Swapping internal door casings to fire rated

[Ian H]

I have to do this to 6 doors as part of a loft conversion. I knew I had to have 30 minute doors but never thought of the casings.

I just had a look at some in the builders merchants, they are a good 1" thicker than mine.

Am I going to have to have 2" smaller doors? The casings at the minute would fit a 762mm door.

Could I retro fit the intumescent strips to my existing casings or would that be like painting normal plaster board pink and calling it fire rated?

Cheers

 

[freddiemercurystwin]

Why do you need to change the frames normally just the doors can be changed.

 

[Ian H]

That's what the BCO has told us.

All the bedrooms, the bathroom and 2 doors into living rooms at the bottom of the stairs.

 

[Gerrydelasel]

That wasn't the case here in Burnley. Only the doors needed to be changed here.

 

[Ian H]

Would this be written down somewhere? He also said my beam calcs need the authors name and qualification on and I've been told that's not true either.

I wonder if he goes drinking with the guy that drew the plans? We fell out.

 

[Deleted member 174758]

That wasn't the case here in Burnley. Only the doors needed to be changed here.

To quote from the BWF Certifire website (link supplied, OP):

"The practice of ‘knocking up’ a door frame on site or in a workshop, hanging a door and believing that the result constituted a valid fire door installation was never correct."

and

"Door frames should be purchased from the door manufacture, or from a company licensed to manufacture them or via a BWF Approved Fire Door Centre.

• 60 minute fire doors - Frames should be made of hardwood with a density greater than 650 kg/m
• 30 minute fire doors– frames or linings can be made of softwood, with a minimum density of 450 kg/m3 (or to match the density and frame dimensions given in the manufacturers’ installation instructions)"

as well as:

"How thick should my fire door frame or lining be?

Frame or lining thickness would usually be tested at a minimum 30 mm (finished size, excluding stops) or the thickness given in the manufacturers’ installation instructions, to ensure hinge screws hold securely"

On commercial jobs we are now required to install rated door casings from a licensed workshop (our main joinery supplier is certified for the frames), they must be sealed around the frames with AFFF (pink) fire foam and then a layer of intumescent fire stopping applied beneath the architraves. For insurance purposes we are required to photograph each and every door casing now (which can be a royal PIA). This is a fairly recent change, but BCOs do appear to be tightening their application of the standards, so what applied say 2 years ago doesn't necessarilly apply today. It is quite possible, therefore, that the OP's BCO is a bit more up to date, or a bit more rigid (some of them are a nightmare). AFAIK if the door casings are under spec. then BCOs have always been at liberty to refuse to pass them, although I've rarely experienced it myself

 

[^woody^]

Minimum 30mm thick