Loft conversion fire door requirements

[CoolhandPete]

Loft conversion nearly finished.
New stairs match existing and will have a mains wire smoke detector.

There are three new rooms in the loft accessible via a small landing at the top of the new stairs. A study (could be used as a small bedroom), a double bedroom and a bathroom.

We thought we would need fire doors on all three new rooms to provide an exit corridor from any one of them.

All existing doors in the house are fd30 as it is a relatively new build.

The builder believes we do not need one on the bathroom as it is not a habitable room.

I have seen this habitable room rule mentioned before but surely we will not be maintaining a safe corridor for the bedroom or the study if we don't have a fire door on the bathroom?

 

[Nakajo]

Your builder is correct. Bathrooms rarely catch fire. That said, builders normally like to fit fd30 throughout so that they don't have to think about which one goes where.

 

[chappers]

yep he is correct with the proviso there isn't a gas combustible device in there such as a boiler, in which case it would a fire door

 

[JohnD]

fire doors are thick and very heavy, so they feel substantial which gives an impression of quality.

they are also very good at muffling noise (parp)

 

[CoolhandPete]

Thanks for all the replies.
I think we have a consensus.

 

[tony1851]

If the wall between the bedroom and bathroom is not fire resistant to 30 mins (which is likely to be the case) there would need to be a 30min door on the bathroom.

 

[Nakajo]

No there wouldn't. The fire would just burn through the f@&£-/; wall

 

[tony1851]

No there wouldn't. The fire would just burn through the f@&£-/; wall

...........and once through the f@&£-/; wall, smoke would quickly come through the bathroom door into the staircase enclosure. Remember the pics of Grenfell Tower, where all internal partitions were burnt away, despite the fire coming from the outside.

 

[freddiemercurystwin]

...........and once through the f@&£-/; wall, smoke would quickly come through the bathroom door into the staircase enclosure. Remember the pics of Grenfell Tower, where all internal partitions were burnt away, despite the fire coming from the outside.

If the occupants are awoken by the alarms they will have escaped long before thats an issue and a Grenfell Tower analogy here is absurd.

 

[^woody^]

If the wall between the bedroom and bathroom is not fire resistant to 30 mins (which is likely to be the case) there would need to be a 30min door on the bathroom.

Why wouldn't the wall have at least 30 minutes fire resistance. What do you think they would have built it of, and why would it be different to the 30 minute walls they would have built on the protected hall/landing

Btw, the requirement for fire doors is 20 minute fire door sets, not 30 minute fire doors.

 

[Nakajo]

That's true, but no one actually makes a 20 minute door.

 

[^woody^]

Don't come here with your technicalities.

 

[tony1851]

Why wouldn't the wall have at least 30 minutes fire resistance. What do you think they would have built it of, and why would it be different to the 30 minute walls they would have built on the protected hall/landing

Btw, the requirement for fire doors is 20 minute fire door sets, not 30 minute fire doors.

The modern Part B gives little guidance on what spec is required for a stud partition to give 30 mins F.R. However, looking through my old 1851 edition of the regs, it does indeed state that a stud wall with 1/2" plasterboard and skim both sides would provide 30 minutes, ergo I stand corrected.

 

[^woody^]

Any stud partition, boarded and skimmed both sides will have a notional 30 minutes, even if it's not to the full technical spec.

 

[CoolhandPete]

This has all been very helpful.
Thank you all very much.

And half of the wall on the bathroom side has 12mm Hardiebacker so hopefully that's going to help with fire retarding too.