Patching advice please

[Beelzebub666]

Hello, hopefully this is quite a straightforward question - basically I'm removing a 2' by 4' approx section of lathe and plaster sloped ceiling so I can sister a damaged rafter (penetrating damp, now cured) and I will be patching the hole with plasterboard fixed to the rafters. The plaster around the hole is sound and painted.
My question is, how do the pros go about finishing a patch so it doesn't show after re-painting? A couple of articles I've seen online recommend joint compound with reinforcing tape around the edges and feathered a few inches past the hole then lightly sanded, does that sound right and can anyone expand on it?

I'm a fairly competent amateur with backing/board and finish, but this will be my first attempt at a big patch. Can I get a reasonable finish without skimming over the lot?

Appreciate any wisdom you can share.

 

[PrenticeBoyofDerry]

You can board over the area, leaving the board slightly lower than rest of the plastered area, about 3mm lower. Then remove about 50mm of the finish plaster on the good bit, around the joints. So you can then apply self adhesive tape around the joints and skim it with board or multi finish. Leaving lower will allow you to apply tapes and a double coat of finish, giving you a flat even surface.
Or again replace the board, this time coming level with the rest of the ceiling area, again remove 50mm of the finish on good plaster around the joints, apply tape and fill out with easyfill, this will take about 3 application each needed to be sanded when dry. The first application should be spread about 6-7 inch over joint, the second about 10 inch, then third about 12 inch, feathering the application out. After the third application has dried you then sand the joint down, so no lips on the edges and nice and smooth and even over joint
Then the area can be primed for painting.

http://www.wickes.co.uk/Plasterboard-Jointing-and-Repair-Tape/invt/163566

 

[Beelzebub666]

Thank you, that's very helpful.

 

[PrenticeBoyofDerry]

No problems, happy to assist.