cornice question

[DrRazzle]

Hi all,

I have a Victorian cottage which was renoed in the last 15 years or so which means plasterboard but no cornices for that slick look. I am trying to return it to an original look and want to reinstate the cornices.

Issue is, while the walls look great, when I put a straight edge against them there are slight curves in and out.

Question is: If I put a dead straight cornice up against them are there going to be a few gaps which I will need to fill, or is there a bit of flex in the plaster (I doubt it), or should I go with an mdf cornice that has a bit of give but none of the appeal?

Cheers,
Raz

[munruben]

I am no expert but I would think there would be some flex in the cornice to allow for this kind of thing. I mean hey, how many walls are 100% true.

[Ronaldo451]

Raz,

I have just done similar with fairly wide cornices (210mm). As John says, there is a bit of give and flex over the length of the cornice- any minor gaps can be filled with cornice adhesive and wiped with a wet rag as you go. When painted white this is undetectable.

[seriph1]

It is a simple thing to successfully fill any reasonably small gaps with cornice cement of flexible caulk.

[DrRazzle]

Thanks very much. That should settle my fear.

[rod@plasterbrok]

Like the others have said, except I might add that if you have a section of wall that dives in giving you a gap that can be noticed, it is not that difficult to float the wall under the cornice to get rid of the gap. You can apply the cornice adhesive to the wall and use a straight edge like a spirit level to screed it level. You only need to come down the wall 600mm or so. Just blend it it inthis is much better that the bottom member of the cornice waving in and out.

Do it in 3 or 4 coats, between coats scrape it back level. If you use a spirit level and run over what you have filled the high points that need scraping will pick up a black mark from the metal of the level, showing you exactly where to scrape back.

Cheers Rod

[jags]

Are you talking gyprock cornice or plaster glass ?
gyprock cornice will bend more than plaster glass cornices .

i have just re done the old cornice at my place so that the newly created kitchen would have the same cornice on each wall.
it look great well worth the effort and extra couple of dollars compared to the stardard quarter round stuff .

by the way if you are using plaster glass be sure to seal it with plaster glass sealer before you paint it .

Rob

[Jacksin]

If Dr Razzles reno was cornice-less 15 years ago, I think he could have another problem with the new intended cornice adhering to the paint?
What say you Rod?

[rod@plasterbrok]

You can get around that Jack in various ways, perhaps the most secure method is to screw as well as uing cornice adhesive.

I would never stick cornice up straight onto a painted surface. If it is plasterboard I run a few knife cuts barely throught the surface paper layer and peel away most of the painted board above the cornice line.

There are many other ways, but the objective is to get a solid fixing ether mechanical (screws) or cornice adhesive to an absorbent or rough surface surface where it will grip.

cheers

[DrRazzle]

I expect that fixing the cornice to the wall is my next challenge, I was considering roughing up the plasterboard in some manner so I might experiment with the knife approach. Thanks for the advice Rod. And cheers Jacksin, I am going to go with the plaster cornice and do some screeding (thanks again Rod).