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Default Plaster Cracking

When plastering a brick wall the plaster has cracks in it when drying
- it this because I should have use a paint on barrier? If so what is
the trade name of a suitable barrier?

Will the cracking affect the ability of the plaster to remaining stuck
to the wall? - the finish doesn't matter (and it needs more coats
anyway) as I will be tiling over it.
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Default Plaster Cracking


"405 TD Estate" wrote in message
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When plastering a brick wall the plaster has cracks in it when drying
- it this because I should have use a paint on barrier? If so what is
the trade name of a suitable barrier?

Will the cracking affect the ability of the plaster to remaining stuck
to the wall? - the finish doesn't matter (and it needs more coats
anyway) as I will be tiling over it.


What did you use to plaster the brick?
Does the wall get warm ie is there a rad on that wall?
Was the plaster within the date stamp?


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Default Plaster Cracking

In article ,
405 TD Estate writes:
When plastering a brick wall the plaster has cracks in it when drying
- it this because I should have use a paint on barrier? If so what is
the trade name of a suitable barrier?

Will the cracking affect the ability of the plaster to remaining stuck
to the wall? - the finish doesn't matter (and it needs more coats
anyway) as I will be tiling over it.


What plaster did you use?
What type of wall (particularly water absorbtion)?

Plaster shrinks as it sets. Too thick a layer can crack.
It won't matter in bonding coat. Make sure the finish
coat is a thin layer (which shrinks by getting thinner)
rather than a thick layer which will also crack across.

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

Plaster was multi finish from BnQ

There is an insulated water cylinder on the other side of the wall in
a cupboard

Plaster was well within the date stamp

Wall is an internal brick wall - some of the bricks have lost the
smooth oustide finish which came off removing cement there previously

The plaster was put directly onto the brick.

Today there is cracking on thinner layers put on top of the base
plaster coat as well. All carcks are quite pronounced 1-2mm wide.
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Default Plaster Cracking


"405 TD Estate" wrote in message
...
Plaster was multi finish from BnQ

There is an insulated water cylinder on the other side of the wall in
a cupboard

Plaster was well within the date stamp

Wall is an internal brick wall - some of the bricks have lost the
smooth oustide finish which came off removing cement there previously

The plaster was put directly onto the brick.

Today there is cracking on thinner layers put on top of the base
plaster coat as well. All carcks are quite pronounced 1-2mm wide.


Damn! you need a base coat on exposed brickwork first ie carling bonding
coat or dot&dab the brickwork.




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Default Plaster Cracking

In article ,
"George" writes:

"405 TD Estate" wrote in message
...
Plaster was multi finish from BnQ

There is an insulated water cylinder on the other side of the wall in
a cupboard

Plaster was well within the date stamp

Wall is an internal brick wall - some of the bricks have lost the
smooth oustide finish which came off removing cement there previously

The plaster was put directly onto the brick.

Today there is cracking on thinner layers put on top of the base
plaster coat as well. All carcks are quite pronounced 1-2mm wide.


Damn! you need a base coat on exposed brickwork first ie carling bonding
coat or dot&dab the brickwork.


Not sure how easily rescuable this is going to be now...

If the finish coat (which you've used as a scratch coat) is well
bonded to the brickwork and the surface is flat, you might be
able to get away with just a proper finish coat reskim on top.

If the finish coat isn't well bonded to the brickwork (and finish
coat isn't wonderful at bonding), you'll have to hack all the loose
stuff off.

If the surface isn't flat, then that will need leveling off with
something like bonding coat before skimming. Use a straight edge
(i.e. a piece of unwarped planned timber) to check for flatness.

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

405 TD Estate wrote:
Plaster was multi finish from BnQ


The word 'finish' means it's a top coat, IE it requires a backing of some
kind, either plasterboard or backing plaster such as bonding, browning or
render.

There is an insulated water cylinder on the other side of the wall in
a cupboard

Plaster was well within the date stamp

Wall is an internal brick wall - some of the bricks have lost the
smooth oustide finish which came off removing cement there previously

The plaster was put directly onto the brick.


see above.

Today there is cracking on thinner layers put on top of the base
plaster coat as well. All carcks are quite pronounced 1-2mm wide.


It's only meant o be put on at about 4 mm maximum, any thicker, regardless
of the backing and it cracks up.

There is little you can do now to rectify this short of hacking it all off
and starting again if you want to paint the wall, but as you stated earlier
you intend tiling(?) - in which case, if the plaster is sound (tap it with
your fingernails - if it's not stuck it will sound hollow behind) then you
can tile over it, but you may require a few coats of diluted PVA to kill
some of the suction.

HTH


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