Hello Lyledunn. Regarding the accountability for the missing fire barrier penetration, in my opinion it is imperative to identify the responsible party. In case of a renovation with a principal building contractor, I personally would have expected that they would have employed a team of experts to ensure that all penetrations through fire barriers are sealed. However, if the hole was made after the renovation, it becomes the installer’s responsibility to seal it to the best of their ability and then seek professional assistance in sealing it completely.

depends which side you think the fire is coming from there are some good demos here.

https://www.youtube.com/watch?v=t-fdlWOoP2o

 actual demo, rather than Advert waffle starts about 1 minute  in.

If the fire is in the room, and coming out via the socket and it's back box into a wall partition, then it may be very worthwhile.

you may of course want the metal versions of the dry lining box.

example to be used in case of doubt about which way the fire is coming from ...

M.

I have a question that deviates slightly from the original post if you don’t mind helping with. The fire strategy document for a new refurbished building specifies that the walls have a fire resistance rating of 30 and 60 minutes, but there is no mention of the ceilings. The ceiling are constructed using standard gypsum board with a thickness of 12.5 mm. Recessed emergency lights and circular dry lining boxes are installed through the ceilings and fire detectors  with the latter being fire-rated dry lining versions. Given this information, is it reasonable to assume that the ceiling should be constructed using fire-rated boards to ensure adequate fire protection ?

Are the two sides of that ceiling part of the same zone for the purposes of fire spread and evacuation ?

For a comparative example in a domestic house with an open  stairway linking upstairs and down, the downstairs ceiling and upstairs floor are not two separated fire zones. However, if the stairway has a fire door at one end or the other, or is in its own stair well separated from both floors by fire doors - as you would in a block of flats perhaps, then it is the designer's intention that the two floors are not to be considered one fire zone. In the latter case cut holes in the ceiling at your peril, as you are under obligation not to make the fire safety worse than it was originally. Might be worth downloading and reading part B of the building regs, or at least the bits that pertain to the building type.

Some refurbishments are allowed a relaxed standard if the building predates the current rules and is not practical to change, but that exception should be recorded, and still needs to be as good as can reasonably be done in the circumstances.

(sometimes 30mins is permitted instead of 60 - but normally only for things like house to flat conversions in Victorian properties of 2 story or less.)

Mike

Hello Mike. Thank you for your response. The building will be a public facility and each room can be booked separately. There is a fire door at the lower end of the stairs. The walls that border the neighbouring property have a 60-minute fire resistance rating, and the walls that partition the rooms have a 30-minute rating. The rooms also have fire-resistant doors. The fire strategy only required that the ceilings be fitted with 12.5mm British Gypsum Gyproc boards. 

Sounds like 30 mins might be the intention, do you know the ratings of the doors ?  but without seeing it however it is hard to know. Seems a bit weak, for example our 2 story scout HQ is based on 60min doors and partitions, but then folk do occasionally sleep there and there  is an inner room kitchen. Also depends on how fast you can get out, distance from furthest points to exits etc. - As I said, part B is worth reading, there are a lot of cases to consider.

If it is 30 min partitions, then so long as it is the right sort of 12mm board, and I appreciate now it has been plastered you probably cannot easily tell, it would also be half hour rated. Then whatever it fitted to this must preserve the rating, i.e. boxes for lights etc to the same or longer fire rating - and they all need to be properly fitted as per maker's instructions etc.

Mike

I appreciate your prompt reply. Regarding the installation of the switch and socket dry lining boxes in the walls. After inspecting the installation, I noticed that none of the boxes have intumescent pads. Upon reviewing the fire strategy as discussed, I found that the walls have specific fire resistance ratings of 30 and 60 minutes, while the ceilings do not have any specified rating. Therefore, I wonder if all the boxes throughout the building should replaced or have fire-rated pads to ensure compliance with the fire strategy. I will have to check the doors tomorrow.

AMK said:

The walls that border the neighbouring property have a 60-minute fire resistance rating

A typical requirement for compartment walls between buildings.

AMK said:

and the walls that partition the rooms have a 30-minute rating.

A typical requirement for walls that form protected stairs, lobbies and corridors in the same compartment.

AMK said:

the walls have a fire resistance rating of 30 and 60 minutes, but there is no mention of the ceilings.

It is the floor that is required to meet the required fire resistance and this will vary depending on the height of the building, its purpose group and whether it has a sprinkler system. If you look at British Gypsums White Book, for example, you will see some very fastidious detailing for protecting floors with the ceiling and the floor being treated as a composite in terms of overall fire resistance. 

So sticking downlights and other apertures in these ceilings, even with fire hoods, can compromise the fire rating detailed in the White Book. 

Clearly, in all cases, it would be prudent to minimise openings in any element, that has a fire resistance. It is particularly important that electricians carefully consider how they propose to install their wiring systems to avoid compromising the fire resistance integrity of the building. 

My photo above indicates a total lack of care in that regard! 

With respect to fire doors, they are normally required to be half the rating of the wall into which they are set with certain minimum values. If the wall is required to be 60min, the door is usually 30min on the basis that combustible material is usually set well clear of doors to allow passage through. 

The use of stud partitions, either wood or metal offers a chance to avoid chasing masonry walls to install sockets and switches but one needs to exercise care when the walls are required to be fire resistant and particularly where they form protected corridors and the like. 

On the last large job I was on, this problem came up. One of the Contractors had fitted plastic plasterboard boxes on an 'external' wall [1]. When inspected, this non-compliance was brought up, and all of the plastic boxes had to be changed to the metal plasterboard boxes with intumescent pads in them.

They were also very keen on intumescent sealing on any hole, however small between fire compartments.Which was quite surprising, as their design was truly bad, with safety services being powered by the same supply as for general use, and a 200 amp fuse being used for 75 flats with electric heating. Of course, during functional testing, the incoming fuses blew numerous times until the incoming supply was upgraded. They never did fix the safety services supply.

[1]'External' being a wall that adjoins another flat or communal area, internal walls could have plastic fitted, as the flat was considered as one fire compartment.

Hi Alan, if the sockets on the external wall were standard plastic dry lining boxes but the intumescent pad manufactures/ fire stopping specialist confirmed that the required fire resistant time had been tested in accordance with the relevant standard, is this really a non-compliance? From what I’ve seen fire stopping is all about following the tested detail

No idea, I was only working there when the Inspector came round. He wanted metal in any backbox that adjoined another flat, pads were in the plastic boxes, but it wasnt enough for him.

No idea, I was only working there when the Inspector came round. He wanted metal in any backbox that adjoined another flat, pads were in the plastic boxes, but it wasnt enough for him.