 times to get a flat level finish. The more movement you
are getting in that crack, the wider strip you will need to rake
out and replace with flexible filler to accomodate the movement.
(I assume we're talking about hairline cracks here, rather than
something you can push a pencil in, which would be a different
problem.)

That description seems pretty accurate and, yes, hairline.

The other option would be to replaster with lime plaster, but
that probably won't work with just a reskim -- you would need to
replace the scratch coat too.

One crack in an otherwise sound wall - I'd rather simply repair the crack -
not heard of "decorator's chalking" before but will look in B&Q later.

Andrew Gabriel

Thanks Andrew :)

Cracking plaster
 

"Phil L" wrote in message
...
JustMe wrote:
Hi folks,

My house is exactly 100 years old. About 3 years ago most of the
plasterwork was skimmed. The original plaster was left in place and a
new, smooth coat was applied on top. I moved in 2 years ago.

The problem is that the old plaster foundation on which the skim was
applied doesn't appear to be sound in some places. In some areas the
base isn't stuck to the bricks so when I to apply pressure with my
hand, I can feel it moving up to and away from the brick by a few mm.
Where this is very bad I'm having to arrange for all plaster to be
hacked back to brickwork and new plaster applied, because the plaster
is cracking all over, but there's one area where there's just one
crack, running from the top corner of a door frame diagonally up to
the ceiling. I previously repaired it by scoring it out, filling it
and repainting, but after a year the crack has returned.

I really don't want to hack this entire wall back for one crack - can
anyone advise a solution that'll last?

TIA.

The crack above the door frame is a cause for concern, especially since it
has returned....if it were my house, I would remove the plaster above this
door and check the lintel, even if the lintle is sound, there's a
possibility that the brickwork has slipped, probably because of
subsidence,
what's the exterior brickwork like around that area?

It's an internal, dividing wall. The single crack area is downstairs (ground
floor), the multiple crack area is upstairs (same side of same wall, above
floor divide).

The upstairs area is worse because the wall isn't perfectly flat, but
curved. In installing a false ceiling above the area of the upstairs wall, a
piece of 2x2 batton was screwed VERY tight along the wall. The wood being
reasonably straight and the wall being slightly curved, the wall was pulled
a little by the tightly screwed wood, hence loads of cracks appeared in the
loose plaster. Upstairs is a hack back to brickwork and replaster job, but
downstairs is a single crack that was there when I moved in (before the
false ceiling job), which I carefully scored and filled before and which has
reappeared.

AFAIK the house isn't moving (survey info, other houses in the terrace, no
other indicators on my house etc all point to the ground being sound).
Exterior brickwork front and back (no sides cos mid-terrace) is sound.

Cracking plaster
 

JustMe wrote:

It's an internal, dividing wall. The single crack area is downstairs
(ground floor), the multiple crack area is upstairs (same side of
same wall, above floor divide).


So the crack effectively goes from floor to roof? (discount the downstairs
doorframe because it only starts above this)

The upstairs area is worse because the wall isn't perfectly flat, but
curved. In installing a false ceiling above the area of the upstairs
wall, a piece of 2x2 batton was screwed VERY tight along the wall.

I'd get this looked at ASAP, simply carrying out cosmetic work is a waste of
money until the underlying cause of the crack has been remedied.


The wood being reasonably straight and the wall being slightly
curved, the wall was pulled a little by the tightly screwed wood,
hence loads of cracks appeared in the loose plaster. Upstairs is a
hack back to brickwork and replaster job, but downstairs is a single
crack that was there when I moved in (before the false ceiling job),
which I carefully scored and filled before and which has reappeared.

That tells you that it's getting worse - normal plaster cracks don't
reappear, the crack *must* be in the brickwork behind.


AFAIK the house isn't moving (survey info, other houses in the
terrace, no other indicators on my house etc all point to the ground
being sound). Exterior brickwork front and back (no sides cos
mid-terrace) is sound.

All exterior brickwork sounds ok, this door downstairs which has the crack
above it and underneath where the upstairs wall has slipped - has everyone
in the block got this door in this position or has someone knocked it
through in the (recent - ish) past? - my money is on the lintel - it's
either rotted away or there isn't one in.

Cracking plaster
 

"Phil L" wrote in message
k...
JustMe wrote:

It's an internal, dividing wall. The single crack area is downstairs
(ground floor), the multiple crack area is upstairs (same side of
same wall, above floor divide).


So the crack effectively goes from floor to roof? (discount the downstairs
doorframe because it only starts above this)

The upstairs area is worse because the wall isn't perfectly flat, but
curved. In installing a false ceiling above the area of the upstairs
wall, a piece of 2x2 batton was screwed VERY tight along the wall.

I'd get this looked at ASAP, simply carrying out cosmetic work is a waste
of
money until the underlying cause of the crack has been remedied.


The wood being reasonably straight and the wall being slightly
curved, the wall was pulled a little by the tightly screwed wood,
hence loads of cracks appeared in the loose plaster. Upstairs is a
hack back to brickwork and replaster job, but downstairs is a single
crack that was there when I moved in (before the false ceiling job),
which I carefully scored and filled before and which has reappeared.

That tells you that it's getting worse - normal plaster cracks don't
reappear, the crack *must* be in the brickwork behind.


AFAIK the house isn't moving (survey info, other houses in the
terrace, no other indicators on my house etc all point to the ground
being sound). Exterior brickwork front and back (no sides cos
mid-terrace) is sound.

All exterior brickwork sounds ok, this door downstairs which has the crack
above it and underneath where the upstairs wall has slipped - has everyone
in the block got this door in this position or has someone knocked it
through in the (recent - ish) past? - my money is on the lintel - it's
either rotted away or there isn't one in.

You were quite right! No lintel of any description. Even the top of the door
case sits inside the two sides (as opposed to resting on top which might
have provided a small bit of additional support.

So fitting a new lintel (and door case) next week, before fixing up the
rest.

Thanks for the advice.

Cracking plaster
 

JustMe wrote:
"Phil L" wrote in message
k...
JustMe wrote:

It's an internal, dividing wall. The single crack area is downstairs
(ground floor), the multiple crack area is upstairs (same side of
same wall, above floor divide).


So the crack effectively goes from floor to roof? (discount the
downstairs doorframe because it only starts above this)

The upstairs area is worse because the wall isn't perfectly flat,
but curved. In installing a false ceiling above the area of the
upstairs wall, a piece of 2x2 batton was screwed VERY tight along
the wall.

I'd get this looked at ASAP, simply carrying out cosmetic work is a
waste of money until the underlying cause of the crack has been
remedied.


The wood being reasonably straight and the wall being slightly
curved, the wall was pulled a little by the tightly screwed wood,
hence loads of cracks appeared in the loose plaster. Upstairs is a
hack back to brickwork and replaster job, but downstairs is a single
crack that was there when I moved in (before the false ceiling job),
which I carefully scored and filled before and which has reappeared.

That tells you that it's getting worse - normal plaster cracks don't
reappear, the crack *must* be in the brickwork behind.


AFAIK the house isn't moving (survey info, other houses in the
terrace, no other indicators on my house etc all point to the ground
being sound). Exterior brickwork front and back (no sides cos
mid-terrace) is sound.

All exterior brickwork sounds ok, this door downstairs which has the
crack above it and underneath where the upstairs wall has slipped -
has everyone in the block got this door in this position or has
someone knocked it through in the (recent - ish) past? - my money is
on the lintel - it's either rotted away or there isn't one in.

You were quite right! No lintel of any description. Even the top of
the door case sits inside the two sides (as opposed to resting on top
which might have provided a small bit of additional support.

So fitting a new lintel (and door case) next week, before fixing up
the rest.

Thanks for the advice.

Glad to be of help :-)