Ceiling repair advice

[rhodes73]

I've got a rather large hole in the ceiling from some water damage.
My first plan was to cut the plasterboard back to the nearest joist and then put up a new board to fill the gaps.

What is the best way to cut the current plasterboard along the middle of the joist? Is it just a case of a straight edge and Stanley knife?

 

[PrenticeBoyofDerry]

It would depend what tools you have to work with, but yes stanley knife and a straight cut at middle of joists.
Don't forget to measure the depth of the existing plasterboard as they do vary. Also rack off about 50mm of the plaster finish on the good board, this will allow a joint tape to cross the butted up old and new board and also allow you to blend in the plaster finish repair better/easier.