Smoke alarm system for 3 storey flats?

[S60TEM]

Just a bit of advice really guys.

I've been asked to qoute on a smoke alarm system for 3 flats, one ground floor, one 1st floor and one on the second floor.

Now basically theyv'e asked for them in all flats plus on the communal stairwell also.

I'm thinking an LD3 grade D system with optical smoke alarms on the stairwells, interlinked together (but not into each flat and also a break glass alarm button at the bottom of the main stairwell.

Each flat again with interlinked smokes (not optical) but not linked to each individual flat and wires in RED pvc cable (T&E and 3Core&E)

Wired into each specific DB before the RCD protected circuits.

Put loads of smokes into houses and student lets but just not 3 seperate flats as such so some advice would be good.

Any thoughts guys.

 

[Andy™]

i priced a job similar to this a while back. communal building, 8 flats, 4 floors in total.

fire alarm company who looked at it went with fire alarm in all communal areas, break glass at front/back door etc, and sounders on each floor. cant remember what category though

each flat was to get their own independant smoke detector in hallway wired to the light.

so pretty much the same setup as your suggesting

 

[NozSpark]

Normally you'd put a panel alarm in the communal areas with a sounder from that into each flat and a break glass on each floor and at each exit... In each flat you could stick in a normal LD2 or LD3 system.

If you are unsure about this then I'd sub that work out (or at least the design and commissioning) as you could end up in very deep do do if you get it wrong,,, you'd also need good PI insurance as well as your PLI (with failure to perform as an added extra)

 

[Manator]

Many fire alarm suppliers offer a supply and commission service, it would be a good idea to have a chat and see if they can help you out. Each block of flats will have its own risk assessment, not all would be the same.

 

[NozSpark]

IIRC the guy that does it for me puts a detector/sounder on each change of ceiling height as well

 

[Andy™]

IIRC the guy that does it for me puts a detector/sounder on each change of ceiling height as well

voids over a certain size need their own detectors

 

[NozSpark]

[quote name='Andy

 

[Sidewinder]

The bit that Manator has put about the FRA is a good point.

The alarm system must work in conjunciton with the clients FRA as the major piece of legislation is the RRFSO.

 

[NozSpark]

And that FRA will most likely call for appropriate emergency lighting

 

[Sidewinder]

^Quite!

 

[kme]

Funny, FRA was where I was going with this....

With the last (2 storey) block of flats; we spoke at length to the regional fire officer; and ended up with communal opticals; interlinked to a heat just inside the room from which the flat opens onto the communal stairwell. Test/hush/locate switch in the hallway; and basic EM lighting.

There is always a trade-off between ideal install, and what a landlord will cough up for. The fire officer knows this; and will generally say that, if there is currently NO fire detection system, anything that is installed is an improvement over the existing!

KME

 

[Manator]

Another point worth mentioning is the level of detection the landlords insurance will insist on.I sometimes include a comment received from the regional fire safety officer, as they inspect for conformity. However I had to attend a school once because the fire officer noticed something wrong but did not know what reg it was, so even they have flaws.

 

[S60TEM]

OK, i've put my estimate in for the work and also spoke to NAPIT technical about my design which they were happy with.

ground floor flat = Interlinked Heat alarm in kitchen, Optical Smoke alarm in living room and Optical smoke alarm in hallway (escape route). Wired in Firetuff and running its own 6A RCBO protected circuit giving a grade D LD2 installation.

first floor flat = Interlinked Heat alarm in kitchen, Optical Smoke alarm in living room and bedrooms as specified by architect + Optical smoke alarm in hallway (escape route). Wired in Firetuff and running its own 6A RCBO protected circuit giving a grade D LD2 installation.

top floor flat = Optical Smoke alarm in living room / kitchenette as its one contained open plan space. Wired in Firetuff and running its own 6A RCBO protected circuit giving a grade D LD3 installation.

communal stairwell = Interlinked multi sensor alarms in lobby, first floor landing and top floor landing, break glass call points in lobby and first floor landing with manual test / hush switch. Wired in Firetuff and running its own 6A RCBO protected circuit giving a grade D LD2 installation.

All using the AICO range.

 

[kme]

The only issue I could envisage is the sound level in the bedroom of the flat from the communal escape route alarms - i.e. if the communal alarms go off on the stairwells, are they loud enough to penetrate the flat door, hallway, and any rooms between there and the bedroom, with enough SPL left to wake someone up?

Talking to NAPIT tech. is one thing, but they won`t sign the design cert. mate - I`d have spoken to the RFO too, and looked at having at least a sounder for the communal in the principal habitable room of the flats.

I like the Aico kit

 

[Manator]

The design you suggest is very basic, without seeing the building and taking measurements I would not be able to give a definite design, however if I was to do a basic risk assessment based on the limited information I would be concerned about the warning given to other residents if a fire was to break out in any of the individual flats, to address this I would want a smoke detector linked to the communal area detectors placed in the entrance area/hallways of all flats, the front doors to the flats will be fire doors, or should be, and smoke and fire penetration could take a long time.

On raising the alarm I would be concerned with the ability of the occupants to hear the alarm and take action quickly enough, to address this I would, just as KME suggested, be very keen to install internal sounders in each of the flats, linked to the output of the communal system.

Thats just a few considerations you should be making.

 

[S60TEM]

I totally agree with what you guys have said and I may suggest that each flat have a sounder from the communal alarm as the plans do state fire doors.

thanks.