Hi Guys,

can you clarify please.

i'm on site today wiring up door entry, CCTv and card access, sparks were completing the fire alarm, big debate breaks out between owner (good client if mine) and the sparks about a motorised hatch operation top of stairs.

this is a G2 listed building being converted from offices into 6 flats, has basement (not occupied), ground, 1st and 2nd floor, wooden stairs, common area fire alarm

Owner has checked regs and believes the roof hatch should open if the fire alarm activates, the thinking being its not a fire on the staircase, but smoke from a fire in a flat, would obscure vision of escaping residents, hatch opens to exhaust the smoke.

Sparks believes it should shut on activation (if open), otherwise it will cause a chimney effect and draw the fire up the stairs.

so who is right?

as said, its on four levels, they have used a single zone analogue panel, my understanding is floors should be separately indicated, albeit only a call point and one or two smokes per level.

no idea if they have wired the sirens alternative floors, but they have used both outputs.

tbh not overly confident because they asked if i had a spare resistor - but did not know the value (10k) to temp bridge one of the sounder outputs.

would not usually get involved, but client is a long timer, and i don't want him having expensive mistakes to put right after decorations are all done.

It's not your problem so don't get involved tbh!

It's not your problem so don't get involved tbh!

Sparks believes it should shut on activation (if open),

Moron,

Moron,

Agreed.

It should open arf, and have bgu overide normally at the bottom of the stairs.

It will make fire worse, but also gives you time to breathe and escape, i think its like two breaths of smoke and your TKO!

Most i know of open for any fire, as dictated by their fire officers RA

Agree as above.  Hatches must open if required on fire alarm. The reason is most of victims in fire are killed by smoke, not by flame, so open hatch gives smoke to escape.

 

Single zone alarm panel for these 4 SD and 2 CP in communal area is 'OK.

Thanks Guys,

I could not be sure, i was thinking when mags that hold doors open, then release on fire.

Most external fire doors remain shut to stop fire spread and to deny oxegen to the fire, so in that sense it seemed against traditional thinking to open the flap, so could see the reasons as above about smoke.

And thanks for the 'up' about separate zones not needed

Big Thanks again guys

Edited November 9, 201312 yr by arfur mo