Roof rafter noggins for plasterboard ceiling

[jhg68]

Hi all

Looking for some advice on the number of timber noggins required for roof rafters at ceiling level.

I have removed the existing plasterboard ceiling in a large room that had areas of water damage from past leaks.

The roof rafters have no noggins at all and they are at 600mm centres.

I plan to use 12.5mm 2400x1200m plasterboard sheets for the ceiling and install them perpendicular to the run of the rafters. I will stagger the sheets as well. These will all be screwed in with black phosphate coating bugle head screws 3.5 X 38mm and screwed every 230mm.

All noggins 4x2 timber

Install noggins as follows:

- around the perimeter of the room
- at the plasterboard edges

However, as the rafters are 600mm centres I think I will need to put in additional noggins when using 12.5mm plasterboard. Not sure whether it should be every 600mm or 400mm. I think every 600mm would be ok as it will cover the edges as well as one down the middle of a 1200mm wide plasterboard. Can anyone confirm if this is ok or should I go with 400mm?

Thanks

[arco_iris]

jhg68!

IMHO, it's up to you what, probably unnecessary, extra noggins you want to put in.

With 12.5mm p/board & 600mm rafters, noggins are only really needed at the unsupported joints and I'd say that by fixing the boards "perpendicular" (at right angles?) you'll need more than if fixed longitudinally, again that's up to you. You'll need them every 1200mm, lengthways only needed every 2400mm.

Bear in mind that 1220x2440 boards would need trimming to fit 600mm centres, check - in an older property you may have 610mm centres (24 inches). That's really of little consequence though, all joints should be central to any rafter/noggin.

Do not drive the bugle heads in too far. Wipe filler over the heads before applying jointing tape. Then skim.

Also consider that if you intend to install downlighters, noggins may well get in the way.

[PaulS86]

Agree with all advice above.

However, the one ceiling I did not noggin has cracked....

I have used noggins on every single ceiling done since, and not one crack. For the small amount of time it takes I would add them as you have descirbed.