Leasehold shared loft

[Fraudley]

hello ladies n gentlemen,

May i ask for your opinion regarding a situation i was made aware of today please?
It concerns the loft of a leasehold property. The loft is above 2 separate flats. Whilst both flats have loft hatches they are not permitted to access the loft for any reason or use it for storage. The separation between the flats and the loft is not something I have seen in housing as it comprises of boarding and 2 inches of silver sand. The Warden call system was installed in the loft. A risk assessor has asked for the loft to be properly divided above the flats partition. I understand he is thinking about fire spread but I cannot see why the RP would go along with this suggestion. I would have thought once it's confirmed the separation is in no way compromised, possibly installing additional detection or relocate the warden call system, there's no rational need to even consider the RA's suggested action. I'm still waiting for the assessor to explain their reasoning behind their request. Am i missing something glaringly obvious here?

Thanks in advance.

[William 29]

You maybe missing something if the walls to the flats do not extend to the underside of the roof (I assume you are on the top floor). Do you know the fire resistance level of the flat ceilings and does the loft void extend over both flats and/or the access corridor?

[kurnal]

Benchmark standards would provide for full compartmentation to the roof. However many buildings converted to flats fall short in this regard. It might have been that the silver sand and boarding were accepted as an alternate, horizontal form of compartmentation between flats but you are unlikely to find any evidence of approval. During the housing boom of the early 80s foamed perlite cement was widely used in this way but personally I have never encountered solutions involving sand.

The assessor is pointing out the shortcoming, the solution may not be straightforward. Compromise may have to be made, for example providing a barrier with less than the requisite fire resistance. I would base my recommendation on the risk assessment taking into account : how high; how many flats; other variations from best practice ; building construction, protection to MOE etc.

[wee brian]

The sand might be there for sound insulation (its called pugging , I think).

There was a fatal fire in a sheltered block where the lofts were undivided (in the last couple of years). I understand the arguments against separating the lofts, but I would do it.

[David Rooney]

Are you sure the sand isn't vermiculite for heat insulation ??

Sand would be very heavy to support on a layer of plasterboard .........

[Fraudley]

Thanks all,

William as far as I know the whole loft is open, so above the flats and the landing between them.
Brian, was that related to the poor compartmentation?
David/Brian No idea about the actual sand. I've only know what I've been told. I agree I'm not comfortable with the concept and I'm surprised it is there to act as a fire barrier.

My initial thoughts were to ensure the integrity of the ceiling which will probably mean removing the current barrier and replacing it. Whatever it takes to ensure there is 60min protection. Other thoughts are to ensure that there is a full evac policy in place. AFD in loft linked to escape route. Investigate if an AOV is feasible.

The cost of the proposed sub division is going to run close to 8k. I suppose I'm trying to see if it can be sensibly risk assessed/managed out without compromising safety.

[wee brian]

yes the death was linked to fire spread through a loft.

Google "sand pugging" listen to uncle Brian - he's a reformed builder.

[kurnal]

Before spending too much in the loft it would be wise to check the construction of the walls below,  I have come across many a conversion with lath and plaster walls where you would expect masonry. There are also fire curtains available with full integrity and insulation, these can be much cheaper / easier to install than a stud wall.
There are so many substandard buildings and it is often not practicable to bring them up to current standards, if you want your hair to stand on end go and have a look at some of the tenement blocks in Scotland where 6 storeys are commonplace and not a fire door in sight. Yes there's the occasional fire death but numbers are socially acceptable.

 Consider the level of risk, should we be spending a relative fortune on small premises when for example we have tower blocks in which the compartmentation has been ripped apart - remember the recent BBC coverage of a fire in a tumble drier in London that clearly spread vertically and horizontally and led to a full evacuation of the upper levels....but London fire brigade only commented on the risk caused by the tumble dryer.
The other alternative approach if nothing else will work may be full evacuation and alarm system. Don't just hug the code - risk assessment should be the order of the day. Does the housing officer have a view on this?

[William 29]

Thanks all,

William as far as I know the whole loft is open, so above the flats and the landing between them.
Brian, was that related to the poor compartmentation?
David/Brian No idea about the actual sand. I've only know what I've been told. I agree I'm not comfortable with the concept and I'm surprised it is there to act as a fire barrier.

My initial thoughts were to ensure the integrity of the ceiling which will probably mean removing the current barrier and replacing it. Whatever it takes to ensure there is 60min protection. Other thoughts are to ensure that there is a full evac policy in place. AFD in loft linked to escape route. Investigate if an AOV is feasible.

The cost of the proposed sub division is going to run close to 8k. I suppose I'm trying to see if it can be sensibly risk assessed/managed out without compromising safety.

I don't think what you are proposing would be adequate then in this case, if you see diagram 33 para 9.2 of ADB, the walls of the flats should extend to roof height, if so then the ceilings in the flats do not have to have any fire resistance, so your investigations into the FR level would not be required. By extending the flat walls to roof height you would prevent fire spreading from one flat to another within the void. This method also protects the roof space from a fire originating in the roof void or from a fire externally or from a flat window where a fire has vented and gone into the roof space.

So your suggestion to upgrade the flat ceilings to 60mins FR would not be enough and would not be the same standard as detailed in ADB, although building control and Approved Inspectors are passing the provision of cavity barriers and 60min ceilings as an equivalent standard and arguing would meet the functional requirements of ADB.

Also the DRAFT Speslized Housing Guide spesifically refers to this point, I stress this is a draft and it maybe removed from the final version but I doubt it will. See below.

76.4       The lines of compartmentation between flats located on the top floor of a building should, where there is a common roof void above, extend through the roof void in a continuous vertical plane to the underside of the roof.  This will ensure that the fire-resisting ?box? principle, extends into the common roof voids, to prevent fire spread between flats, and fire spread from a flat into other areas of the building, via the common roof void.  It is not appropriate to complete the line of compartmentation within roof voids by installing cavity barriers above the compartment walls that separate flats, nor to treat the roof void simply as a concealed space within which cavity barriers are installed at regular intervals.
 
76.5       The provision of fire-resisting ceilings within top floor flats would not normally provide an alternative means of achieving an equivalent standard of safety, as it would fail, for example, to address the possibility of a fire that starts within the roof void or that enters the roof void externally.

[kurnal]

William this is an existing building so why are we seeking to apply ADB? From the information given I believe this to be flats so the LGA flats guide would apply (not that it would make much difference to the guidance)


The OP has not given us enough information to argue this further in specific terms, we don't know the height, size, number of flats, age of the building, design standards used etc.

All I know is the UK economy could not stand the cost of bringing all buildings up to current standards, let alone trying to make existing buildings fit the current Building Regulations even though no material alterations are being carried out. Housing associations and landlords would be bankrupted. And how many lives would be saved each year? Maybe one or two?  That's why the legislation was based on risk assessment. it's a great tool, why are we afraid to use it?

[William 29]

William this is an existing building so why are we seeking to apply ADB? From the information given I believe this to be flats so the LGA flats guide would apply (not that it would make much difference to the guidance)


The OP has not given us enough information to argue this further in specific terms, we don't know the height, size, number of flats, age of the building, design standards used etc.

All I know is the UK economy could not stand the cost of bringing all buildings up to current standards, let alone trying to make existing buildings fit the current Building Regulations even though no material alterations are being carried out. Housing associations and landlords would be bankrupted.  That's why the legislation was based on risk assessment. it's a great tool, why are we afraid to use it?

It's about bench marking Kurnal not making it comply with ADB. I have seen buildings built only last year with the same "latent defect" as AI's and building control are passing them. I would argue that the current situation as detailed by the OP is so far removed from today's standards that action would be justified. (granted we don't know the full details)

[colin todd]

Big Al, the guy talks about warden call so it does not sound like general needs flats.  Wullie is right, as is Wee B. And on a point of accuracy few if any fire curtains have insulation to BS 476-22. ?8k is peanuts compared to the risk of unlimited fire spread over sheltered housing flats.

[kurnal]

Colin again we don't have enough information from the OP to know  the basic details of the building, the role of the warden call system or the fire strategy for the building.

Curtains are available with up to 2 hours insulation. I have commissioned their installation in the past.

My point is general, how far risk assessment has a role and how much prescription holds sway - prescription seems to be the dominant approach. I remain interested in the reason for this. I have a number of suggestions but am interested in the views of others.

William I agree we need benchmarks but IMO they should be taken into account in the risk assessment to arrive at a solution that is safe, practicable, reasonable and proportionate.

I used to work for housing associations and councils, we did hundreds of risk assessments and if I had gone in and applied ADB without risk assessment and proportionality we could have cost them more than their total budget several times over.

[Dinnertime Dave]

Big Al, the guy talks about warden call so it does not sound like general needs flats.  Wullie is right, as is Wee B. And on a point of accuracy few if any fire curtains have insulation to BS 476-22. ?8k is peanuts compared to the risk of unlimited fire spread over sheltered housing flats.

Claims to be certified to BS 476-22

http://static.rockwool.com/globalassets/rockwool-uk/downloads/datasheets/fire-protection/rockwool---fire-barrier-systems-ds-v2.pdf

[idlefire]

the guy talks about warden call so it does not sound like general needs flats.  

If only there was a some kind of recognised guidance document which explicitly covered specialized housing that could be used as a benchmark standard to answer this question.