Plastering of new boards inserted into existing ceiling.

[Axe]

I have a section of ceiling that needs replacing due to a previous damp problem and was wondering how to go about blending the new plaster into the old plastered part of the original ceiling.

Where the new bare plasterboard meets the edge of the existing plastered ceiling, on the existing ceiling half, should I sand a recess into the old plaster to get it level with the new plasterboard, allowing the tape to sit level, or is there a better way to go about this task?

Also, for where the new plaster will meet the old edge (the sanded-away bit in the old ceiling), should it be a stepped edge to give a hard edge to work against, or a gradual feathered edge to blend the new plaster into?

I may well end up getting someone to do the actual plastering, but I want to do all the preparation to save some money.

Thanks very much.

 

[roy c]

You would be better to get a plasterer in to do the prep and blend the old in with the new. If i have to put in new plasterboard next to old plasterboard I cut into the old board about an inch in about 4 mm deep and take that little section out with a stanley knife,then unibond it with 2-1 unibond leave it to dry so there is no suction on the old board. Then either use tapered edge board to abutt to it or do the same to the new board as you have done with the old one so the new board is level with the old board (if you have to do the same as old board then you will have to unibond this edge aswell.) Then when it gets skimmed in, this area gets scrim taped (bedded into the plaster)and feathered into match the rest of the ceiling. Ideally I do 1 inch in and use 2" scrim but if you can get it one and a half inches in or even two inches then you can use four inch scrim tape, this is better if the new joint isn't on a joist..You can put noggins in if your cut is across the lengths of the joists as opposed to on a joist... if you can understand all this and can do it then go ahead if not get a plasterer in

 

[Axe]

Thank you for your reply!

I do understand all that but I may still get a plasterer in to do it properly! I might have a go and if it comes out okay all well and good; if not then at least I can watch him and learn something!

Thanks again

 

[roy c]

Let us know how you get on with it ,Good Luck.