Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 11 replies
  • Subscribers 32 subscribers
  • Views 1589 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Fire alarms, detectors and so on, a query

mapj1
I am appealing to those who do fire alarms, and have some knowledge of proper flat building technique, for a bit of insider knowledge before I may or may not decide to take issue with thre freeholders agents .

We have recently purchased a flat, and to be fair, as we dig deeper into renovation, there are a number of things about it that concern me. One relates to the fire alarm system which is the kind with a simple panel in the hallway, and sensors and sounders in each of the 20 or so flats in the building and the common area.

To set the scene the building is brick built, solid walls converted Victorian school type of thing, and it looks rather as if at no time in the last 20 years has any person working on it in any way missed any opportunity to cut corners, use the wrong coloured bricks, confuse mortar with cement, put woodscrews instead of bolts in the switch pattresses etc. so the warning signs are there.

Our flat is ground floor, and our ceiling is uneven, now very obvious after the  removal  of partition walls due to a damp problem that required removal of the floor and filling with cement. but that is not this question. In any case the ceiling is made of a frame of 2*4 timbers clad in  double plasterboard. In some cases this is below the floorboards of the flat above by about 3 feet, in other places more like a foot (the word 'uneven' does not really accurately capture the full condition, every cupboard and room seems to have been done by different teams who never met or looked in the other rooms, nor indeed possessed a working spirit level). This means there is a large irregular height void that as far as I can tell peering through some holes in  ceiling where we have removed the previous owners light fittings , has no lagging or fire detection in the void, just a clear view up to the remains of a victorian lath and plaster ceiling where most of it is missing, though the few remaining laths support T and E wiring to the flat above, whose floor boards are mostly visible.

Am I right in assuming this is not really to current fire standards ?

How should the ceiling have been constructed, I presume  fire integrity, sound proofing and thermal isolation should all come into it, and what arrangements should prevent or warn about a fire in the space between us and and the dancing elephants tenants in the flat above.

Should there be detection in the void ?

The free holders are a company that work through an agent, and the whole thing is quite tedious as they are very good at claiming that anyone else is responsible but them so I'd like my ducks in a row before going all para legal.


  • 0
    An old discussion here about fire detection voids. It may be an introduction to the matter. I hope that it is still current.

    http://firealarmengineers.com/forum/showthread.php?tid=4821&page=2



    Z.
  • 0
    Double boarded plasterboard (usually with joints staggered) sounds to me like it was intended to be the fire barrier betwen flats - so I'd guess the void above would 'belong' to the fire compartment containing the flat above.


    I might not have expected much thermal insulation between two internal areas as if both are occupied there wouldn't be much of a thermal difference between them so not much energy saving to be had. I would likely expect acoustic insulation in a modern conversion (which of course is usually mineral fibre not much different to some common thermal insulation) but I think that's a relatively recent requirement so wouldn't be surprised if it (legitimately) wasn't present in work done some decades ago.


    Then there's the issue that buildings don't necessarily have to be up to current standards - barely meeting the standards when the work was originally done and subsequently not making it any worse is usually sufficient to meet legal requirements unless there's any contractual basis for anything more.


       - Andy.
  • 0
    Hmm. that fire alarm thread is interesting, thank you

     

    The need for void detection is nothing to do with category. If a room has detection and a void greater than 800 mm then the void needs detection. this is for L1, L2, L3, L4, L5, P1 & P2 categories If the void is deemed a low fire risk or unlikely to cause a fire to spread beyond the room then you can omit the void detection and note it as a variation on the certification.

    So in your case if the void has good fire stopping and a low fire risk then no need for void detection




    Now I suspect that  the open  backs of our flats down lights or the random wires through the cobwebs and lath and plaster do not really count as "good fire stopping and a low fire risk"  but I think of one organisation that will argue tooth and nail that it does if it saves them some money.


    I realise that repairs generally do not need to be to current standards but the ceiling will have to be be redone anyway. I'll measure and see what side of 80cm it is. If it is that easy, we may just put  try to get it put back a bit back higher so the void is smaller. I can see myself paying privately to upgrade the acoustic aspects.

     


  • 0
    If you did have some kind of detector in the void - would it then have to be accessible (for inspection, servicing, repair etc)? If so would you then need a hatch in your ceiling - and would that be a good idea in a fire barrier? Or should the detector 'belong' to the flat above (and be accessible from there)?


      - Andy.
  • 0
    Mike,


    Part B of the building regs gives all the details you need about the fire resistance of the structure (and a whole lot more). I am not including a link to the gov.uk website but it's easy enough to find


    I would agree with Andy that the double skin plasterboard is intended as the fire compartmentation and therefore would strongly recommend you repair/seal it. if the building is less than 5m overall height the requirement is for 30minutes resistance and if it is 5 - 18m overall height then 60 minutes is required.


    Logically it follows that the void is part of the flat above as far as fire compartmentation is concerned and if you put a hatch in it to access smoke detectors it would have to have a seal to the correct fire rating.


    I hope this helps and you find a reasonable solution. It sounds a far nicer place than the modern "Institutional" style flats we build these days.


    regards
  • 0
    As others have identified, the line of fire protection is indeed your ceiling, the void then falling in to the compartment above thus any penetrations should meet requirements for the stipulated fire resistance of the compartmentation, which is, as burn has noted, generally height dependent. 

    It would appear that the fire strategy is simultaneous evacuation on the triggering of the common fire alarm system. You are fortunate to be on the ground floor as there is bound to be issues with false alarms, especially with what is likely to be a L2 system serving 20 flats. The system may have been stipulated to mitigate the difficulties in providing concrete assurance that in a Victorian building, the individual flats could survive burn out. 

    With respect to sound attenuation, BC focus on that is only relatively recent so you might have to try your best to mitigate the effects. Certainly if your flat has solid walls which rise through the building then both air borne and solid flanking transmission will be inevitable.

    if you are removing your ceilings then a BC application is required (and advised).
  • 0
    Thanks for that additional info and thoughts.  Actually I had not considered the BCO, and no one else has mentioned them, so that is a good point, and may be a potential ally for improvement. I guess anything more than just patching up counts as significant new work. Certainly there are a number of aspects in the rest of the building that look like they ought to have been inspected and probably were not. (foul drains being another one)
  • 0


    is the condition of what is left of the old lathe and plaster ceiling so poor it is likely to fall down?


    might be worth putting new sound-insulated ceilings in at (or just below) the level of your lowest ceiling, they don't necessarily need to be double pboard as the compartment containment would be above it, 


    lastly don't leave inspection holes to voids open for too long and check your insurance covers you and the rest of the building if there was a fire while any ceiling is down.

  • 0

    OlympusMons:

    lastly don't leave inspection holes to voids open for too long and check your insurance covers you and the rest of the building if there was a fire while any ceiling is down.




    Madam's rewire is progressing reasonably well and the new Pookey wall lights are ready to be installed. Incidentally, they seem to be well made. The fixing screws are well positioned and there is a good enclosure for a choc block, which does not have to sit in a recess in the plaster.


    Next step is to remove the unsightly 1970s (?) downlighters. Madam has been told, no, I am not going to make good her lath and plaster ceiling, but I have donated some spare laths.


    I'd be interested to hear (read) any views on responsibility for ceiling integrity. (Property is detached 2-storey dwelling.)

  • 0
    Hi Chris. By "ceiling integrity", I assume you mean "will it all fall down", quite possibly. I wouldn't fit downlighters in a lathe and plaster ceiling, nasty job. Replacing them might be tricky too.

    I was once on a job where we were replacing a bressummer beam over a bay window and the ceiling below was ornate and needed saving. We poured a slurry of something like plaster of paris onto the top of the (hoovered) ceiling and embedded mesh which was hooked over the joists and new steel. Think it worked.


    Mike, is there a recent fire risk assessment which covers the voids?





Community Rules & Guidelines