Wall to Cathedral ceiling plaster

[OBBob]

Hi All

When a plasterer is plastering a room with cathedral ceilings, would they run the long edge of a sheet along the join between the wall and ceiling joint and fill ... or would they score the back of a sheet and fold the sheet to make the joint so that the sheet ende up half on the wall and half on the ceiling?

Based on plaster sheets comign in 1200 or 1350 widths ... I am just trying to work out how best to layout my room to avoid too much wastage.

[pawnhead]

I've seen them do that, and I've done it myself. You'd have to be careful and accurate, and I usually end up just cutting the corner where it looks dodgy and plastering it as you'd normally do.
With preformed, manufactured bulkheads, they V groove the back of the sheet and fold it to give an outside corner without breaking the paper, or installing an external angle. I've tried that with my router and it works OK, but of course it has to be high up so the corner doesn't get knocked or damaged.

[OBBob]

Great ... thanks pawnhead, that should help.

[rod@plasterbrok]

Hi the preformed bulhead is not an option in this instance.

Cut and fold on cathederal ceilings is definitly the best way to go if you get it right. To go into all the details here on the tricks to get it right is too long. I have 4 page web page drafted to tackle this very issue. But it won't be published for a while yet. The main point is as Pawnhead says is accuracy when measuring and cutting. If you get it to come off ok it looks great. However their are many contibuting factors in that can make it go pear shaped. If your frame is straight you are 1/2 way home.

If the fold does not work, don't worry, it normally leaves you with a tight join to fix a metal angle and stop up like normal.

Give it a go, cut a test piece first to get the right measurement, and go from there. It is best to have at least 300mm of the fold running up the ceiling, as opposed to 300mm running down the wall. This helps you control the positioning and snapping of the sheet.

Don't be too concerned about the join falling on a batten. In fact it is better that it falls between the battens. Then use 300mm lenghts of batten as cleats screwed along the join at 450 centers fixed at right angles to the join.

Trying to get it to fall on the batten can be a pain if it just misses or doesn't leave enough batten showing to fix the next sheet. It saves a lot of mucking about just to set it up to fall between the battens as described.

Hope this helps a bit I know it is all a bit sketchy.

Cheers Rod

[pawnhead]

Hi the preformed bulhead is not an option in this instance. Yeh, I was just mentioning that for interest sake.

You're the expert at plasterboard, and I haven't had that much success at the cut and fold method in the past. It's worth a go though since you can always just cut it and set it as per usual.

I've found that it's best not to nail too close to the corner. Just put big blobs of glue there and keep your nailing or screwing back a couple of hundred mm.

Of course Rod would know the best methods for the best results.

[rod@plasterbrok]

You are correct, I forgot to mention not to nail near the fold at least 300mm back. And lots of glue right on the intersecting point.

There is so much information on the technique for getting a successful cut and fold. But in reality it is very easy, if you do it right. When I started drafting the page for my web site I thought this won't take long. But when I started thinking about all the methods I use to conteract framing that is not straight either on the wall or ceiling, different framing directions etc, it ran into pages of information and may diagrams.

We used pre formed bulkheads to do many of the bulkheads in South Lands shopping center in the 1980's, this was the first time we had tried them. We made them on site using a router paper tape on the back with pva glue. They worked great in that application.

I find it difficult though, to justify their use in a domestic situation where the quantities are not that great.

One of the issues with them, that I see often is the butt joints created when installing them are not finished off correctly.

The other problem is the cost v's other methods. No plasterboard supplier keeps them in stock and they are made to order, creating further delivery costs. In the right application they can save a lot of money and fiished off right, look great. Mainly comercial applications.

Cheers Rod