Steel Beams Fire Encasement

[Eviljames]

Hello folks, just wanted to check if steel beams that are fully enclosed within the void between a ceiling and the floor above need to be individually encased with fireboard within the void OR if providing a fully fire rated ceiling below will suffice.

 

Thanks in advance.

 

[nod]

The best and easiest way to do this is to use 50 mil MF studs Hung from the floor joists or the underside of the floor Then seal two layers of 15 mil FL to the underside of the floor and in and out of the joists 

It important that an air void is maintained between the steel and the PB 

Ill see if I can route any photos out from previous jobs 

[Mr Punter]

It is a good question and one where it is hard to find a definitive answer.  Promat state:

"Where beams are wholly within the cavity of a timber floor protected by a Promat SUPALUX®
ceiling then test evidence shows that the cavity air temperature of the floor is such that the
beam will be adequately protected to the same fire resistance by the ceiling that protects the
floor. Where the beam is wholly or partly below the line of the Promat SUPALUX® ceiling,
the A/V should be based upon the portion of the steel beam that is below ceiling level."

[Ian]

3 hours ago, Eviljames said:

Hello folks, just wanted to check if steel beams that are fully enclosed within the void between a ceiling and the floor above need to be individually encased with fireboard within the void OR if providing a fully fire rated ceiling below will suffice.

 

Thanks in advance.

 

Yes, that’s okay provided the ceiling, floor and perimeter walls are all fire rated however my preference on our commercial projects is for beams to have their own fire protection - the reason is that, over time when maintenance is needed to items that penetrate the ceiling such as lights, the maintenance staff rarely put things back the way they should in order to maintain the integrity of the fire rated ceiling eg when replacing lights with fire rated hoods.

Edited December 26, 2020 by Ian

[Mr Punter]

There seems to be a big emphasis on fire protection for steel.  I can understand it in multi storey, but for domestic I would think that once the floors reach >500C the place is finished anyway.

[nod]

35 minutes ago, Mr Punter said:

There seems to be a big emphasis on fire protection for steel.  I can understand it in multi storey, but for domestic I would think that once the floors reach >500C the place is finished anyway.

You only need to protect the steel on a domestic property if it is three story or more 

Same goes for fire doors 

 

I do a lot of fire protection as part of my business 99% commercial 

The idea is to create a fire compartment and isolate what ever you are protecting 

All fireproofing needs to be done before any services go in and the services just have to be worked around them 

If a duct or soil pipe has no way round the fire protected steel Then it must have its own fire protection 

 

On a three story house or a house with a basement BC will look for 1 hour plus protection 

Standard two story doesn’t need protection 

[juncopartner]

OP is this a domestic situation?  Please note you only need to achieve a specific standard of fire resistance,  fire boards are not required, all plasterboard has fire resistance but you would need thicker/more boards.

 

Fire resistance is required for a number of reasons, structural fire precautions, means of escape, fire spread between buildings, compartmentation etc.

OP please ignore Nod's comments, most of which is incorrect.

Edited December 26, 2020 by juncopartner

[nod]

1 hour ago, juncopartner said:

OP is this a domestic situation?  Please note you only need to achieve a specific standard of fire resistance,  fire boards are not required, all plasterboard has fire resistance but you would need thicker/more boards.

 

Fire resistance is required for a number of reasons, structural fire precautions, means of escape, fire spread between buildings, compartmentation etc.

OP please ignore Nod's comments, most of which is 

 

I think you need to read my advise more carefully 

and read what you have Googled again 

I’ve been designing and installing fire protection for over 30 years 

 

Just to recap on what I have already stated 

 

2 story domestic needs no fire protection 

3 story does 

I’m sure above will be googling away 

A little knowledge can be dangerous 

Check with BC 

 

 

[juncopartner]

2 minutes ago, nod said:

 

I think you need to read my advise more carefully 

and read what you have Googled again 

I’ve been designing and installing fire protection for over 30 years 

 

Just to recap on what I have already stated 

 

2 story domestic needs no fire protection 

3 story does 

I’m sure above will be googling away 

A little knowledge can be dangerous 

Check with BC 

 

 

A little knowledge is most certainly dangerous, care to explain why a 2 storey house does not require fire resistance?

[nod]

12 minutes ago, juncopartner said:

A little knowledge is most certainly dangerous, care to explain why a 2 storey house does not require fire resistance? ? 

[juncopartner]

"On a three story house or a house with a basement BC will look for 1 hour plus protection "
Does this apply to all 3 storey houses or just to ones with a floor level 5m above external ground levels
Perhaps you can quote me the reg that stipulates a fire resistance of more than one hour as well.
Would the basement also require 1 hour plus fire resistance.
If you don't know the regs, which you clearly don't, then I suggest you stop misleading people.

[PeterW]

3 minutes ago, juncopartner said:

"On a three story house or a house with a basement BC will look for 1 hour plus protection "
Does this apply to all 3 storey houses or just to ones with a floor level 5m above external ground levels
Perhaps you can quote me the reg that stipulates a fire resistance of more than one hour as well.
Would the basement also require 1 hour plus fire resistance.
If you don't know the regs, which you clearly don't, then I suggest you stop misleading people.

@juncopartner instead of playing the person - which you are - perhaps you could use your professional guidance and quote the correct regulations instead of telling everyone what the answer isn’t ..??

 

From ADB, 2020 amendments, a ceiling in a 2 storey residential class 1.(c) property doesn’t require anything more than 30 minutes fire resistance and this can be achieved with 12.5mm standard plasterboard. A steel enclosed in this floor space is therefore protects from the effect of fire and requires no further protection. 
 

Correct or incorrect ..? 

[juncopartner]

10 minutes ago, PeterW said:

Correct or incorrect ..? 

Correct
 

Just as a correction for Nod's reply.

Single storey buildings do not require fire resistance, when dealing with elements of structure.
Dealing with dwellings of more than one storey , any dwelling  (regardless of how many floor levels) with a floor level below 5m requires  30 minutes fire resistance, above 5m, 1 hour fire resistance is required.
There are no periods of more than 1 hour specified.
Basements require 30 minutes fire resistance regardless of the height of the building.
The above refers to elements of structure only however (and very briefly) there may be further requirements that may require fire resistance, ie separating walls, walls close to a boundary etc

In the case of a floor over 4.5m above ground level, a protected escape is required(fire doors etc to staircase), however this approach can also be used in lieu of escape windows at lower floor levels.

In reply to Nod, this was not googled, purely from memory, although I did have a quick look at my hard copy of the latest Approved Doc B just to make sure there's been no recentish changes I may not have been aware of.  
 

[Mr Punter]

So on the basis that the steel beam is structural, is it OK to just have have it in the floor zone with plasterboard on the underside to give the 30 mins or 60 mins protection required?  I sometimes get asked to spray with intumescent coating or encase the whole in plasterboard.  It is hard to find consistent advice.  The intumescent coating only works if you leave space around the beam, which in domestic floor zones can be impossible, but BC don't seem concerned with that aspect.

 

The product manufactures understandably tend to just promote and test systems that include lots of their product.

[Ian]

57 minutes ago, PeterW said:

@juncopartner instead of playing the person - which you are - perhaps you could use your professional guidance and quote the correct regulations instead of telling everyone what the answer isn’t ..??

 

From ADB, 2020 amendments, a ceiling in a 2 storey residential class 1.(c) property doesn’t require anything more than 30 minutes fire resistance and this can be achieved with 12.5mm standard plasterboard. A steel enclosed in this floor space is therefore protects from the effect of fire and requires no further protection. 
 

Correct or incorrect ..? 

The requirement for fire protection is based on height (for English regs) as this table in Appendix B4 of Part B 

 

[Ian]

2 minutes ago, Mr Punter said:

So on the basis that the steel beam is structural, is it OK to just have have it in the floor zone with plasterboard on the underside to give the 30 mins or 60 mins protection required?  

Yes, it’s okay just to have it in the floor zone but see my comments in the first post I made in this thread, and as with anything to do with Building Regs it depends on the opinion of the Building Inspector.

[juncopartner]

Just now, Ian said:

Yes, it’s okay just to have it in the floor zone but see my comments in the first post I made in this thread, and as with anything to do with Building Regs it depends on the opinion of the Building Inspector.

I've always accepted it, as far as I know so do all the others I've worked with, and its always been accepted on all the guvvy jobs I've submitted with a similar detail.

[Mr Punter]

Thanks @Ian.  I do feel that fire safety is an important topic and it would be better if this was not left up to the opinion of BC but was something that could be relied upon to comply.  I can understand opinion on site matters with things like foundation trenches, because ground can be variable, but a steel beam is something that could be assessed at plan check.

[juncopartner]

3 minutes ago, Mr Punter said:

but a steel beam is something that could be assessed at plan check.

The only problem for BC is that around half the domestic apps are on building notices these days, so a plan check isn't always carried out.

[Ian]

2 minutes ago, Mr Punter said:

Thanks @Ian.  I do feel that fire safety is an important topic and it would be better if this was not left up to the opinion of BC but was something that could be relied upon to comply.  I can understand opinion on site matters with things like foundation trenches, because ground can be variable, but a steel beam is something that could be assessed at plan check.

Most people (even many building professionals) don’t realise that the published Approved Documents (AD) are simply non-statutory guidance. The actual regs are the short extracts printed in green at the start of each AD. The Building Inspector has wide ranging powers to accept variations to the AD guidance and on large commercial projects it’s very common that alternative solutions are adopted that satisfy Part B - usually to the design of a specialist fire consultant.

[Mr Punter]

Thanks both.  I have a project at present where the architect has specified intumescent paint to beams in a ceiling with 2 x 15mm plasterboard.  We need 60 mins but architect insisted.

[juncopartner]

2 minutes ago, Mr Punter said:

Thanks both.  I have a project at present where the architect has specified intumescent paint to beams in a ceiling with 2 x 15mm plasterboard.  We need 60 mins but architect insisted.

What is the use of the building.

[Mr Punter]

1 minute ago, juncopartner said:

What is the use of the building.

 

3 flats - 1 per floor.

[juncopartner]

Just now, Mr Punter said:

 

3 flats - 1 per floor.

1 hour, looks like he's correct.

[nod]

2 minutes ago, Mr Punter said:

Thanks both.  I have a project at present where the architect has specified intumescent paint to beams in a ceiling with 2 x 15mm plasterboard.  We need 60 mins but architect insisted.

Exactly 

Most of the large commercial jobs I tender for 90 minutes protection is specified for the tender 

So googling would make no difference We follow the spec 

which can vary 

 

Getting to my original point 

Single and two story are fine 

Anything over The beams need 60 minutes protection

 

We are all on here to help with advise Not to trip each other up 

It’s quite common on other forums to have some fool with little to offer sitting waiting to try and trip people up 

Certainty not the norm on here