I need to repair my Dad's pond which is a "cement rendering on a brick wall"
sort of construction. The bricks are in fairly poor shape behind the render
which has come away, due to possibly freeze-thaw, but still pretty much
solid enough and will provide a good key to render to. The bricks are fairly
damp with no possibility of drying out though, but perhaps this is not a
problem

What I would like to know is what preparations should I do to the brickwork
before applying the render, and what mix should the render be made up of -
any special sand / cement / additives ( e.g some Feb chemical?) to make it
stick well and waterproof / impervious to stop it leaking ? Should it be
applied as dry or as wet as possible to help make it stick ? The bricks
will remain damp behind the render.

Thanks,

Nick

On May 6, 4:02 pm, "Nick" wrote:
I need to repair my Dad's pond which is a "cement rendering on a brick wall"
sort of construction. The bricks are in fairly poor shape behind the render
which has come away, due to possibly freeze-thaw, but still pretty much
solid enough and will provide a good key to render to. The bricks are fairly
damp with no possibility of drying out though, but perhaps this is not a
problem

What I would like to know is what preparations should I do to the brickwork
before applying the render, and what mix should the render be made up of -
any special sand / cement / additives ( e.g some Feb chemical?) to make it
stick well and waterproof / impervious to stop it leaking ? Should it be
applied as dry or as wet as possible to help make it stick ? The bricks
will remain damp behind the render.

As long as the bricks are clean of scum and algae, there should be no
problem with using a 4 or 5 to one mix of sad and cement. Break off
all the loose and friable material.

Just give the surface to be rendered a quick wire brushing and then
slap it on.

Being wet, the bricks will allow better adhesion than if they were
dry. Perhaps someone will be along to recommend and additive for
waterproofing but I'd steer clear of such chemicals in a fish pond.

I wouldn't even use Feb and certainly not use washing up liquid as a
plasticiser.

As long as the bricks are clean of scum and algae, there should be no
problem with using a 4 or 5 to one mix of sad and cement. Break off
all the loose and friable material.

Just give the surface to be rendered a quick wire brushing and then
slap it on.

Being wet, the bricks will allow better adhesion than if they were
dry. Perhaps someone will be along to recommend and additive for
waterproofing but I'd steer clear of such chemicals in a fish pond.

I wouldn't even use Feb and certainly not use washing up liquid as a
plasticiser.

Hi,
Thanks for the reply - no its mainly decorative, few plants not always water
and definitely no fish, but I need to plan
for waterproofness in case one day he wants to fill it.

Thanks,
Nick