Steel beam protection.

[Thomas Brookes]

Hello All,

I have got a Steel beam problem and would be grateful for any advice please.

The building is a 1920s building was a shop with a workshop at the rear. This has now been converted into a dance studio.

The part of the building in question is the rear areas, before the conversion (which was mainly cosmetic) apart from holding up the upper floor were three solid steel ornate supports (aprox 6inches diam, but solid steel, no hollow) on top of this was wooden beans across the building supporting the upper floor (aprox 12m x 12m).
The wooden beams have been replaced with steel girders, welded on top of the ornate supports making the upper floor far more supported than it was.
Also Building control have said they do not need any planning for what they have done at all, and have only said they want to see a fire risk assessment for the building.

Now some jobs worth architect (who has had his daughter at the dance school is saying that they have got to get the metal work protected.
I was asked to look to see if there is any other cost effective options as this is a non profit school for local kids and fairly much dont have massive funds, so I said I would ssee what can be done.

Normally I would tell companies that in control Doc B states metal supporting should have one hour protection, but with this being a charity case I thought I would ask you guys to see if there is any other options.
However and this is the help part please feel free to offer opinions etc.

Building control are not over bothered about the structural support of the building as this beam only supports what is a glorified mess floor and not any of the walls or roof.

Also most of the metal work is hidden behind a suspended ceiling. The fire exits are very good from all parts of the building including two seperate fire exits from the mess floor (one of which is a external metal staircase).

I am looking at a life protection point of veiw rather than a structual protection.
What I was looking at is possibly recomending a L1 fire alarm system for the building to give full automatic detection through out the whole building, this would give quick warning and evacuation from any part of the building within 1 to 2 mins max.
Also every door in the building is a fire door giving great seperation through out.
The local fire station (which is a main city station fully manned 24/7) is less than 1 mile away aprox 3 to 5 mins max.
Ensure all staff are fully trained in evacuation and what to do in the event of a fire.

What do you all think please.

Thanks

Tom

[Benzerari]

First of all, well come back again to the forum  Thomas

[AnthonyB]

If the structure is mostly unprotected original steel, what are the floors? Often you will find unprotected exposed wooden floors in this situation (often hidden by non FR false ceilings).

I've used L1 coupled with selected passive upgrading (escape routes and separation of high risk basement) in a building where there was a lot of exposed flooring etc but no budget to rebuild the interior (which is what in a perfect world would be done).

The nature & numbers of Relevant persons as well as the type of work processes affect what alternatives you can use.

[Thomas Brookes]

Its nice to be back, I felt lost in the wilderness.

AnthonyB, Ill to give you a little more info.

Max number upstairs would be 20 including the instructor(same down stairs) how ever this is the maximum not the normal. above the suspended ceiling is as you thought wood floor boards. The good news is that there is not a basement.
If you picture it would have been a two story house at the front with a brick built 12m square open area at the rear.Its this rear area thats the issue.
On both ground floor and upstairs have a fire exit door leading directly outside (no protection needed). Both up and downstairs have two seperate fire exit routes availible. The stair case from the downstairs to up are fully protected.

what do you think

[jokar]

I am at a loss to understand what fire loading would cause displacement of this beam in a dance studio.  Any fire would be noticed readily and people would evacuate long before a fire reached the stage of beam deflection, probably when the FRS arrive and put cold water on it.  An FRA would indicate little or no ignition sources and good control measures and if the BCO is happy a with a decent FRA then I would do no more.

[AnthonyB]

I'd be more worried about the wooden floors if unprotected 'gappy' planks, hence the need for AFD if there is a risk of a fire below whilst it is unoccupied and the floor above is.

Although for the cost of an L1 against an M or L5 (plus ongoing maintenance) it may well be cheaper in the long run to upgrade the floor with plasterboard, etc, etc as detailed in the DCLG guide

[Thomas Brookes]

thanks for that, you have fairly much, confirmed my thoughts.
It is a very easy upgrade on the fire alarm to L1 as all cabling is already in place.
Sorry Anthony forgot to say the floor boards have been plyboarded on top in two lyers and has had a special sound proofing between.