plasterboarding a ceiling in the eaves

[joel10]

I have a small room that is 3m long by 2m wide. It is in the eaves of the house so 0.5m is a flat ceiling, while the other 1.5m slopes at a 45 degree angle. The plaster and lathe ceiling is already split near the joint between the two halves and the ceiling is very uneven where it has come away from the joints in places.

If I was to replace it with plasterboard, is there any way I can create a flexible join between the two halves of the ceiling, given it would need some sort of skim coating?

I have thought of putting further screws in the joists to minimise movement and then to fill any cracks that appear in the skim coat with a flexible filler.

Thanks

 

[noseall]

Once the boards have been screwed, the joints taped (scrimmed) and the ceiling plastered, complete with a filled 'roll' at the change of direction, then all should be ok.

You may want to consider some celotex or kingspan insulation within the rake space too. It may mean tacking additional thickening strips to the rafters in order to get the correct depth and air gap, but it may be worth it.

Few old properties, with raked ceilings will have anything like the required amount of insulation within the rake. This is a notorious 'cold spot'.

 

[roughcaster]

I agree with Noseall with the plastered "roll" where the flat ceiling meets the slope, looks much nicer too..... I would scrim along that joint as he said,,, but also "across" it,,, bringing the scrim up the slope, and onto the flat of the ceiling. 12" lengths of scrim,, 6" on the slope, 6" onto the ceiling, and then plastered over (rolled),,, with a strong, double re-inforced joint, underneath the plaster.

Roughcaster.

 

[marshman]

just the joint for the jute scrim

 

[noseall]

Tip: It helps, when trying to achieve a 'roll' , by applying some bonding to the junction first in order to pre-thicken and shape the curve.

Over thickening with skim can lead to an unpredictable curve and also lead to you dragging skim away from the lead of the curve. This is because it becomes difficult to lay material off the trowel at this particular junction. The suction in the bonding can overcome this problem.

Any plasterer reading the above will know what i mean.

 

[joel10]

Thanks for all the advice