Pastering ceiling to Attic room conversion, 2 layers?

[compact]

Hi
In Greater Manchester
Boarding the bedroom ceiling to an attic conversion
Is it 1 or 2 layers of Fire resistant plasterboard?

Thanks
Stuart

 

[tony1851]

You only need one layer and it doesn't need to be Fireline.

One 9.5mm sheet will do.

 

[compact]

Ah right

I thought to allow for x number of minutes to escape a burning house, from an attic room, the 1st floor bedroom had to be 2 layers of the pink fire resistant boarding which gives 60 mins.

can't remember where I read that though

 

[tony1851]

The advice you read was given by an idiot.

EDIT.
Hold on; are you talking about the ceiling of the attic conversion, or the ceiling of a bedroom below the conversion?

 

[compact]

Ceiling of the bedroom, i.e. below the attic floor

 

[tony1851]

That's different.
That ceiling (which has effectively become a floor) needs to have 30 mins fire resistance (not 60).
This is achieved by putting glass wool quilt between the joists of your new loft floor, and boarding over at least 22mm thick. The existing ceiling itself can usually be left as it is.
The whole composite structure of existing ceiling + new loft floor generally gives 30 mins f.r.

 

[^woody^]

And what does he need to do with the insulation to stop it falling out in a fire?

 

[tony1851]

And what does he need to do with the insulation to stop it falling out in a fire?

Oh yes, sir, I'm sorry, sir, he needs to support it on steel netting stapled to the sides of the joists, sir.
I'll do my prep better next time, sir.
Can I go now, sir,?

 

[^woody^]

Don't let it happen again. You don't want a fried OP on your conscience.

You can go now, and don't forget your assignment for Monday

 

[compact]

Thanks guys

Sorry I didn't give enough details in the first place.

So I took down the ceiling and thin joists.
Put up new larger joists to take the weight and thus am putting up new plasterboard.
It was this that I thought had to be fireproof, and two layers of.

 

[tony1851]

The new floor only needs 30 mins f.r.
One layer 'Fireline' board with skim will achieve that.

 

[compact]

Thanks for all the replies
One layer of pink it is

Thanks

 

[^woody^]

One layer of standard 12.5mm board and skim achieves 1/2 hour fire resistance