Skimming rigid insulation board,advise please!

[spanishjeff]

Great forum!

tons of info,apologies if someone has already covered this one.
I've seen a few articles on skimming rigid insulation board and see Webber have a system used for insulating externally with various coats and a reinforcing mesh.
This is purely internal on a vaulted ceiling,my question is how and what products eg:can I just skrim tape the seams an over the fixings like conventional plasterboard skim?Or do I need a full mesh?

Can I skim without treating the boards in any way?egva etc.

What product to skim with?Im in northern spain so its white plaster skim here(plaster of paris and something else,slower drying than gymsum based and softer when set)most of webbers products are available here too and thats about it.

Cheers all

Spanishjeff

 

[warriorupnorth]

Firstly welcome to the forum,
Am assuming that plasterboard cannot be fixed over this for some reason, and you don't have acces to bonding , if that's the case then use webers base rend and mesh and just sponge finish the base render you might find this smooth enough to paint if you time it right, can't really think of owt else to many variables and supposition , without seeing it.
Try sticking some pics up

 

[irish_spread]

Good thinking Warriour. Stick some nice pictures on it

 

[del]

Could he not use a bonding agent ?. then skim......he also says it's internal, not external.

 

[warriorupnorth]

Could he not use a bonding agent ?. then skim......he also says it's internal, not external.

Who knows mate , possibly. Too many variables, type of board, amount of support n fixings etc etc

 

[spanishjeff]

Great stuff thanks for all the replies!

I am currently putting up the framework to mount the insulation board it will be 300 mm spaced, 30mm by 40mm laths rigidly mounted to the underside of the roof structure.
The insulation board will be 30 mm "blue board".
I'm trying to avoid adding weight to the overall roof structure its 200+ years old and in great condition,however its spanish!!And the slate here is really thick,If I have no other option I will board with 10 mm plasterboard and tape and skim it.
But my question really arises from seeing a few examples of people skimming directly onto insulation board,am I making life more difficult for myself?
Also suffering from the dreaded "Tennis elbow"a scar from skimming a large ceiling a few years ago,any remedies?

Many thanks

Jeff

 

[lucius]

Are you talking about insulation backed plasterboard if so just tape and joint it or are you talking about some kind of cement board.

 

[spanishjeff]

Its XPS(extruded polystyrene board 30 mm) its normally light blue or pink in colour and can come with a tongue and groove edge.Its not insulation backed plasterboard just insulation board.
I have seen on the net and read a few articles on skimming directly onto this product.There was one example of a victorian terrace in a conservation area in london being internally insulated and then skimmed directly over the insulation board.
I'm trying to keep from adding weight to the roofing structure(its structurally sound but 200 years old).

 

[lucius]

Iused it in my kitchen in Spain in between beams, two coated with mesh in first coat used machine plaster, no probs.

 

[warriorupnorth]

Its XPS(extruded polystyrene board 30 mm) its normally light blue or pink in colour and can come with a tongue and groove edge.Its not insulation backed plasterboard just insulation board.
I have seen on the net and read a few articles on skimming directly onto this product.There was one example of a victorian terrace in a conservation area in london being internally insulated and then skimmed directly over the insulation board.
I'm trying to keep from adding weight to the roofing structure(its structurally sound but 200 years old).

Then skim it , let us know how it goes !!