AnthonyB

If you mean battery only (Grade F1) no. Grade F alarms are not acceptable as they only have one source of power. If you are a 4 storey s257 HMO (which isn't actually a HMO but flats not converted to Building Regs such as from a house) then guidance requires the common system to be Grade A (commercial type fire alarm) with the individual flat systems Grade D1 https://www.rla.org.uk/docs/LACORSFSguideApril62009.PDF

It would be normal practice to protect the stair by underdrawing it to 30 minutes fire resistance using plasterboard or glass reinforced plasterboard of the required thickness (usually 12.5mm, the British Gypsum White Book gives suitable detail).

How many floors? The full specifications can be found here: https://www.rla.org.uk/docs/LACORSFSguideApril62009.PDF

The legislation didn't cover social housing landlords as it wasn't considered necessary as they were deemed to be responsible and unlike the 'rogue' private sector not needing extra legislation. The Housing Act still applies and is enforced by the council via the housing health and safety rating system (HHSRS) - lack of suitable provision of smoke alarms would be a hazard enforceable under this system.

The default approach in an FRA would be to ensure the cupboard had an FD30S door kept locked shut or be taken from use - but the legislation & guidance is risk based and in theory in a managed use communal area use as it is for non combustible items could be tolerable. I have risk assessed a set of flat blocks with a very active and involved tenants/owners management committee and tenants/owners that are similarly cooperative and was able to allow managed communal area use and some non fire resisting cupboard doors in the FRA with the support of local enforcement officers. Having said that such a situation is sadly an exception and in many blocks zero tolerance and 'belt & braces' precautions are the only realistic approach. So flexibility is possible, but it requires buy in from all residents to ensure it's workable.

Even a new fire door does not have to have third party certification, so as long as they are inspected and maintained by a competent person and replaced if genuinely beyond repair then that should suffice.

There's nothing stopping a fire exit being in normal access route from a fire safety point of view, usually it's a security issue where access is limited to just one normal door.

p97-100 https://www.local.gov.uk/sites/default/files/documents/fire-safety-purpose-built-04b.pdf

Exactly my point. Technically very little is actually required in law, the FSO just sets broad functional requirements giving flexibility in how you comply and it's possible to safely and legitimately depart from the benchmarks such as those in British Standards, but it has to be justified and provide an adequate level of safety, so the default is to follow them - and I've seen to much wrong with uncommissioned equipment (and also those where they haven't been commissioned properly by a supposed competent firm) to justify not doing it. With no commissioning you can't tell if the unit is below weight on first service so will never be 100% sure of functionality (especially with CO2 where weight is the main way of telling if it's OK)

Whilst the shutter is the more modern approach, there are plenty of existing premises where FD30 hatch doors are fitted, the 'keep fastened shut when not in use' approach is used.

Is your flat door not a fire door at all or just an older one? In smaller blocks a risk appropriate tiered approach to the minimum standard door is advised in government guidance - although a current standard FD30s doorset is of course the best protection.

But uncommissioned extinguishers are often incorrectly assembled, damaged and not serviced for over a year (no installation date) so it would be prudent to have them commissioned. The client is taking the full liability for failure to perform and having an adequate system of maintenance by not doing so.

Powder still has it's place, some examples: - Spill & running fuel fires, where foam can struggle - Large fires requiring rapid knockdown - Low temperature areas - Class C fires where there are specialist staff to safely extinguish the flame and manage the resulting explosion risk - Multi risk areas where the secondary damage & personnel risks have been assessed as tolerable. Due to low cost it's still the most common multipurpose extinguisher for the home, although ABF Foam & Water Mist would also suit. Quantities of foam & CO2 extinguishers are based on risk, fire rating & travel distances - in some cases you might have a fire point of 2 x foam and 1 x CO2 Extinguishers that have passed the 35kV test are suitable for direct use on electrical fires up to 1000V - it's a peculiarly British thing that they avoid pointing this out and prefer to sell a CO2 as well. AFFF is an Irritant in concentrate (certain special blends are corrosive), but not a toxin or carcongenic. It's harmful to the aquatic environment and older blends were worse for the environment generally. Water (or water and wetting agent) is the best Class A medium as it cools and soaks, however powder can be effective if the right type: - BC Powder, usually an alkaline bicarbonate based medium is very limited on Class A as there is no cooling or smothering effect, just chemical inhibition, making it ineffective on anything but the smallest surface fire - ABC Powder, usually an acidic ammonium based medium has a greater effectiveness on Class A fires as it fluxes when heated and sticks to burning embers having a smothering effect as well as inhibition. There is still a risk of re-ignition in deep seated fires

It's far more than you need, but if you want the extra protection then why not!

Looking at all the various questions on here for different premises it looks like you need to employ the services of an external competent person. Call centres usually have a higher density than offices and in older buildings, constructed based on office use and before call centres were a thing, will usually only have means of escape based on the lower office density and so a change of use results in overloading the capacity of the escape routes, both vertical & horizontal. I would first calculate the maximum capacity of your existing escape routes as this often is where the limiting factor comes in.

Foam extinguishers are suitable for Class A fires as predominantly water based and in the UK all carry a Class A rating (in some cases a very impressive one allowing an extinguisher to cover twice the floor area of a plain water jet extinguisher). Whilst the use of plain water spray is preferred for environmental reasons where there is no Class B risk a large number of extinguisher companies still install foam spray

You will also find most of those special user exemptions are now expired and the only remaining use of any note is on board aircraft and that expires soon so that no one will be allowed to use it. I suggest you also actually read the Equality Act.....😁

Is the main hall provided with smoke ventilation?

The common areas should have emergency lighting, although if not fitted retrofitting would be considered a lesser priority in risk assessment guidance than matters related to fire doors and compartmentation.

The Housing Department are usually the lead enforcer in HMO's although both the Housing Act, HMO Regs & Fire Safety Order apply. Existing doors upgraded using third party accredited products in accordance with manufacturers instructions should give adequate performance such that you could provide a suitable case not to replace them. Enforcers can only suggest one solution and if you have a different one that achieves a similar level of safety they are meant to accept this (& appeals and determination processes exist to support this)

Ideally - too many internet bought extinguishers are damaged in transit, lost pressure or incorrectly assembled by the user. Some construction companies use the P50 range in cabinets and reuse them from site to site as they can complete the maintenance themselves.

If those are compartment walls (as they could be) you would expect a self closer.

Without seeing the layout of the building I can't be certain

Building Control will often insist on the cut off, if the exposed surface area of the frying risk exceeds 0.4sq.m. there should be fixed suppression. You don't need the AFFF, over complicates things - the Wet Chemical will cover Class A & F (and increasingly often B as well) and the CO2 the electrical

No