Plastering cement rendered walls

[erm2706]

Hi all,

First I'd just like to say how impressed I am with the comments/assistance provided by members of this forum. Having just started to tinker around a bit at home, these threads have been brilliant!

Now to my problem ...

We've just renewed the ceilings and cornice in a number of rooms (batten and fresh board over original) due to sagging/cracking and the weight of dust in the ceiling cavity!

Having just completed painting etc, the contrast with the cement rendered walls which is quite stark with them now well and truly starting to show their age (why is it you do one job and find it leads to ten more to keep everything loloking good?).

I thought about plastering the walls as plasterboard would not only be difficult around exiting fittings etc but it would also prove problematic considering I wouldn't want to replace the recently repalced cornice.

Is plastering the way to go and is this a tradesman only job or one a DIY'er can pick up easily? The trouble we went through just to get a plasterer to redo the ceilings has been a saga in itself ... and finding someone to do actual plastering might well prove nigh on impossible!

[Pulse]

What sort of walls are they? Is it a true cement render finish or is it old hard plaster finish. If the place is old it is likely to be hard plaster. If it is drummy, then it becomes a harder job. If not then just skim coat with a topping compound.


Cheers
Pulse

[johnc]

Like pulse said, if you take a stanley knife or chisel and cut into the surface it should be a thin white top coat of plaster over a very crumbly sand/lime base coat. If that is what you have got it is an old home with solid plaster walls, which may or may not be sound, its meant to be a weak coat, strong ones only crack. If you can find a solid plasterer in the book you might be able to get them around to have a look, but depending on the condition you can skim coat and repaint if the base is sound.

[erm2706]

Thanks for the quick response guys.

The walls are definately cement render and do not have an existing layer of plaster (my parents also have a double brick house however theirs does have a coat of plaster.) Haven't noticed any loose render or drumminess, it's just that for whatever reason (wear and tear over the ages most likely) the surface is not consistent with various small holes/marks etc throughout.

If I skim coat a topping compound, how easy is this for a novice to apply to get a reasonable result and can it be applied over paint or does this need to be stripped? I've surfed the web for info however other than finding CSR's Gyprock or Boral's website which mentions a topping compound but not application details, I'm at a bit of a loss.

Cheers.

[ED T]

With no previous experience I skim coated all the walls of my house. They were originally painted cement render.

I trained at the bottom of the stairwell where no-one goes. The rest of the house was a breeze.

Cleaned the walls down with sugar soap.
Spotted in defects and sand them down.
One skim coat.
Sand down.
Another skim coat (very thin)
Very light sand.
Paint.

I used CSR Gyprock Joint Cement, applied with a soft blade about 30cm wide.

Tricks I learned were

Keep each coat thin
Don't coat over an irregularity. The blade will ride over it, then turn the irregularity into a mountain, which will cost you a lot of elbow grease to sand off. Any grit in the mix you are aplying will cause problems.
Keep each coat thin. All youshould really need to sand off are the feathers from the edge of the blade.
And finally, keep each coat thin.

Ed T

[Cliff Rogers]

G'day.


We had a painter give us a quote on repainting the cubby in the hills & he said he wanted to do it right & not just slap another coat over the old stuff.

What he explained was very similar to what Ed said.

He didn't say 7 times that the coats of plaster had to be thin. :D
He did say that it would make his quote more expensive than a slap dab job & he said that about 7 times.

[ThePope]

Depending on the contition of the render, if not too bad, what about a textured paint finish. It would be a whole hell of a lot easier/quicker than doing a skim coat and it would cover a lot of sins, though certainly not all.

Though ED T seems happy with his result, plastering is quite difficult to do properly. It all depends of the end result your after and what you'd find acceptable, if you want a nice smooth finish like a gyprocked wall then you need to do a skim coat otherwise try out some of the various paint finishes that are available.

[Pulse]

was the painter 7 times more expensive too?

[Cliff Rogers]

Trouble with textured paint finish is that it collects dust & mould & becomes hard to clean.


We didn't bother gettinga another quote but he was more expensive than we expected, even though he warned us.

[ED T]

ThePope (or should we call you Benny 16 ?)


Though ED T seems happy with his result, plastering is quite difficult to do properly.

I was not doing a plastering job. That is a job best left for professionals. I already had a sound, even base to work on (the work of a good plasterer).

Mine was more of a paint job with a thick paint - just using the blade to ride over the peaks of the rendered surface, while filling the valleys around them.

Ed T

[erm2706]

Thanks for the advice (not sure if it helped much but gave me a laugh!)

I might have a play around a bit in an inconspicuous area and go from there - that is unless anyone else has any thoughts.