Use fire resistant Plasterboard instead of fireboard ??

[MGPD]

I need 30min fire resistance on my dormer on the neighbours side.
I was told to put some superlux fireboard there on top of the ply outside, but just found out it's £133 a sheet!

There are 1hour fire resistant brands of plasterboard at around £7 a sheet.

Would that be acceptable on the inside?

Thanks

 

[tony1851]

Try 6mm Masterboard over the ply. That should give you 30 mins.

 

[MGPD]

Thanks for your reply.
That would be alot cheaper at around £35 a sheet.
But would it be necessary?
Would the fire resistant plasterboard on the inside be as effective yet cheaper and easier to install?
Regards

 

[tony1851]

Thanks for your reply.
That would be alot cheaper at around £35 a sheet.
But would it be necessary?
Would the fire resistant plasterboard on the inside be as effective yet cheaper and easier to install?
Regards

When building a dormer cheek adjacent to (but obviously above the level of) the party wall, the building inspector will usually ask for fire resistance from both sides.
This is to prevent fire fom your neighbour's house spreading to yours, as well as it spreading from you to them.
Fireline board on your side of the studs only will not achieve this, hence the Masterboard on the other side.
(If tiling the dormer cheek, I often wonder if that itself would suffice, but some inspectors I've spoken with say NO. Whether they are correct or not, I don't know).