Fire spread/ garage to house.

[Russell griffiths]

Hi, can anybody offer any comments on my rather poor sketch

i have an attached garage on an icf build we are currently working on

at the end of the garage is a gable wall, on the other side of the gable wall is a bedroom

so looking at the sketch we have a solid concrete wall running up to the underside of the roof covering, the top of the wall will be covered in rockwool insulation 

my question. Is there a risk of fire traveling along the roof battens, should the battens be stopped in The middle of the wall and some sort of fire stop installed between the batten ends. 

Hope that makes sense. Black things are rafters

blue shaded thing is the top of the wall

red lines roof battens 

[scottishjohn]

my rememberance of garage attached to house is full fire protection+vapour protection to house

so will need alot more than that .

will be double or triple layers of drywall fire board on ceiling and smoke barrier 

might be easier to build up divining wall  like you would if it was join to another house sharing loft

floor of garage must be lower then house to stop petrol on fire running in in you have a door +that will need to be fire proof --if you get mean BC 

go check regs

Edited January 6, 2019 by scottishjohn

[Russell griffiths]

Ceiling will be double boarded, with a vapour barrier 

i had thought of comparing it to two separate dwellings

what would a detail be for two separate dwellings ? If they shared the same roof covering, like a pair of semi detached houses. 

[Mr Punter]

In reality if you have rockwool above the dividing wall compressed by the battens, fire will not travel along the battens.  Make sure there is no free air space, as air is what fire likes.

[Russell griffiths]

if You look at this pic for two separate dwellings it shows a fire stop under the breather membrane and over the top, but the tile  battens are still bridging over that area. 

Seems a bit pointless doesn’t it

or do they think the spread along a batten is very small. 

 

What ya reckon. @Mr Punter

Edited January 6, 2019 by Russell griffiths

[Declan52]

Could you use a small length of plastic batten just on this area??? 

[ADLIan]

Normally plastic = combustible! Above details look ok and in accordance with appr doc B.

[Mr Punter]

It won't hurt to put a bit of rockwool in there but if you have a 1 hour ceiling I don't think it is crucial.  You can get the stuff in a plastic sleeve and you can run the battens over which holds it in place.  Often you get living space above garages anyway.  Fit a smoke or heat detector in the garage interlinked to the house.  Actually, fit a smoke detector in every room (heat in kitchen), as the most important thing if a fire breaks out is that everyone escapes unhurt.

[ProDave]

Surely the double plasterboard ceiling and walls is the fire barrier?

 

Between our garage and the (plant) room above it the fire barrier is just the double plasterboard ceiling.

[Russell griffiths]

Cool thing I have this covered, will show bc that drawing and ask for comments. 

??