Insulating an exposed beam ceiling

[Pinoy]

Hello.
Our lounge has no roof insulation. Its cold. There is no loft.
The most straightforward way is to add insulation between the beams, see pictures.
The beam thickness is 15cm. Between the beams is plasterboard.
I want to DIY this so am looking at advice on how to do this.
I want to use thermal insulation panels due to their high R rather than rockwool for example.
This stuff has an R of 4.65 for 103 mm thickness.

https://www.recticelinsulation.com/fr/fitforall

Can I glue these to the existing plasterboard ?

I intend to add a false ceiling below the panels…maybe something like this

https://www.dumaplast.com/fr/applications/panneaux-plafond-decoratifs-pvc


Any advice ?
Thanks in advance.

 

[JohnD]

do you want to retain the beamed effect?

or to have a flat plastered ceiling?

what is above the beams?

both PVC and foam slabs are flammable and emit poisonous fumes in a fire.

Plasterboard forms a fire barrier.

mineral wool is non-flammable

 

[Pinoy]

Hi John thanks for the reply.

Yes want to keep the beams…above plasterboard are roman tiles like this..traditional technique in this part of France..our roof is exactly like this
https://www.lemoniteur.fr/article/couverture-en-tuiles-canal-comment-ca-marche.1380604


And yes you’re right…just read the datasheet on those panels, they recommend plasterboard for fire resistance..
“Fitforall doit être revêtu d'un parement assurant la protection au feu de l'isolant (exemple : plaque de plâtre BA 13)”…..as you can guess plaque de plâtre is plasterboard…

 

[Mr Chibs]

You could fix foam boards (twice as efficient as rock wool) or rock wool into your current plasterboard areas and secure.

If using rock wool secure with mesh, or wire zigzagged and stapled from being to beam, keeping it in place.

Then you could buy 2x1” (or bigger) batten at 400mm centres... Run at 90° To the beams, then plasterboard, you can then skim Or whatever.

Where in France, if it’s somewhere I like, I probably won’t talk to you again. Hahaha