firewall requires 2 zones per floor?

[skdesigner]

Hoping the canucks can weigh in on this one in regards to the NBC...

I've run into a situation where a 2H firewall has been built in a 13R occupancy, presumably for the architect to gain an area credit. The plans reviewer has told me I need to annunciate on both sides of the firewall, even though it is the same floor. Knowing that firewalls separate into two buildings, it does make sense, but seems like overkill.

Any thoughts/past experience?

 

[cdafd]

What do you mean annunciate on both sides????

Were you going to put audio through out anyway??

 

[skdesigner]

sorry,

annunciate sprinkler zones via flow switch,

i.e I now require 2 zone control manifolds per floor instead of one...

I've never done it, and no fitter at my company ever remembers rigging it up that way. Just want to catch it in design rather than final acceptance.

 

[cdafd]

Then my reply would provide a copy of the code section so I can review what it actually says

 

[o0k7x]

Have a look at NBC Article 3.2.4.8.

If it is actually a firewall and not a 2 hr fire separation these are technically two separate buildings. This article requires that the fire alarm annunciation (by sprinklers)be by floor area.

The NBC definition of floor area is related to the actual "building" footprint.

 

[skdesigner]

o0k7x, that's exactly what I referenced.

I was told that two different buildings require two different sprinkler zones. Makes sense, again, overkill.

I've heard that sprinkler contractor's here in SK have had to do it after the fact, after missing it in the design stage.

Can't seem to find anything black and white in part 3 of the NBC, so it looks like I'll have to absorb the cost and be smarter next time.

Have you run into anything like this before?

 

[stookeyfpe]

Its not always overkill. When I was a firefighter, I can remember several incidents where we responded to a building which was divided by fire walls and spent time playing "where's the water flow alarm." I doubt if this will be the problem since this a residential building, but in commercial buildings, it can really slow the response.

 

[rmae]

Agreed.

Separate buildings as defined by the NBC absolutely requires zoning sprinkler and fire alarm zoning regardless. Always be cognizant of the standpoint of the fire fighter who is responding to a fire situation which is the main reason for zoning. If a sprinkler system has controlled a fire in one area, the fire fighters want to shut it down to allow the residual pressure to be available for another potential fire area. Also, always remember as prudent designers to locate the zone valves in accessible places such as fire separated exit stairways. Pretty hard to find a zone valve above a t-bar ceiling in a corridor full of smoke with ceiling temperatures hitting 200 degrees Celsius.

R M Arsenault Engineering Inc.

http://www.rmae.ca

 

[pipesnpumps]

I agree with you RMAE, on the location of the zone control valves.. I wish the Appendix language on preferred locations of zone control valves were firmed up into mandatory language with exceptions allowed by the AHJ. They should really be in a stair tower, outside PIV, or wall posts. I would even prefer it in a mechanical room with direct access to the exterior.

As a plans reviewer it concerns me that I can't enforce that, and the contractors are free put the riser and control valve basically anywhere.. In some cases making it completely unavailable to the fire service if there is a fire in adjacent spaces.

Oh well, I'm sure there is a good reason this hasn't been done by the 13 committee. Perhaps it is because it is very rare that a control valve would need to be shut during a fire, or that it would only need to be shut after the fire is well controlled or extinguished.. And by that time they would be able to access it.