Compartmentation

[Dinnertime Dave]

Following a visit during the construction stage of a leisure centre it has come to my attention that the compartment walls above the false ceiling on the 1st floor only have been constructed using a single layer of stone wool fire barriers. On further questioning it transpires that due to it being single thickness (incorrectly fitted) it only gives 15 minutes insulation not the 60 minutes as required by B3 of ADB.

B3 requires:-

The building shall be designed and constructed so that in the event of a fire, its stability will be maintained for a reasonable period. To inhibit the spread of fire within the building, it shall be sub-divided with fire resisting construction to an extent appropriate to the size and intended use of the building.
The guidance recommends 1 hour FR in terms of insulation and integrity for any compartment separation irrespective of the use of the rooms or space each side of the wall.

Fire consultants have argued that it meets the functional requirements based on the level of risk associated with the materials which exist on the unexposed side of the compartment wall i.e. cabling.    

The temperature on the non fire side is estimated to be 300 degrees centigrade at 60 minutes. 165 centigrade at 17 minutes

Now I understand the rationale behind the argument and in all probability the fire may be through the roof before it’s through the wall and, whilst the cabling may not burn, will it melt and fall, even if it is on trays? Potentially hampering firefighters.

We have also given the advice to contacting the insurance company – but all they ask is does it comply with the RRO?

My thoughts are that whilst carrying out an audit the omission may not have become apparent but, following a fire where the compartment wall may have failed and potentially injuring or worse. Therefore, the potential for prosecution may be there.

Does anybody have any views?

[jokar]

I would have thought that unless that argument appears in the strategy document supporting the application then the failure to comply with B3 will make the BCO not accept it.  The Apeendices at A are quite specific about fire rating as you describe.

[CivvyFSO]

In my humble opinion they seem to be getting cavity barriers confused with compartment walls.

ADB 8.24 Compartment walls in a top storey beneath a roof should be continued through the roof space.
ADB 9.3 "....It is therefore not appropriate to complete a line of compartmentation by fitting cavity barriers above them"

>>but all they ask is does it comply with the RRO?<<

Article 8, duty to take general fire precautions.
Links back to Article 4, Meaning of "general fire precautions"
Measures to reduce the risk of fire on the premises and the risk of the spread of fire on the premises.

[CivvyFSO]

There is also mention in section 9 (cavity barriers) about the substances present on the unexposed side of the wall, which would back up my theory of them being confused between compartmentation and cavity barriers.

[Dinnertime Dave]

In my humble opinion they seem to be getting cavity barriers confused with compartment walls.

ADB 8.24 Compartment walls in a top storey beneath a roof should be continued through the roof space.
ADB 9.3 "....It is therefore not appropriate to complete a line of compartmentation by fitting cavity barriers above them"

>>but all they ask is does it comply with the RRO?<<

Article 8, duty to take general fire precautions.
Links back to Article 4, Meaning of "general fire precautions"
Measures to reduce the risk of fire on the premises and the risk of the spread of fire on the premises.

Here lays the problem, the protection that has been fitted is designed for the seperation within cavity barriers hence the 60mins integity and 15 mins insulation. The height between the false ceiling and the roof is approx 4 - 6 mtrs.

The problem occured because it is a set price build, the builder can then use anything that is suitable that gives the same solution (standard building practice on large projects I believe) questions have been raised by the BCO and ourselves, a fire engineer (paid for by the builder) has said that he does think its a great problem. We think differently.

Just looking for a few more bullets to fire back.

[kurnal]

Its the BCOs problem at the end of the day, but a compartment wall it certainly is not.

[Dinnertime Dave]

Its the BCOs problem at the end of the day, but a compartment wall it certainly is not.

It would be if they weren`t asking the fire authority`s consent to a variation under B3. Incidentally we have said that we feel it doesn`t meet the functional requirements. we have also indicated that it may not comply with the requirements of Article 8, roughly in line to CivvyFSO comments.

Thanks everyone for the comments.