Stage Smoke Control

[peach]

IBC (and IFC) say essentiall this regarding smoke control for a stage (let's assume the fire curtain isn't required, because in this case it isn't - stage height < 50'). 2 smoke vents are installed on the roof; 410.3.7.1 requires automatic opening by approved heat activated devices (done - fusible links). Supplemental means shall be4 provided for manual operation (also done.. latches located on the roof).

We tested using smoke bombs on the floor and gave the contractor 2 minutes to get on the roof. Even before the vents were opened, the smoke layer rose above 7' (good). Smoke did, however escape into the auditorium.. maybe not so good.

Since it's a mechanical system, there is no control from the fire control room.

While it seems to satisfy code minimums, having the manual release on the roof doesn't make much sense to me. Can anyone explain the reasoning?

On a side note, has anyone looked at the requirements of 909.18.8.2 for special inspection requirements for inspecting smoke control systems? Code is saying certification as an air balancer.. that's a whole other topic.

 

[cda]

I would say because if inside and the fire was on the stage, the firefighters would not have to go inside?

Where is on the roof required?

410.3.7.1 Roof vents.

Two or more vents constructed to open automatically by approved heat-activated devices and with an aggregate clear opening area of not less than 5 percent of the area of the stage shall be located near the center and above the highest part of the stage area. Supplemental means shall be provided for manual operation of the ventilator. Curbs shall be provided as required for skylights in Section 2610.2. Vents shall be labeled.

 

[peach]

Code doesn't say... the vents are 40' up.. the links aren't going to melt until the collected smoke is hot enough. I'd like to see the control at the stage or control room. I can't find the verbiage to require it.

Chances are, I suppose the fire may be more likely to start in the fly gallery and not the stage..

 

[cda]

Similar to the old days with high piled stock vents.

I saw a lot of different set ups for manual release both inside and out.

An ahj could do an amendment as to where they want the release

 

[peach]

probably too late for amendments for this Code cycle.... it's a complicated process here (Congress gets involved).

 

[steveray]

Most of ours have a cable and pulley system that activates from the floor nearby....I would push for that and if it is workable from the roof as well....great.....

 

[AegisFPE]

I am confused - 410.3.7 says comply with 410.3.7.1 or 410.3.7.2.

410.3.7.1 is prescriptive and should not require a special inspection or performance test.

Also, there seems to be some consistent interpretation in the ICC Community that the referenced manual release is to be accessible from the stage level.

410.3.7.2 is a smoke control system in accordance with Section 909.

In such case, the design should have been prepared in accordance with 909.2 and a special inspection testing plan should have been submitted as a part of the design submittal per 909.3. I would be skeptical of a special inspection plan that relied upon visual observation of a "smoke bomb" test due to the lack of correlation between such characteristics as the rate of smoke production, density and color of smoke particles, temperature and buoyancy of smoke, etc.

 

[cda]

410.3.7.1 is prescriptive and should not require a special inspection or performance test.

Also, there seems to be some consistent interpretation in the ICC Community that the referenced manual release is to be accessible from the stage level.

I have seen a handle at various levels inside and out mainly on high pile stock

 

[peach]

Well then the consistent interpretation in the ICC community needs to get to the design community.