Fire regs for exposed timber ceiling joists

[Pelena]

Hi- we are refurbishing a flat and want to out insulation and plaster board between e ceiling joists in the lower ground floor of a victorian property as it makes a massive difference to ceiling height. Any ideas on what to use to meet fire regs, as we'd have exposed timber? Thanks!

 

[tony1851]

You would need 60mins fire resistance, which would be almost impossible with exposed timber beams unless there was some magic proprietory coating you could find.
And what about sound insulation???

 

[Pelena]

You would need 60mins fire resistance, which would be almost impossible with exposed timber beams unless there was some magic proprietory coating you could find.
And what about sound insulation???

We will have insulation - we are only exposing part of the joists so will put insulation between the floor and the plasterboard. The joists are quite deep, and the floor above is part of my flat.
Seeing there are plenty of flats with exposed beams, am wondering whether they all predate fire regs? Pretty sure the original ceiling in my place was exposed too

( also putting an extra layer of ply board between the joists to help with sound)

(Eta: and thanks for taking the trouble to reply! )

 

[luisdesign]

It sounds like the work you are doing is notifiable, do you have a building control officer on hand?

You can get fire resistant and retardant paints, but these are usually for steels.

 

[Pelena]

It sounds like the work you are doing is notifiable, do you have a building control officer on hand?

You can get fire resistant and retardant paints, but these are usually for steels.

The reason we need building regs is that part of the project was structural, so we need a certificate of completion for the lot (the structural issues are all sorted). We have a bc officer but he is incredibly over zealous (my structural engineer says he has never come across someone quite so picky- he demanded detailed plans of the flat above (the house is a two flat one) for a pretty straightforward kitchen/sitting room knock through for example so want to do my research first)..... I will look look into paints, thanks

 

[maltaron]

I am always amazed with the opinion that timber beams are a fire hazard. Whenever you see a burnt out building the steel work is bent and twisted but the timber beams are charred but still structurally sound. The charring is fire retardant.

 

[Pelena]

I am always amazed with the opinion that timber beams are a fire hazard. Whenever you see a burnt out building the steel work is bent and twisted but the timber beams are charred but still structurally sound. The charring is fire retardant.

I couldn't agree with you more

 

[OwainDIYer]

We have a bc officer but he is incredibly over zealous (my structural engineer says he has never come across someone quite so picky- he demanded detailed plans of the flat above (the house is a two flat one) for a pretty straightforward kitchen/sitting room knock through for example

And how else is he going to verify that the loadings on any beams have been calculated correctly if he doesn't know what the beam is supporting?

 

[tony1851]

I am always amazed with the opinion that timber beams are a fire hazard. Whenever you see a burnt out building the steel work is bent and twisted but the timber beams are charred but still structurally sound. The charring is fire retardant.

That is true, particularly for larger sections of timber. However, in this context it is not the whole story.
As well as an adequate period of fire resistance, the ceiling also has to comply with surface-spread-of-flame requirements, which is not the same as fire resistance.
Fire can spread rapidly across untreated timber surfaces without necessarily impacting on the fire resistance of the floor.