Noggins for ceiling plasterboards

[diynovice99]

Hi all,
I would be very grateful for any wisdom you have time to share. I have a ceiling I want to get skimmed. It was plasterboarded by the previous owner and filler applied between the boards. However, there is no securing of the long edges of the boards and thus the boards have moved independly and the filler has come out, and I imagine skim coar plaster will do the same.

The boards are 12mm and the joist spacing is 600mm. I gather, from the British Gypsum website, that for this configuration noggins should be present and secured-to under the long-edge joints. My question is, how would people approach retrospectively adding tbese? The roof is very shallow and thus it is almost impossible to work from above. The room is about 7.5m by 2.2m, so one thought is cutting maybe 3 or 4 access holes to work through from below. I'd use the unsecured edge as one side of the hole, the 2 surrounding joists as 2 others and then cut about 40cm, say, parallel to the joists. This would leave me with 2 noggins to add and a sheet of 60 by 40cm plasterboard to secure on top for each hole. And I'm hoping to be able to reach and fix noggins to adjacent joist spans from these holes. I was looking at using either 2 by 3 or even 2 by 2 wood for the noggins. Does all this sound reasonable, or is there an easier way? If I can, I'd like to avoid having to rip all the existing boards down and to dispose of them.

Thanks in advance!

 

[Bonni]

Correct, noggins should be present on 12.5mm plasterboard when on 600 centres. Joists at 600 centres should have 15mm plasterboard. So either fit noggins or overboard in 9mm, scrim tape joints and skim.

 

[diynovice99]

Correct, noggins should be present on 12.5mm plasterboard when on 600 centres. Joists at 600 centres should have 15mm plasterboard. So either fit noggins or overboard in 9mm, scrim tape joints and skim.

Thanks, Bonni. 9mm should be easier than 12 or even 15 if I overboard., so that's good to know.