What’s worse? A “mining house” or a “sinkhole house”?

Would you prefer a house constructed on ground that’s subsiding or one on ground where sinkholes pop at the surface?  A “mining house” (Ref. 1) or a “sinkhole house” (Refs 2, 3).  And if you had the one or the other, what could be done about it?

I thought this on reading the item in The Chronicle Herald on February 14, 2020 about Pictou County’s “mining houses”.  How an area’s coal mining history can sometimes come to the surface in unwanted ways and how these zones are not always known to home owners and buyers. (Ref. 1)

I would pick a “mining house” on ground underlain by deep mines rather than a “sinkhole house” underlain by Karst terrain – ground prone to sinkhole formation.  That’s because geo-engineers can analyse subsiding ground with some certainty and predict where it will occur and the amount.  It’s not so easy and cost effective to analyse and predict where sinkholes will occur. (Refs 2, 3)

(Geo-engineers – short for geotechnical engineers, a specialty of civil engineering)

Geo-engineers have lots of existing evidence on subsiding ground that they can analyse.  Evidence like the following:

  • The location and depth of the underground mine,
  • When it was worked,
  • The type of ground overlying the mine,
  • The contour of the ground now,
  • The condition of the houses and,
  • Published data on problems like this elsewhere in the world – like in the UK.

This is the evidence that I would gather together and analyse, and tell you a lot after I was done.

There’s also lots of information on this type of problem in the UK where I practiced for three years.


How does a “mining house” problem relate to forensic engineering?

It’s because the problem isn’t too much different from other problems in engineering, including forensic engineering.  You can learn a lot from existing evidence, sometimes very little existing evidence.

I was told about cracks in a building wall one time and the material used to construct the wall – the building was not in mining or sinkhole country.  The cracks had been caulked suggesting they were large enough.  I was not told about the shape of the cracks nor did I see the wall.  But, based on their size and a few years forensic and geo-engineering experience I knew the likely shape of the cracks and the cause.


It’s the same in mining country.  An experienced geo-engineer would examine the condition of the houses on the subsiding ground and beyond, input this to the other evidence and tell you a lot about the situation in the area.  Including where not to build or buy.  That’s possible in Pictou County.


  1. The Chronicle Herald, page A8, Halifax, February 14, 2020
  2. Update: Sinkhole news highlights a problem that can be fixed.  Posted April  8, 2019
  3. Sinkholes: A litigious matter?  Posted September 15, 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