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chris42  
#1 Posted : 15 March 2021 12:02:30(UTC)
Rank: Super forum user
chris42

Hi all

The RRFSO:2005 requires in section 17.1 requires maintenance of any facilities, equipment and devices. Then in BS 8210:2020 recommends a structural survey of the external fire escape of no more than 5 years as well as regular maintenance checks.

We inspect our exterior stairway regularly for damage, corrosion, stability of the handrails etc and carry out any maintenance if needed. However, if there is no damage or corrosion or other obvious defects on these regular checks, why would you need a structural survey? It is not as if metal rusts from the middle of the inside out, or a structural engineer is going to Ultrasonically test the welds and steel plate etc and redo all the calculation of its strength! So I’m struggling to see the point.

The BS 8210 “Recommends” it is done but this is not an absolute legal requirement (unless it is somewhere else).

Do those of you who have these get a structural survey every five years, and know if it is a legal requirement from anywhere else?

Thanks

Chris

peter gotch  
#2 Posted : 15 March 2021 13:33:36(UTC)
Rank: Super forum user
peter gotch

Chris

Like most things exactly what is required is not set in stone (or in the case of your external fire escape, probably another material).

Some of the principles that you might consider are set out in CS 450 Inspection of highway structures (formerly BD 63/17) which is a free download from the internet.

So, amongst other things you need to consider whether it is safe from a structural surveyor/engineer to do the job. Depending on what they see whether from a safe place such as the ground or close to elements of the fire escape they might want to do some testing, including hammering component and possibly non-destructive testing.

P

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Dazzling Puddock on 16/03/2021(UTC)
paul.skyrme  
#3 Posted : 15 March 2021 13:58:16(UTC)
Rank: Super forum user
paul.skyrme

Is there any hollow section, e.g. tube, square or rectangular "box" section or similar materials that could trap or pool water internally?

Much NDT is done on pipework and vessels in the process industry as they can corrode from the inside out.

If the stairs are fabricated from flat plate, then I fail to see how they can possibly corrode from the inside out.

I would check the documents that have been suggested, other information might be available from CIBSE, or ISructE.

However, NDT guidance would likely come from the BINDT (Home (bindt.org))

chris42  
#4 Posted : 15 March 2021 15:12:33(UTC)
Rank: Super forum user
chris42

Thanks Peter and Paul

I’m not sure you can realistically compare a fire escape going up one level to a bridge carrying HGV’s and buses etc with constant vibration from traffic. I note the referenced document actually lists 72 months (6 years) between inspections for bridges.

Oddly in a previous life I was the Quality Manager for a company that made bespoke steel girders for bridges (and put them up). There are 3 types on NDT (non-destructive Testing) MPI where a white background is sprayed on a welded joint and a water Iron filing solution sprayed on and a magnet across the two pieces to highlight cracks, but you end up with white paint everywhere. The other method is UT and you need close contact with the metal to look for cracks or voids (so would be best to remove the Galv or paint, it can be done through, but is not so good to do, unless just thickness checks).

I really do not think that a structural engineer would do this on an inspection of a stair way. That only leaves the 3rd method of Visual, and my eyes work as well as theirs. Even for bridges you would not carry out NDT unless a visual noted something out of place. You would check bolts (are still there and possibly that they had not come loose).

Fair Point Paul about things like box section, however in this instance there are no hidden sides, it is I section with plate steps.

However, we digress, so back to the question I do not see the point of getting a structural survey after 5 years (and then what wait another 5 years or like a car MOT every year after that). So, is it absolutely necessary or is it so standard practice everyone is doing it regardless or is it just gold plating the need to ensure it is in an efficient state?

I guess a second question to those that have had this done at their places of work, what did they do was it just visual?

Chris

peter gotch  
#5 Posted : 15 March 2021 16:17:09(UTC)
Rank: Super forum user
peter gotch

Chris - the guidance that I referred to applies to all sorts of structures including specifically gantries and their accesses, where the guidance defers to IStructE guidelines.

So, not just structures subject to very high vehicle loadings and I have personally investigated two accidents in which people fell through metal walkways. In each visual inspection would probably have been enough to indicate that there was an issue requiring attention before you needed proof via Non Destructive Testing, BUT there would always be someone who would ask something like "Well, what proportion of the fixings need to have actually disappeared before we think, do we need to NDT the rest?"

Neither of those walkways would fall within the remit for the roads and bridges guidance to which I referred but exactly the same principles apply, and on a steel plate fire exit, there is always the possibility of water getting into e.g. hollow guard-rails, so these COULD rust from the inside. If a guard-rail gives way when 100s of people are trying to escape questions will be asked.

As you indicate, the guidance from Highways England and its counterparts in three other nations indicates that "Principal Inspections" should generally be done at 6 year intervals, but with scope for changing that frequency based on a risk assessment.

Similarly that guidance enables a decision NOT to follow all the technical specification of what a Principal Inspection (PI) should include. As example, a PI should usually involve inspecting all elements of a structure from within "touching distance", but the latest guidance recognises that sometimes that may involve significant risk e.g. of work in confined spaces, which might be avoided at least for some inspections by using remote methods of inspection.

You can change the frequency of inspections done for the purposes of the Fire Order, just as you can change the timetable for thorough examinations of lifting equipment or pressure vessels.

All you have to do is justify why you are not going with the guidance available, or sometimes, where there are factors that suggest every X months is insufficient why you have not done more. 

Guidance evolves over time but usually the numbers have been chosen to provide what is considered by the relevant discipline specialists to present a sufficiently conservative position e.g. to recommend "quinquennial" inspections of building structures. I am not competent to say that the structural engineers are over conservative.

Roundtuit  
#6 Posted : 15 March 2021 16:30:03(UTC)
Rank: Super forum user
Roundtuit

The skill lies in the qualified eyes (underwritten by Professional Indemnity).

What could appear to be a minor crack in surface concrete you would filler over at home could be a major rupture arising from reinforcing bar / plate rust bloom requiring further investigation.

Roundtuit  
#7 Posted : 15 March 2021 16:30:03(UTC)
Rank: Super forum user
Roundtuit

The skill lies in the qualified eyes (underwritten by Professional Indemnity).

What could appear to be a minor crack in surface concrete you would filler over at home could be a major rupture arising from reinforcing bar / plate rust bloom requiring further investigation.

chris42  
#8 Posted : 15 March 2021 17:07:04(UTC)
Rank: Super forum user
chris42

Well not hundreds, it is a secondary means of escape and not likely to be the first choice as there is a protected internal escape outside their office and straight outside at the bottom. They could use it, all 3 of them (well actually 2 but there could be a visitor like me). Worst thing is we are moving in 9 months, and it is anticipated the landlord will flatten the current structure and develop the site.

However, ok then people seem to be saying yes required (even though the BS states recommended).

Interesting thought. If you did not do it and the fire brigade made a visit or HSE, and the stair was actually structurally sound, would they have to prove it wasn’t or would lack of survey to prove it is, be sufficient for some sort of enforcement action.

I have tried to google someone who can do it and they all seem (only 2) offer a repair or replacement service after survey. mmm I would prefer someone to just provide the report so no vested interest one way or another.

Thanks all, makes a change from Covid

Chris

peter gotch  
#9 Posted : 15 March 2021 19:29:54(UTC)
Rank: Super forum user
peter gotch

Chris, that is a completely different Q!

A regulatory inspector would be very brave to take enforcement action merely on the basis of a recommendation.  I would expect them to be looking for some evidence of structural weakness, taking into account the loading that might be reasonable to expect.

P

chris42  
#10 Posted : 15 March 2021 20:47:50(UTC)
Rank: Super forum user
chris42

Thanks Peter

I think it is the same question, is the requirement in BS 8210 a legal requirement in effect, to every 5 years get a structural engineer to survey. Ie the same as an ACOP is considered to represent the legal requirement of legislation in simpler terms and where you would need to do as it states or prove you have done better.

Or is the BS considered to be that of guidance which you can decide to do or not. I my view with our structure, I’m not convinced it is necessary, but you all have made some valid points.

Unfortunately, recently and I don’t just mean covid, the lines of what is or is not a legal requirement seem to be getting ever more blurred.

Chris

peter gotch  
#11 Posted : 16 March 2021 16:40:54(UTC)
Rank: Super forum user
peter gotch

Hi Chris

Still think that it is two QQ!

Base my thinking on spending the first third of my H&S professional career (though there was life before then!) working for the HSE as a regulator and the other two thirds advising the regulated.

So, looking at this with that HSE hat on, then I think that it would be unwise for a regulator to attempt enforcement action without some real evidence that the staircase might be unsafe.

With my other hat and my original assumption that the first question might be about arrangements to last perhaps a decade or more then my advice was to defer to the discipline specialists. So, if the considered opinion of, in this case, the structural engineering community, is inspections every 5 years, you would want to be looking for clear justification to ignore their advice.

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chris42 on 17/03/2021(UTC)
achrn  
#12 Posted : 17 March 2021 12:29:43(UTC)
Rank: Super forum user
achrn

OK, with my professional hat on (as a chartered civil engineer who works on structures, so I'm CEng MICE and specialise in structures, but I'm not a chartered member of the IStructE), I observe:

Engineering is a profession in the technical sense, so is self-regulating as to who 'makes the grade'...

but, Structural Engineer (or indeed Engineer) is not a protected title, so anyone can call themselves a structural engineer, they don't need to have any particular qualification.  As such a requirement that it be inspected by a structural engineer is a rather toothless requirement.

The relevant qualification is the 'CEng' postnomials, but that's just chartered engineer (registered with the Engineering Council), so could be a different sort of engineer entirely (Chemical, Aeronautical, etc).

If you're going to appoint an engineer you probably should appoint a qualified one.

Yes, pretty much anyone being careful shoudl be capable of spotting the defects that an expert engineer would spot.  The difference would relate to the interpretation of the significance of a defect.  For example - a ripple in a flange tip.  An expert should be able to decide if a rippled flange is a big deal or not.  That would depend on quite a lot of things more than just how big the member is and how big the ripple is.

I wouldn't use NDT on a fire escape as described.  The only time I've used NDT on anything similar was where it had circular members and we didn't know how thick the walls of the tubes were, so used ultrasound to measure.  (Answer: they weren't tubes, they were solid round!). Otherwise when inspecting you use NDT when there's a known problem and you're trying to quantify it (e.g. you know you've got a fatigue problem, now you're hunting for actual fatigue cracks). (For this sort of structure - bit different if you're inspecting e.g. the cables on the Severn Bridge, then you'd do a bit more than give it a quick shufty).

For a structure as described, I would expect an engineer will just do a visual and hand-tools measurement inspection.  An inspection is not an assessment.  If you have inspection records and an assessment on record and the new inspection does not identify any new defects, I would not expect to re-calculate anything every five years.

I wouldn't use any BD or their successors.  This whole suite of docs is by the Highways Agency for use on highway and related structures.  There are similar highway structures (metallic footbridge, for example), but you just wouldn't use these docs for that. (Unless you were desperate and a HA doc addressed some situation that no other guide addresses - this is true with respect to some structural forms, notably jack arches on metallic beams).

5 years is a good general rule-of-thumb for building inspections.  It comes up a lot (lots of church  denominations mandate a quinquennial inspection of premises, for example).

I wouldn't do this job - my firm generally only works on larger projects or more specialist things. 

I don't believe it's a legal requirement.  I think it is clearly just a 'recommendation', but I happen to think it's a reasonable one, and something that will bite you if it's not done and 'something' happens. If you got a local Structural Engineer to do it, it shouldn't be too expensive.  It's not much more than 'giving it the once over' with an expert eye and writing a report saying so, if the condition is as described and the design is either reasonably new and OK pretty much by inspection, or you have an assessment of adequacy on record.

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chris42 on 17/03/2021(UTC)
chris42  
#13 Posted : 17 March 2021 19:25:49(UTC)
Rank: Super forum user
chris42

Thank you both Peter and Achrn.

Very interesting. So, both feel it is not a legal requirement, which I agree. However, it does appear to have some quasi-legal standing if you have to prove to an authority why you didn’t follow it, appears to give it an almost ACOP status. Obviously, it will probably prove more difficult and expensive to defend not doing it, than actually just buckling under. Is this how gold plating happens to requirements? Just musing.

Interestingly I did a google search for someone to carry out such an assessment and found only two company’s that advertised as doing this (looked in the Bristol to Swindon area) but I think the results were wider than that. However, both companies offered to fix whatever they found wrong, almost predetermining they were going to. You would have thought that with so many fire escapes around there would be lots of companies offering such a service.

Yes, I agree with your comments regarding NDT and they would generally just carry out a visual inspection. I started my career as a mechanical engineer (and sometimes wonder why I changed), so not a structural engineer, but understand a lot of the structural issues and effects. You reminded me of my years in the heavy steel construction industry, with your comments about flange ripples. Very important issue especially where there were bolted connections which rely on friction between the flange and plate to make the joint.

It is always the small details that make the difference, so the smallest blemish could be a problem. I remember being taught about stress cracks back in the day, and the example of the Liberty ships, which suffered from stress cracks in the square corners of deck hatches. This resulted in some of them actually splitting in two (there were some other factors as well). But enough of memory lane and back to real world.

Thanks again for your input.

Regards

Chris

achrn  
#14 Posted : 17 March 2021 22:10:23(UTC)
Rank: Super forum user
achrn

Originally Posted by: chris42 Go to Quoted Post

Interestingly I did a google search for someone to carry out such an assessment and found only two company’s that advertised as doing this (looked in the Bristol to Swindon area) but I think the results were wider than that. However, both companies offered to fix whatever they found wrong, almost predetermining they were going to. You would have thought that with so many fire escapes around there would be lots of companies offering such a service.

https://www.istructe.org/find-an-engineer/structural-engineers-near-me/

Although somewhat targeted at domestic clients, this may find you some more local smaller firms.  IStructE members will be very unlikely to do repair work, so it elminates that potential conflict.

(As noted, you won't find me in that list, so I'm hoping no-one interprets thsi as advertising).

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chris42 on 18/03/2021(UTC)
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