Mezzanine Floors

[Keith1983]

We have what is essentially a large open warehouse which has had a mezz floor installed. It covers half the floor space. It has one starircase for access / egress. Our purchasing manager has been told that if we have a small office space up on the mezz floor that the floor should be 30 minute fire resistant. Is anyone aware of where I can find legislation specific to such a situation?

My thoughts are that seeing as the mezz floor isn't completely covering the ground floor of the building it wouldn't be forming part of a compartment and so 30 minute protection would be pointless?

If I had to advise on it without researching my gut feeling would be to have detection under the mezz floor to allow early warning to the office occupants.

I look forward to our fire bods take on this.

[Messy]

Hi.

Whilst obviously I cannot comment on your situation, you are right that fire detection is often required under a raised storage platform to give those above warning of fire.

However, the advice on providing passive fire protection to the structure may also be correct. However, cladding the structure in fire resisting materials is not to create a compartment, but is necessary to protect the structure and thereby fire crews who may be required to enter the premises. There is also limitations on travel distances for such floors, again to protect fire crews. Fire resistance standards can be reduced and travel distances lengthened if sprinklers are fitted.

IMO, there is a huge dichotomy here between ADB and the Fire Safety Order, as operational fire crews are not defined as 'relevant persons' in the RRO, so do not generally have to be considered (with 1 or 2 exceptions) during the RA process. However, ADB requires their safety to be considered!

I assume there is an architect or Approved Inspector involved in designing the floor. IMHO, it is for him/her to advise on the fire protection, so this may be your first port of call. However, for background look here:

http://www.planningportal.gov.uk/upload ... c_B_v2.pdf" onclick="window.open(this.href);return false;

Section 7 on page 69 and tables A1 and A2 from page 122 refer. But dont get bogged down, let the architect earn their (ridiculous) fees! !!

[bernicarey]

Very good points Messy.

One thing though, perhaps I'm just being a bit blank this morning, but can you confirm what ADB stands for...

I'm assuming you mean Building Regs, Approved Document B, which would only apply to new works. Of course, Keith's 'Office' would be new, but I'm not sure how far and wide the Regs would apply in terms of the Mezza Platform
I guess like you, I'd say get the architect to tell you.
But then I'm not sure anyone is likely to employ an architect just to have an office put up; I'd assume any local builder would do that without formal drawings.

[Keith1983]

Thanks for that Messy, I need to find out exactly where this requirement has come from and speak to whoever has communicated it to our man who is looking after the installation of the mezzanine floor. I do wonder if there is a case of miscommunication so I will get it form the horses mouth so to speak.

I must admit I had not considered fire crews when considering the requirement. I have just had a look at the ADB and it does look as if 60 minutes resistance is required for our application, or 30 minutes if the area is covered by sprinklers. It isn't covered by sprinklers and neither will it be. 60 minutes it is then!

Thanks for your help Messy! I was looking at this from an occupant safety perspective and not a Building Regs or fire crew safety perspective. As you say it is a shame the ADB and RRFSO can't be a little more coordinated.

Berni: The building that the mezz floor is going in is indeed new, it is primarily for storage but it is a seperate building to anything existing and we are looking at stationing a couple of people in there.

[Keith1983]

Just one more quick query. I have referred to the ADB for the standards for certain types of buildings, facilities and installations. This is great information and completely relevant to my issue. What I'd like to know though is that can these regulations be open to interpretation. Not because I'm trying to take shortcuts, but completely the opposite. Our local buildings inspector has said that we can relax the 60 minute fire protection under certain circumstances. Can they actually do that, and if they do will they provide us with evidence that they have authorised this? For my purposes it would actually suit me if there cannot be any interpretation and that they must be adhered to strictly. I ask this as I know some information in the RRFSO such as travel distances etc can be "guidance" and can be considered and wavered from dependant on circumstances.

[bernicarey]

Hi Keith


I took your OP ...

We have what is essentially a large open warehouse which has had a mezz floor installed.

To indicate that this was a significantly older installation that you were now adding an 'office' to. Thanks for clarifying.

As to your Building Inspector and any relaxation, check out the reference Messy gave of Doc B page 69, para 7.8 I think that gives you what you're looking for.

[Keith1983]

It isn't an older installation Berni, the building is new as is the mezz floor.

The "Variations and Special Provisions" section is about as clear as mud isn't it! But I guess that does answer the question that variations can be considered.

[Keith1983]

Right then, our Buildings Inspector has come back and told me that if the mezzanine floor is used solely for storage then it will not require any form of fire resistance. This goes against my interpretation of the regulation, but as a building inspector surely he knows better than me?

[Messy]

Just to clarify, at start of each section there is a section known as 'the requirement'. This is the legal bit.

page 15 shows the requirement for B1 that says (in summary) "the building will be safe and have enough exits blah blah"

That's the statutory bit which everyone must comply to -

The rest of B1 gives guidance on how you can achieve the requirement in a range of different circumstances. Building inspectors can allow requests from architects, approved inspectors or even Joe Blogs to meet the requirement in another way as long as its at least as effective

My local building control team are robotic idiots (no offence!!) and stick to the guidance as if its a requirement. So if you have a team who offer flexibility, take full advantage of it!

[Keith1983]

Thanks Messy. I really appreciate the assistance form this thread. Just as a heads up the latest version of the ADB is here: http://www.planningportal.gov.uk/buildi ... ocumentsb/" onclick="window.open(this.href);return false;

You can choose between residential and non residential.

[Keith1983]

I've spoken to our local council building control and they tell me that the mezzanine floor does require 60 minute fire resistance regardless of if it is being used for storage. I'm going to check our planning permission documents and see what they say. My limited knowledge with such things tells me that we have planning permission and as long as we build it in line with that permission then all is rosy!

[Keith1983]

Right then here is the conclusion. I apologise for going on a bit on this one but I had to let it all out somewhere. I now have absolutely no faith in the planning system and the regulations that go with it. As Messy and Berni mentioned previously the inspector is choosing to enact, or in my opinion abuse his position to be able to "interpret" the regs and relax certain parts of them. I consider this to be a sham. The dimensions he is allowing are a million miles from the guidance. When he comes to sign this off I will be asking him exactly what considerations he made when he decided this. One thing that makes this sit even more uneasy than it already does, is that this Building Inspector has been brought in by the mezz floor suppliers from some distance away? I don't know why you'd do this when there are 101 local people with the same qualifications and authorisations to inspect this building. I believe the mezz floor installers were a good bit cheaper than the others who quoted and I would be willing to hazard a guess as to why. I'm not a happy bunny but I'm going to have to chalk this one down to experience and take the positive that I am now much more familiar with the "Building (complete waste of time, money and paper!) Regs. I was not with the business during the procurement stage but I do feel that I am well equipped to help out and prevent making the same error in future. So not a complete waste of time but very time consuming and frustrating none the less.

Thanks to those that have posted on here and helped me find my way with this one.