Suspended ceilings in escape routes.

[AndyF]

I have a couple of questions about false/suspended ceilings in escape routes.  Regarding a 30 min protected escape route, how can you tell if a suspended ceiling is FR30? and if it is, why would you need to check above for a breach from, for example, a room off the corridor into the corridor? (with this room also having a FR SC) I've added the picture for clarity and the space above the ceiling is less than 800mm. Any info on suspended ceilings would be helpful, TIA.

[AnthonyB]

Most suspended ceiling systems are not fire resisting so unless there is evidence beyond reasonable doubt that it is you check above for the required fire resisting construction.

[AndyF]

On 13/03/2023 at 21:16, AnthonyB said:

Most suspended ceiling systems are not fire resisting so unless there is evidence beyond reasonable doubt that it is you check above for the required fire resisting construction.

 

Perhaps the suspended ceiling is covered in B2 of ABD, fire spread linings, class 0, 1 etc. I'll have a look.

 

 

[Mike North]

A fire rated suspended ceiling will normally be positively fasten into the grid, this is no guarantee of the fire rating, the OEMs should be consulted. 

[AndyF]

Thank you.  So, in the illustration, the suspended ceiling does not form part of the 30 minute corridor, however, it is likely to be class 0 as regards to a fire spreading lining? could we say? 

[Lyledunn]

Why would you want 30min fire resisting false ceilings in the accommodation or the protected route? The floor above should be appropriately protected from immediately below the underside with all services run within the same compartment as the accommodation. To do otherwise would require service penetrations into the accommodation from the void to have the same fire resistance as that required by the floor. As is often the case, the services will use the void above the corridor and tee off to the accommodation through the cavity barriers thus requiring the openings to be maintained at 30min. 
Irrespective of the fire resistance of the ceilings, unless the walls of the protected corridor go to the underside of the storey floor above, cavity barriers will be required. Their integrity must be maintained where services pass through otherwise they may as well not be there and any service penetration of the false ceiling in the protected corridor would compromise the corridor. 
I have seen these so-called fire resisting ceilings installed as a quick fix only to find that soon after installation the tiles have been removed or hold down clips discarded. Poor design in my estimation! 
 

[AndyF]

On 15/03/2023 at 22:08, Lyledunn said:

Why would you want 30min fire resisting false ceilings in the accommodation or the protected route? The floor above should be appropriately protected from immediately below the underside with all services run within the same compartment as the accommodation. To do otherwise would require service penetrations into the accommodation from the void to have the same fire resistance as that required by the floor. As is often the case, the services will use the void above the corridor and tee off to the accommodation through the cavity barriers thus requiring the openings to be maintained at 30min. 
Irrespective of the fire resistance of the ceilings, unless the walls of the protected corridor go to the underside of the storey floor above, cavity barriers will be required. Their integrity must be maintained where services pass through otherwise they may as well not be there and any service penetration of the false ceiling in the protected corridor would compromise the corridor. 
I have seen these so-called fire resisting ceilings installed as a quick fix only to find that soon after installation the tiles have been removed or hold down clips discarded. Poor design in my estimation! 
 

Thanks for the response. I didn't make myself clear, the example I saw was not accommodation, and did indeed have service penetrations from the room into the corridor, only noticed when a tile was lifted. My concern with the suspended ceiling is/was, if there's a fire in the corridor, how will the suspended ceiling react? potentially it could collapse. What do you think? 

[Lyledunn]

The corridor is the thing being protected not the accommodation. There may be ignition sources in the corridor, such as electrical services but there should be no fire load that would compromise the route. There would be no reason to have a suspended ceiling in the corridor lest it provides protection to the floor above in which case no services should be brought through it. 
 

[AndyF]

There may be no reason for the suspended ceiling, but there are many in protected corridors, hence the question.