Update: You could be excused for thinking that everything is falling down

I saw a catastrophic failure waiting to happen during a drive through New Brunswick a few days ago (September 26, 2020).  A barn roof that was sagging a good 10 feet in the middle.  For sure, a barn that was no longer in use because of the risk.

Of course I added it to the list of failures I posted last July 23 that are everywhere in the built environment. (Ref. 1)

It was the magnitude of the sagging ridge that caught my eye. Even at a distance it was easy to imagine, maybe just see the bulging eaves. The eaves of a roof bulge out when the ridge sags.

You see lots of large and small buildings in the country with roofs that are sagging a little or a lot.  Many are abandoned, but not all. And some are only a few years old, not gray with age and many decades old.

You can also see buildings in town – houses, for example – with sagging ridges. A tiny sag, a few inches at most, just enough to catch your eye from the street.

The large sags are probably due to inadequate design of the roof trusses or the rafters. Many of the tiny sags are design failures too.

But some tiny sags are due to green lumber shrinking as it drys after construction is complete. This is a planning failure because less suitable green lumber was accepted for building design and construction.


  1. You could be excused for thinking that everything is falling down. Posted July 23, 2020 (Scroll to July on the right of the blog page and see Item 9 in Section C. Large and Catastrophic Failures)

(Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia. ejorden@eastlink.ca)

Update: Principles governing the cost control of dispute resolution and claim settlement involving experts

I updated the Principles after being contacted by a Toronto firm about a slip and fall accident. The question came up about being retained on contingency. The contact said they do this when the injured party may have a claim but no money to pursue their rights. He also thought the claim would settle within a year. I told him I couldn’t do this.

The chap was pleasant but I thought later, after he remarked he was acting for a partner in the firm, that he may have been a more junior member of the firm and just didn’t know: Experts don’t take cases on contingency, and slip and fall cases typically take more than a year to settle.

Common law requires that experts: (Ref. 1)

  1. Be independent from the parties that retain them
  2. Provide objective, unbiased opinion evidence in relation only to matters within their expertise, and,
  3. Avoid assuming the role of advocate for the parties that retain them

These requirements are the same in all issues involving dispute resolution and claim settlement. The great majority of experts know that they serve the process, as found in a pilot study of 152 Canadian experts, not the party who retained them. (Ref. 2)

The requirements also mean that an expert must engage on a fee basis not on a contingency basis.

But, to be absolutely sure that there wasn’t another school of thought out there on experts and contingency I contacted the head of another Toronto law firm. I haven’t been answered – slammed would be more correct – as quickly as in this case: “Absolutely not!”.

After all this, I thought, I better update the Principles to be sure it’s clear when managing cost that experts are not retained on a contingency basis.

You can read the updated Principles at http://www.ericjorden.com/blog/2019/07/30/principles-governing-the-cost-control-of-dispute-resolution-and-claim-settlement-involving-experts/ as originally posted on July 30, 2019.


  1. Stockwood, Q.C., David, Civil Litigation, A Practical Handbook, 5th ed, 2004, Thompson Carswell
  2. Corbin, Ruth M., Chair, Corbin Partners Inc. and Adjunct Professor, Osgoode Hall School, Toronto, Breaking the Expert Evidence Logjam: Experts Weigh In, presented at Expert Witness Forum East, Toronto, February, 2018


  1. Jorden, Eric E., Consulting professional engineer; forensic engineer, Geotechnology Ltd., Halifax, Principles Governing the Cost Control of Dispute Resolution and Claim Settlement Involving Experts, presented at the Expert Witness Forum East, Toronto, February, 2018

(Updated September 23, 2020 by Eric E. Jorden, M.Sc., P.Eng, Halifax, N.S. Canada.  E: ejorden@eastlink.ca)

Get on site and do a forensic visual assessment before COVID-19 returns

There’s an argument for getting on site and doing a visual assessment before COVID-19 returns. There is talk of a second wave. I thought this when I was thinking of getting up to New Brunswick to visit friends before I get COVID-19-stayed in Halifax for the winter.

There’s no question about the value of virtual site assessments as I noted recently. (Refs 1, 2) Studying emailed documents and photographs of a site and getting a lot of data without leaving the office. Including the cause of a slip and fall accident that stared me in the face recently. (Ref. 1)

But, the worth of an on-scene visual assessment has been well understood for decades – if it can be done safely. Pre, second-wave COVID-19 would be safe. (Ref. 3)

Getting on site would give us:

  • additional photographs to those in the documents,
  • aerial video – pre-planned with a virtual drone flight (Ref. 4),
  • accurate measurements,
  • re-enactment of a slip and fall accident, if that’s the issue,
  • a forensic engineer calibrated to the site (Ref. 5), and,
  • more hard data for continued virtual site assessment back in the office.

In many cases, a forensic investigation unfolding in this conventional way – document study then an on-site visual assessment – often points to the cause of a problem and those responsible. And often, as well, to how an insurance claim might unfold or whether a civil case should be filed. Additional intrusive investigation at the scene is sometimes needed but not always.

So, what are we waiting for? If a second COVID-19 wave is in the wings ready to wash over us, and we quickly visit friends in the Atlantic bubble to get ahead of it, why aren’t we quickly doing an on-site visual assessment?


  1. What can you get from a virtual visual examination of an accident scene? Posted August 28, 2020 2. It’s here
  2. COVID-19 and forensic engineering investigation. Posted May 7, 2020
  3. COVID-19 and an initial forensic task a.k.a a visual site assessment, sans social distancing. Posted June 1, 2020
  4. It’s here, cost effective, efficient aerial video for forensic investigation! Posted October 8, 2019
  5. Can you “calibrate” a forensic expert? Posted June 23, 2020

What can you get from a virtual visual examination of an accident scene?

In these COVID-19 times, why not “stay home”, as we’re told, and do a virtual visual examination of a failure or accident scene? Simply read the documents and study the photographs then hypothesize cause, at least initially.

Recognize the document study for what it is, a virtual visual examination, and accept it as a quite valid task in a forensic investigation. At least in the short term, in the interest of staying safe.

There’s no question a lonely expert can still go to a scene and do a visual examination, get a wealth of data and be quite safe. (Ref. 1) It’s just that a virtual visual examination of a site is good in the beginning too, can sometimes, unexpectedly, see the cause, and is less expensive.


I thought this recently when I was contacted and read the emailed documents on a slip and fall accident and studied attached photographs. I realized this was a virtual visual examination of the scene. The probable cause of the accident was obvious in this case. The party responsible was possibly lurking in the wings, virtually visible too.

It was also easy to identify the three field tasks that would need to be done during a complete forensic investigation of the slip and fall and the data that would be got from each. Also a fourth office task.

  1. Visit and visually examine and measure the accident scene for real, and take more photographs – and also get calibrated to the scene as I blogged recently (Ref. 2)
  2. Examine construction of other similar facilities in the area
  3. Re-enact the accident at the scene
  4. Assess the standard of care in the office for design and construction of similar facilities

So, the cause, the parties involved and the tasks necessary for a full scale forensic investigation. All this from a document review – a virtual visual examination of the accident scene without leaving the office.

It’s a way of thinking in keeping with these COVID-19 times.


  1. COVID-19 and an initial forensic task a.k.a a visual site assessment, sans social distancing. Posted June 6, 2020
  2. Can you “calibrate” a forensic expert? Posted June 23, 2020

Why the surprise about the mud slide in BC?

I was surprised that a house was built in the path of the mud slide in British Columbia early this month, July 4th.  Built right in a mud channel.  Particularly in view of the fact that the Ministry of Transport reported that more slides were possible – they knew. (Ref. 1) Why were houses approved for construction in such an unstable area?  Who is liable?

Assessing the potential for a mud slide in an area and quantifying the risk for residents is not rocket science.  Someone had done sufficient assessment to warrant the report of the Ministry.

You don’t see the messy stuff mentioned as such in engineering books but it’s there.  It’s classified as very soft clay and silt with a little sand and gravel and a few cobbles.  The analytical procedures are in the books too – reliable slope stability methods of analysis understood by experienced engineers.

So, what’s the big surprise about the mess in BC and why were people allowed to build there?  We’re not talking something small here.  We’re talking about a slide that engulfed a house to a depth of several feet according to pictures on line.  And moving fast too as seen in one video of a fellow running out of the way just in time.

You don’t need a lot of data to do such an analysis either and the data is readily available in the public domain:

  • The history of mud slides in the area and the rain fall at the time
  • Topographic maps to give you the shape and slope of the ground, and the location of mud channels
  • The results of terrain analysis identifying features relevant to mud slides, and evidence of past events (screen grabs from video taken from low flying drones has had a big impact on the engineering analysis of terrain in an area)
  • Soil maps (surficial geology maps) to tell you that a mixture of clay and silt underlies the area

Engineers have done this type of assessment often, and everywhere throughout North American and around the world.  And based on the news and Transportation’s report, likely for this area as well.

So why the surprise?

Why would a person even mistakenly build a house in a mud channel?  I can’t help but think there would be local knowledge that would kick in even if the government was silent.  Would you build a house in a river channel or on a flood plain between wet seasons?


  1. Notes taken from a CBC News report online.  “Debris flood, a mix of mud, gravel and cobbles 200 km east of Prince George, BC in a flood prone area 1:30 Saturday morning July 4, 2020.  Waist deep.  Second one that day nearby.  Ministry of Transport said more likely in the area”

Can you “calibrate” a forensic expert?

What happens when we calibrate something, and can the procedure apply to a person?  For example, a forensic expert?  Does it happen unbeknownst to an expert?

I said in a recent blog that this happens to an expert when he visually examines the site of a failure or accident in the built environment – he gets calibrated to the site. (Ref. 1)

Then I began to think about it.

This description of a visual examination came to me when I remembered hearing years ago about an American engineer asking to have some pits dug at a site that he was visually examining in Newfoundland, so he could “…get calibrated to the site”.  The phrase resonated with me at the time.

This was George F. Sowers, a professional engineer with an international reputation in foundation and geotechnical engineering. (Ref. 2)  All of us in this field of practice knew of him.  This was a serious foundation problem if Dr. Sowers was called in.

Still, I thought, I better check the meaning of calibrate in the event Dr. Sowers stretched it a little.

The Merriam-Webster dictionary gives several definitions of calibrate, one of the last in a list of five is most applicable to Sowers use of the word:

“…to adjust precisely for a particular function, e.g., calibrate a thermometer”

Sowers was getting himself adjusted precisely to the site so he could function in a particular way – as the forensic engineer investigating the cause of the problem at this particular site.

You might say this is wandering away from a dictionary’s meaning. (Ref. 3)  I don’t think so.  One thing I’ve learned blogging on the nature and methods of forensic engineering in the past eight years is that words are taking on new shades of meaning all the time.

Using the word calibrate in a recent blog to describe what happens during a visual site assessment just came out of me from deep down inside.  It was natural.  Also knowing it was used this way by a quite reputable and experienced engineer years ago.  And it’s supported by Merriam-Webster.

The word calibrate does suggest preciseness, and that’s a big element in a visual assessment of a site – you can’t plan a forensic investigation of a failure or accident until you’ve seen the site.  Think, a picture (seeing something) is worth a 1,000 words.

Can you “calibrate” a forensic expert?  Yes.  It happens as a matter of course when s/he does a visual assessment of a site before commenting on how to determine the cause of the accident or failure, if more investigation seems necessary.


  1. COVID-19 and an initial forensic task aka a visual site assessment, sans social distancing.  Posted June 1, 2020
  2. Sowers, George F., Introductory Soil Mechanics and Foundations: Geotechnical Engineering, 4th edition, MacMillan Publishing Co., Inc, New York
  3. Family Word Finder, A New Thesaurus of Synonyms and Antonyms in Dictionary Form, 896 pg. Reader’s Digest in association with Stuart B. Flexner 1975




Drone photography continues to soar to new uses in forensic investigation

Why do we need terrestrial photography in forensic engineering investigation – ground level photography with hand-held cameras – when we have drone photography?  Aerial photography that can capture the same images from all directions, heights and angles plus distance and close-ups.  And software that can give you numerical values for these quantities?

And more software so you can plan a virtual flight over and around the accident or failure site before you even go there. (Ref. 1)  Then tweak the flight based on what you find after you get your boots on the ground?

Why bother with the expense and incomplete coverage of ground photography when aerial photography can do almost all of it?  (Ref. 2)

These thoughts came to mind during the most recent meeting of CATAIR in Moncton on March 13, 2020 and a talk and demonstration of drone photography by Robert Guertin of Millenium Film & Video Production, Dartmouth, NS.

The CATAIR meeting – the Canadian Association of Technical Accident Investigators and Reconstructionists – was attended by members representing the police, private sector and professional engineers who investigate accidents and failures in the built environment.

Robert described drone photography and what it could do, explained and showed how the equipment has evolved since about 2008 – when drone photography took off – and then demonstrated by flying over the parking lot outside.

My ear caught a remark by one about using drone infrared photography to spot hot spots on the ground during forest fire fighting.  I thought, that’s one more use of drone photography that I can add to my list.

I learned some time ago about farmers flying drones over their crops.  I can imagine crop flying as an excellent use of terrain analysis.  For example, an easy way to learn what areas need irrigation rather than spending money irrigating the entire crop.

I understand drones are being used out west to actually water crops.  Still another use.

The “terrain” being analysed is the top of the crop from a height of a few 10s of feet for what looks dry and what looks okay.  I’m not certain if that’s what’s happening but it could.

I’ve been using drone photography during my forensic investigations for about five years now.  On problems as diverse as:

  • the effect of retaining wall construction on the flooding of a property,
  • determining the presence of fuel oil contamination on new and old sites,
  • assessing road safety,
  • staging a potential traffic accident,
  • collecting data for drafting a topographic plan of a forensic site,
  • re-enactment of a traffic accident – a colleague did this recently.
  • In a sense, I did it years ago during my investigation of the John Morris Rankin accident.  But in this case from the top of a 100 foot high boom supporting the camera man – the “drone” – with a hand-held camera.  I also flew the site of the re-enactment in a sea king helicopter – a large drone?
  • increasing the effectiveness and reducing the cost of a conference call using a DVD of a previously drone-flown site distributed to each participant, (Ref. 3)
  • the potential in the re-enactment of a nail gun accident – I got “aerial” video with my cell phone by reaching high while standing on my toes, but a drone flying 10 feet up would be better – next time, and,
  • the quite unbelievable potential for determining the cause of large cracks in the wall of a recently constructed multi-story building – if only the parties had got to me.

To give terrestrial photography it’s due, considering it has served forensic engineering investigation well for decades, drone photography is restricted to light winds, dry weather and open scenes.

As long as s/he’s dressed for it including dry boots and his camera protected from the weather, the eye-level, ground photographer can plant her boots anywhere, in any kind of weather and in any tight nook and cranny and get the shot.  Including underwater.

Low level drone photography does have it’s limits like terrestrial photography but it has taken off with new uses appearing all the time on the forensic engineer’s plate.  Today, I would not investigate the site of a personal injury, like a slip and fall accident, or a component or catastrophic failure in the built environment, without getting aerial video from a drone.


  1. It’s here, cost effective, efficient aerial video for forensic investigations!  Posted October 18, 2019
  2. A Bundle of Blogs: Aerial video of insurance and forensic sites taken with camera mounted on drones.  Posted October 31, 2019
  3. Conference call on a “drone flight” reduces the cost of civil litigation.  Posted May 18, 2017

It doesn’t rain but it pours guidance on writing expert reports

I thought this on reading the guidance for presenting a claim in the Small Claims Court of Nova Scotia.  I was researching material to do with a case at the time.  You can read the simple guidance at www.legalinfo.org

Experts could do worse than visit this site for more guidance on carrying out a forensic investigation, analysing the results, forming an opinion on cause and presenting their findings in an unbiased, objective expert report.  This is particularly the case when it comes to writing the expert’s report – which has been found wanting. (Ref. 1)

The guidance at this web site states that you need evidence to support a claimEvidence is anything that helps prove a fact important to your case.

Eureka! How is this any different than the evidence needed to help prove the facts supporting your opinion on the cause of a personal injury or a failure in the built environment?

Also quite important in the guide is the note that when you testify in court you’re telling your story.

Keep the forensic story, like the testimony in court, evidence-based, jargon-free and simple:

  1. Tell ’em what you’re going to tell ’em
  2. Tell ’em – with a beginning, a middle, and an end
  3. Tell ’em what you told ’em

It’s nice how simple guidance on preparing a claim for Small Claims Court can help us carry out well substantiated forensic investigations and write evidence-based expert reports.  Realizing guidance is needed (Refs 1, 2 and 3) and that there’s detailed handbooks out there (like Ref. 4) should be enough.  The Court’s guide is more of a reminder – a gentle rain rather than a down pour.


  1. Is there an argument for a peer review of a peer review?  Posted January 11, 2020
  2. Ridding peer review of potential bias.  Posted December 30, 2019
  3. What good are civil procedure rules governing experts?  Posted January 30,2020
  4. Mangraviti, Jr., James J., Babitsky, Steven and Donovan, Nadine Nasser, How to Write an Expert Witness Report, 2nd ed, 2014, 560 pg, SEAK, Inc., Falmouth MA, USA

What good are civil procedure rules governing experts?

Particularly if most disputes don’t go to trial or a tribunal?  But, isn’t that the purpose of the rules, to keep disputes out of court?  Like Rule 55 in Nova Scotia?  That’s true, and they do this by setting a high standard for an expert report.  The parties, on reviewing the report, would often enough see their way clear to settle.

However, I wonder if a lower standard of report is now being accepted?  Why pay for a higher standard if the dispute is unlikely to go to trial or a tribunal?

The standard appears to be lower in the Maritimes if a survey I did of seven engineering experts in NS and NB is any indication.  I asked them, To what extent do you see bias and poor analysis and reasoning in rebuttal expert reports?”.  The consensus was almost always. (Ref. 1)  I’m certain, the question could be asked about expert reports, in general, and the reply would be similar.

(I wonder if the bias and poor reasoning we see in some expert reports in the Maritimes appears in some of the reports of the experts surveyed in Ruth Corbin’s pilot study of 152 experts in Canada?  The study noted the expert’s view of their role in the judicial process. (Ref. 2))

The civil procedure rules are a short, simple guide on carrying out a forensic investigation and writing an expert report, but what good are they if they’re not followed?

And why aren’t they?  Cost?  Possibly.  An understandably, poorly informed non-technical client?  Likely.

I don’t think the rules are going to be taken down any time soon.  I think what’s expected of the expert must go up.  This must come to some extent from a better informed client about the benefits – including cost-benefit in the long run for both client and injured party – of a thorough investigation and a well written, objective expert report.

What’s being submitted now for expert reports and rebuttal expert reports are easily reviewed by unbiased, experienced technical experts – easily “slammed!” to use an expression by one of my survey experts.

(I’ve got a problem with that word “slammed” as reflecting an attitude at odds with a simple desire to seek the truth when peer reviewing another’s expert’s report.  But, it does indicate what can happen to a poorly written report)

What are the benefits to the expert and the client of following the rules for likely out-of-court settlements?  I think the following quote is a good answer:

An expert’s report is a critical, make-or-break document.  On the one hand, a well-written report will make testifying later at discovery and trial much easier (if it goes that far, and pre-trial decision making more reliable) and will enhance the reputation of the expert.

On the other hand, a poorly written report will damage the expert’s reputation, can turn deposition into a nightmare, and can become a career-ending event (and an out-of-court settlement or dispute resolution into something less than fair for some of the parties)” (Ref. 3) (The parenthetic comments are mine)


A little aside.  What’s in Ref. 3 – How to Write an Expert Witness Report – for counsel and insurance claim’s managers if you were to buy it – which I think you should?  Maybe even give a copy to your expert?

This 2nd edition, massive, 560 page, 8″ x 11″ book is a step-by-step guide for experts written by lawyers.  It’s based on a review of 1,000s of expert reports, case histories and insurance settlements.  It will give you great insight into what you should be getting for your expert-report dollar.  It’s far more comprehensive than civil procedure rules governing experts, as good as they are.

(This is not a commercial for the book.  I use it and it’s excellent!)


  1. Is there an argument for a peer review of a peer review?  Posted January 11, 2020
  2. How experts are helping break the expert evidence logjam. Posted April 30, 2018
  3. Mangraviti, Jr., James J., Babitsky, Steven and Donovan, Nadine Nasser, How to Write an Expert Witness Report, 2014, (the Preface), 560 pg, 2nd edition, SEAK, Inc., Falmouth MA


Is there an argument for a peer review of a peer review?

I wondered after a recent blog if there is an argument for a peer review of a rebuttal expert’s report. (Ref. 1) There’s a strong argument, if the evidence is any indication – evidence characterized, at the very least, by biased phraseology in the rebut.

In my blog I identified when peer review of an expert’s report could be done – as distinct from a rebuttal expert’s report – during the judicial and dispute resolution processes, and the involvement of the expert at each stage of a process.

I listed the stages in decreasing order of preference according to the involvement of the expert in organizing a peer review of his report.  The less involved the expert the more preferred the stage.  A peer review organized by the court or dispute resolution tribunal is the most ideal.

I included a rebuttal expert’s report in the list because it can be thought of as a review by a peer of an expert’s report.  I put it at the end of the list as least preferred even though the expert doesn’t organize it.  I did this because of the bias I see in rebuttal reports.

Based on what I’ve seen, and learned from other experts, rebuttal expert’s reports need to be peer reviewed.  A well reasoned and written rebuttal expert’s report can serve as a peer review of an expert’s report but that’s not happening.  They are not being prepared as required according to civil procedure rules governing experts, like Rule 55 in Nova Scotia.

My opinion is based on a survey of seven people in Nova Scotia and New Brunswick who provide expert services.  I asked them, To what extent do you see bias and a lack of analysis and reasoning in rebuttal expert reports?”.

The consensus was almost always.  Sometimes it’s due to sneaky bias that creeps up, unbeknownst, on all truth-seekers.  Other times – too often – it’s due to poor analysing and reasoning followed by poor report writing.  At times it’s blatant case-making for the client.

Also, often enough, the client, not being a technical expert in the issue, is unaware of his expert’s rebuttal report’s vulnerability to peer review.


So, based on a survey of well experienced experts in the Maritimes, rebuttal expert reports are likely biased and poorly prepared and there is a strong argument for peer reviewing them.  And the guidance in civil procedure rules like Rule 55 in Nova Scotia make it easy to do and cost effective.  It costs money in longer trials, longer dispute resolution processes and questionable insurance settlements if a rebuttal expert’s report is found wanting – as most are now.


  1. Ridding peer review of potential bias.  Posted December 30, 2019