The new approved documents B major changes and bloopers

[kurnal]

I thought it may be helpful to start a thread discussing some of the very significant changes in the new ADB.
Have spent all day reading the new document  (well I suppose it beats watching the Rams- it gets a little tedious when they keep winning every week....).

New bits that caught my eye:
Regulation 16B that is intended to ensure that sufficient information is recorded to assist the responsible person to meet their statutory duties

Changes to the smoke control arrangements in flats, surely some bloopers in diagram 7 and 8 page 28 concerning ventilation and a very confusing paragraph 2.26.b.iii stating a smoke shaft should have the same fire and smoke resistance performance as a E30s fire door??

The loss of references to angle of divergence RIP

New confusing formula for calculation of merging flows at fire exits that turns a simple mental arithmetic job into a calculator job

Some new rules on progressive horizontal evacuation  with rules that dont fit any building design for care homes that I have ever seen

para 16.1 in B5 refers to tabe 18- it should be table 19

and finally for now

Where fire mains are required,  if no hydrants are in the vicinity there is a new requirement for the developer to install a private hydrant within 90m of the inlet, or provide a static tank. That could be really sticky- can anybody get new hydrants these days? And who will maintain and test it? And will it mean digging up somebody elses property? Cant see how that can work.

[wee brian]

I guess the rules for care homes will be for new ones, so they won't be like the ones you have seen before.

[kurnal]

Yes so long as someone doesnt use it as an excuse to argue against PHE in an existing building that is altered but where the layout doesnt conform to the new ADB. Its a solution that supports PHE very well but suitable evacuation procedures should be the sole remit of the responsible person and the risk assessment.

I still think the racecourse layout is the ultimate for care home design from all points of view.

[kurnal]

The new ADB sets out recommendations for fire detection in flats - every flat should have a system to  BS5839 pt 6 LD3 , and the paragraphs that follow go on to say that at least one detector should be provided in a flat, in the circulation area of a conventional flat with an entrance lobby.

There is also no requirement for doors within the flat  to be self closing.

Now I am having  an exchange of views with a local authority BCO. His view is that I can only omit the self closers if I install detection in all habitable rooms. If I just install a single detector in the entrance lobby I must fit fire rated self closers to all doors. Either one or the other.
My view is that a single detector and no self closers is fine according to the ADB.

I do recognise the benefit of further detection but I want to achieve a baseline spec to meet the benchmark and then give the client best advice so he can make choices on a cost/benefit basis.

Have I read the document correctly or do you think the BCO  is right

[wee brian]

You are right the BCO is wrong

[jokar]

What about Diagram 17, on page 40 in Volume 2, surely the "T" Junction corridor should have the FR carried across the partition in the room, otherwise a fire starting in one room could go through the partition and block both escape routes.

[AM]

What about Diagram 17, on page 40 in Volume 2, surely the "T" Junction corridor should have the FR carried across the partition in the room, otherwise a fire starting in one room could go through the partition and block both escape routes.

It's different from the general guidance, but the diagram is the same as in the 2000 edition ADB.

Also, have a look at section 4.34a. It says that lobbies are required for single staircase conditions except for premises covered in paragraph 4.6. It would appear that an 'a' is missing, which would refer you 'small premises' described in 3.33. Without the 'a', it allows staircases without lobbies to five-storey office blocks.

[Martin Burford]

Thought everyone may like to know the Guide for Transport premises asnd facilities is out.
Conqueror

[kurnal]

Came across a new care home yesterday with fire doors to all rooms where they would be expected but no smoke seals to kitchen, laundry and plant room. The builder was on site for snagging and we had a forthright discussion- he pointed out table B1 in the new approved document B which specifies FD30 not FD30S.

He was right in so far as the the table appears to recommend this but I persuaded them through risk assessment that smoke seals were  definitely required on these high risk rooms. Any comments welcome

[wee brian]

Wow a builder wh has heard of ADB!!

"Persuaded them through risk assessment" it used to be called something else!

[jokar]

Is he putting in new doors or routing in the strips and seals?

[AFD]

Only had a quick look at new ADB, but is 'progressive horizontal evacuation' a form of 'phased evacuation' ? I think it is, therefore stairs should have 2 door protection ?

[kurnal]

Jokar
he is putting in a mix of new door sets in some places but often just a fire door blank with a routed groove round the perimeter and sticking in an intumescent seal. He has put combined seals on the staircase doors and bedrooms but the high risk rooms just fire seals. Ho Hum.

AFD
I dont think so- I think the context of phased evacuation with the lobby protection is intended to apply to high buildings rather than PHE but I can see where you are coming from. For phased evacuation we are usuially focussing on vertical escape and PHE is what it says- looking at the initial horizontal phases- and always in a building with choices of vertical escape routes should that prove necessary. So the compartmentation we rely on to make it work is in between staircases rather than adjacent to them. Hope this makes some sense.

[wee brian]

Dear all - check out the DCLG planning portal. They have issued an amendment doc for Vol 2.

www.planningportal.gov.uk

[AFD]

Kurnal,
surely two door protection also protects people staying on upper floors and being moved horizontally from a fire on a floor below, as well as reducing smoke ingress into shafts, as able bodied ( visitors etc.) escape vertically and staff proceed to assist in PHE.  HTMs have all stairs lobbied ?