Rob Convery wrote:

A pic of what I am looking to do is at
http://www.convery.me.uk/temp/ChimneyBreast.jpg (Red = addition)

The other option would be to use taper edge plasterboard and then scrim
and fill the joint. Once sanded flat you can get a supprisingly good finish.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/