Bathroom cornice

[Metung]

My plasterer has let me down in that he was supposed to come back and put the cornice up in the bathrooms but won't answer my calls etc so I think I'll have a crack at it myself. Paid him the full amount too on that understanding because he seemed like such a reliable bloke. I have been thinking that maybe he knows something that I don't. Is there any problem putting cornice in bathrooms? One bathroom has polished granite tiles to the roof and the other has ceramic. I was wondering whether the cornice cement will stick to the tiles or should i fix through the cornice into the grout joins? Any advice would be much appreciated.

[rod@plasterbrok]

Hmm first mistake is never ever pay a tradie up when there is still work to be done!!

The cornice adhesive will not stick to the tiles.

Hopefully the tiles do not go all the way to the ceiling, usually they are down about 20mm or so. If this is the case I load up the gap above the tiles with cornice adhesive over filling it. Then put quite a large bead of cornice adhesive just below the center of the cornice and also along the top member.

The idea is that the cornice adhesive above the tiles and that along the center of the cornice meet together to form the bond required to hold the cornice. This can also work for cornice around kitchen cupboards.

You want to try to avoid the cornice adhesive oozing out on the bottom when you put the cornice up. You may find you have to put a temporary pin under the cornice to hold it in place, put the pin through the gap in the tiles.

Last thing is finish the bottom edge of the cornice to the tiles using a good quality paintable sealant.

This method is a bit fiddely at first but worth the effort.

Cheers Rod

[Metung]

Thanks for the advice Rod. A problem I may have is that the cornice is 90mm Sydney Cove which is relatively heavy and although I have the 20mm plus gap at the top of the tiles, if I understand you correctly, then due to the size of the cornice I will have trouble getting the adhesive on top of the tiles and that on the cornice to meet and so form the bond. Have I got this right and if so any further suggestions would be appreciated. Thanks.

[rod@plasterbrok]

If you follow what I mean, pin the cornice in place it will be embedded in a block of cornice adhesive that cant slip down the tiles as it is over the top of the tiles. I have installed all the cornice around my own kitchen cupboards using this method. They are 2 pack paint, I have not got a single crack after 6 years. I have a heavier decorative cornice than Sydney Cove, so I am sure it will be ok.

Cheers Rod

[Metung]

Thanks Rod, think I've got the idea now so I'll give it a go.

[familyguy]

About 5-6 months ago I did just what you are planning in my renovated bathroom, same sydney cove cornice as well. As an added precaution I put plaster board fasteners at an angle up through the cornice into the ceiling beams. I have seen them up to 75mm long so you usually don't have a problem hitting the beams, just buy a selection and if the 75mm ones are too long take it out and put in a shorter one. Fasteners are not normally used on cornice and if its done correctly are not needed but in the last few months I've replaced abot 8 or 9 cornices that have simply fallen down with one damaging an expensive antique dresser. In all instances the cornices were larger ornate types (inc 2 sydney cove types) that were put up over older smaller cornices and the cornice adhesive failed to adhere to the painted wall even though the wall had been scoured with a comb hammer or similar.

[RPMT]

tip from a good plasterer that i have known for years is to paint cemstick or bondcrete on the tile first and then apply the cornice cement.

failing that you could probably use cornice cement against the ceiling and white Sikaflex on the tile side... that will never let go! guaranteed!

[rod@plasterbrok]

This is not recomended RPMT I used to do the same thing years ago until I found that some plasters and paints are not compatible with bondcrete.

The last time I used bondcrete with plaster was when I had a repair to do on a painted surface. Within 2 weeks I was call back becase the patch was blistering. Where I had patched. The entire area I had patched just pulled off the ceiling. I took the "slabs" of plaster to be analysed but when I told them I had used bondcrete I was told it was not compatible.

Therefore it is best not to risk it.

The best methods are as described above.

[Metung]

Unfortunately I had tiled a little too close to the ceiling to be able to use Rod's idea effectively so what I ended up doing was gluing a 30mm strip of plaster just above where the cornice meets the wall and then loading up the cornice with cement in that area in the hope that a reasonable bond would form. I also assumed that the builder's bond that I used to stick the plaster strip with will last. I also noticed that the cement seemed to be doing a pretty reasonable job of sticking to the tile. Time will tell. Thanks for all the advice. I'll let you know when it falls off

[RPMT]

This is not recomended RPMT I used to do the same thing years ago until I found that some plasters and paints are not compatible with bondcrete.

The last time I used bondcrete with plaster was when I had a repair to do on a painted surface. Within 2 weeks I was call back becase the patch was blistering. Where I had patched. The entire area I had patched just pulled off the ceiling. I took the "slabs" of plaster to be analysed but when I told them I had used bondcrete I was told it was not compatible.

Therefore it is best not to risk it.

The best methods are as described above.

ok .. ill stop recommending this method.