Pre-insulated plastedboard for flat ceiling

[wexford dude]

Hi,

A simple question.I am currently looking at a small project where the ceilings are going to be re-done with pre-insulated plasterboard.There is 12.5mm foil back already in place.There is no mention of a fire-rating for these pre-insulated plasterboards.Foil back plasterboard has a 0.5 hr fire-rating if memory serves me correct.Whenever I have done a timber ceiling there was always foil back plasterboard put on first for fire-rating purposes.I have no issue taking off the original plasterboard I am just curious if the modern plasterboard has any built in fire-rating.

Cheers,
Wex Dude.

 

[Toto]

1 x 12.5mm foil back = 30 min
2 x 12.5mm plasterboard = 30 min

The vast majority of thermalboards are a 12.5mm plasterboard lined with various specs/thicknesses of insulation. Based on the above you would not even get a 30min fire rating with a thermal board, unless you overboarded the existing foil backed board.

Although, I seem to remember seeing a foil backed thermal board somewhere, whcih would retained your 30 min fire rating on its own.