Retrospective noggin installation in ceiling

[diynovice99]

Posted to the plastering forum but with no response, so I was hoping I might be luckier here... Thanks in advance!

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!



Read more: https://www.diynot.com/diy/threads/noggins-for-ceiling-plasterboards.573613/#ixzz6zFg5qsMY

 

[Deluks]

Fiddly but doable. 3x2 would work. Obviously you'd need to get the whole ceiling reskimmed.

 

[SFK]

Why not put up new boards over the old ones?
Off setting the edges of course.
SFK

 

[diynovice99]

Fiddly but doable. 3x2 would work. Obviously you'd need to get the whole ceiling reskimmed.

Thanks, Deluks.

 

[diynovice99]

Why not put up new boards over the old ones?
Off setting the edges of course.
SFK

Hi SFK,
Would this not still require the insertion of noggins, or are you thinking 15mm boards? If the latter, I guess I just need a spare back to get them up
Thanks.

 

[cdbe]

Cut some slots with a multitool, insert strips of thin (6mm) plywood with string through at each end, pull down and screw through both boards into ply, fill gap with bonding and scrim tape. It's not so much noggins that are needed but something to tie the unfixed edges to each other.

 

[SFK]

Yep - sorry - spare or new back needed.

Yes, put up new boards over top of old ones to cover whole ceiling.
With new boards overlapping old, so joints staggered.

No need for noggins as the orginal sheets will support the joints of the new sheet.

Long PBoard screws though both sheets into joists.
Shorter PBoard screws though both sheets near joins (and everywhere else to make truely strong).

SFK

 

[jeds]

Fitting noggins from below will be an ordeal. SFKs suggestion will be less work and provide a better finish. Double board with staggered joints, re-skim, job done.

 

[diynovice99]

Thanks all for the really helpful replies. Seems like retrospective adding noggins would be a real headache and thus I have the option of either over-boarding or putting joining strips of, say, hardboard, behind the boards to stich the edges together. Do you think they will both produce a decent quality, crack-free finish? And in the case of overboarding, to help my back a bit, am I right in saying I can use 9mm board?

Thanks again!

 

[^woody^]

Just overboard with 9mm 6x3, longest length spanning across the joists. Phosphate screws at max 200mm spacing, a bead of tube adhesive among the back of the [short edge] joints that don't land on a joist.

 

[diynovice99]

Hi all,
I've followed the majority opinion and ordered 14 sheets of 9mm 1.8 by 90cm. I'm hoping they are fairly manageable by one man and a prop.

Thanks for all your help!