Is my barn roof strong enough to support plasterboard

[cactus head]

Hello,

I have a barn, single layer brick, which I plan to insulate with timber stud frames and celotex, and then plasterboard.
One end it brick right up to the roof, the other is a large doorway and wooden structure.
It has a pitched roof, and I plan to celotex between the existing rafters, and then was going to plasterboard over the top. The roof is timber framed, and tiled with clay tiles. It is over 100 years old. The roof is in a good condition but it has now dawned on me after realising how heavy plasterboard is (I went for 12mm thick) that I'm not sure if the roof is strong enough.

Without paying a structural engineer - how can I work this out?

Thanks in advance

 

[tony1851]

That roof would be OK to support insulation and plasterboard.

 

[cactus head]

That roof would be OK to support insulation and plasterboard.

ok thanks. I realise that my question is a based on unqualified weights/dimensions, but is there any kind of calculation I can do rather than just assume it is strong enough?

Thanks for your reply.

 

[tony1851]

Where to start!!!
If you are concerned about it (which you really needn't be) you would be best speaking with an SE and getting them to do some number crunching for you.
Sure, it would cost, but to do it yourself might require a considerable input of your own time, and would it be worth it?