Advice on upgrading insulation of vaulted ceiling

[FozzieBear]

Thank you all for your help and advice. My main concern was creating a vapour trap by overboarding the existing ceiling that has an impermeable vapour barrier under the plasterboard. This construction was done in 2000 and complied with building regs standards at that time but I wanted to further increase Uvalue at same time as getting rid of artex finish. Thanks again.

 

[catlad]

My main concern was creating a vapour trap by overboarding the existing ceiling that has an impermeable vapour barrier under the plasterboard.

Then start from scratch.

 

[Ivor Windybottom]

Anything you do will be a compromise. You don't want to lose much height as it's vaulted. Only you will know what would or wouldn't be reasonable.

As it was done in 2000 it should already be pretty good. It probably just needs the minimum. Don't worry about creating a sealed space, that is only the same as every wall cavity and double glazed window. There should be a membrane as close as possible to the interior space. Often foil-backed plasterboard is the easiest way of achieving this.

If you don't have issues with cold or condensation then you could just have it plastered over. This is the standard answer for artex, plasterers do it regularly and it's not a problem. Our kitchen ceiling was like the surface of the moon with spiky artex, now it looks like the place was built yesterday and is perfectly smooth. No cracks or issues at all.