Probes: Destructive Investigation

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PROBES
Destructive Investigation
of Historic Fabric
in the Built Environment
Prepared by: Ken Follett May, 2014

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Table of Contents:
PROBES
03 10 14 17 25
page page page page page
Destructive Probes The Long Talk Teamwork The Envelope RFP
There are 33 slides in this SlideDoc.
They include the title, this slide of
contents and the end slide.

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Destructive
Probes
Non-destructive Testing (NDT) is a
technological phenomenon of great
merit when it comes to non-
interference in heritage fabric.
For good reason it has received a
whole lot of attention and
development. It is some really cool
stuff with usually quite expensive
equipment.
A lesser cousin, less exotic but a
quite traditional approach to gaining
information is to make a hole in the
wall, to make a hole in the historic
fabric.
To put a hole in the wall.
“He got mad because he could not
figure out where the electric conduit
was buried in the wall and in a rage
he swore and kicked the sheetrock.
His work boot put a nasty hole.
That is how we found what we had
looked three days for.”
Compared with NDT a whole
lot less attention in the
preservation industry has
been applied to
improvements in how an
investigation team goes
about destructive probes.
It seems easy enough.

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Why?
Does all of the terra cotta at the
cornice of this building need to be
removed and replaced?
This as-built drawing from 1876
shows a beam here behind this
chestnut panel, but that makes no
sense when I look at the building.
We thought that all of the cast iron
pieces were bolted together until we
got up there and took a closer look.
Forget about it!
We need to know how this beam is
connected into that beam, and there
is a whole lot of concrete fireproofing
in the way.
Stop for a minute and hold
this thought in your head: "I
need to know something, and
I am not really sure what to
do about it."
Why do probes?
Because we have an idea about what we
do not know.

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Why not?
With the well known preservation
mantra "Do No Harm", it makes
sense to do one's best to not
interfere with or potentially cause
damage to irreplaceable and often
delicate heritage fabric.
Indiscriminate use of construction
workers who are not experienced
with traditional materials or building
techniques, or who may not be
informed or sensitive as to the
importance of historic fabric, can do a
whole lot of harm in a very short
period of time.
Before taking anything apart it is
important to have confidence in the
craftspeople who will be using the
tools to touch and play with the
materials.
Not all workers will
understand the importance
and delicacy of the heritage
fabric that they touch.
Why not do probes?
Delicate materials.
"It was not up to us but the owner hired a
demolition contractor to do the probes.
They thought it would be cheaper. You
can see what sort of mess that made.
Can you fix this?"
silk wall covering
silver gate of St. Sophia of Kiev, Ukraine

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To Open a Hole
in the Wall
Noise is not signals we desire to
uncover and reveal, it is the clutter
that hides and disguises what we
look for.
It is the blue paint that we see that
hides the plaster that covers the red
brick that encases the rusted steel
column buried in the masonry of the
wall.
Noise is stuff that we do not want to
hear. It is the chatter that envelopes
the signal that we actually do want to
hear, and we hope that we hear it
clearly.
But if we do not engage with the
environment, if we do not open
ourselves up to all of the noise, then
we may miss the very information
that we need.
Information does not exist in
a vacuum.
It is surrounded by an
environment of noise, of a
whole lot of distraction and
stuff that doesn't particularly
matter.
NOISE: “Hey, do you hear
that orange bird up there in the
branch above the nuthatches?”

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Reality
Unknown information reveals itself
over time, but time is short and
expensive.
What you at first think may
be going on may not be what
is going on at all.
Discovery is the process of
revealing what is not known.

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Theory
An understanding of the structure,
with the background of theory, needs
to be adequately communicated to
the project team in order for
appropriate and optimized decisions
to be obtained by the project team
during the pre-construction design
phase.
The tools that you have as a
preservation engineer
provide a conceptual
framework within which the
structure can be envisioned
and modeled.
Theory needs to be applied
to an understanding of the existing
historic structure, and to how
materials behave over time in the
natural environment.
“...the trouble about arguments is, they
ain't nothing but theories, after all, and
theories don't prove nothing, they only
give you a place to rest on, a spell,
when you are tuckered out butting
around and around trying to find out
something there ain't no way to find
out...There's another trouble about
theories: there's always a hole in them
somewheres, sure, if you look close
enough.”
- Tom Sawyer Abroad, Mark Twain

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B&PI: Bits and
Pieces of
Information
Bevan P. Sharpless (1904–1950)
was an American astronomer. He
concluded in 1944 that the orbit of
Phobos was decaying and reported
his observations at the US Naval
Observatory in the Astronomical
Journal in 1945. A crater on Phobos
is named after him.Do you
remember Bevan?
I just now read that 50% of
our awake consciousness is spent in
daydreaming.
So how do we stay focused the rest
of the time?
He travelled 7,300 miles to
the tiny island of
Niuafoʻou (the name
means “many coconuts”)
to observe and
photograph a total eclipse
of the sun which lasted
only one minute.

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The Long Talk
At the Federal Reserve lobby that
night there was the project architect,
the senior architect, the structural
engineer, the architectural
conservator, the graduate student
“specialist”, the probe contractor, the
lead trade mechanic, and the recent
preservation trade school graduate
who looked like any other NYC
laborer.
The first two hours were spent talking
about the Guastavino Tile vaulted
ceiling that we all looked at. The
question was, “Where do we put the
hole?”
Only fifteen minutes were spent to
set up and for the lead trade
mechanic to drill a 1/8” diameter hole
in a mortar joint.
Communications: Plan, Execute,
Monitor and Control
A vital element of the
success of any project is the quality
of the communications process.
An RFP with a focus on the
information to be obtained does not
necessarily outline expectations that
the investigation team will need all
members to be able to effectively
communicate with each other.
But in any investigation there will be
a need for long talks and less action.

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The Long Talk:
Plan
Imagination builds castles in the air
and then we see the television
advertisement for the fantastic pick-
up truck that shows children looking
out windows in the very best ever
tree-house in the grand old
basswood tree that suddenly, very
suddenly reverses in the short-short
movie and is rapidly un-built before
our astounded eyes into a pile of
boards delivered in the dirt.
When we approach an understanding
of how the built environment was
built, then we need to imagine it in
our mind ten times. We may or may
not have seen this particular detail
before. Was the carpenter left or right
handed? We could have seen it
diagrammed in a book, or we could
have once seen this pattern when we
had a hammer in hand after busting
through a hole in a sheet-rock wall.
Or this could make absolutely no
sense to us at all. Maybe we had
better sleep on it. Better yet, you stay
awake while I go sit in the truck and
watch that it is parked legal.
“Build ten times in your mind.
Build three times on paper.
Build once in the real world.”
John Leeke’s Dad

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The Long Talk:
Execute
“After we had that long talk at the old
house along the Neversink they went
out to their truck and in a few minutes
they came back with an assortment
of tools.
They also brought in protection for
the floors and they took care of a few
things I had never even thought
about.
One of them handed me a dust mask
and ear plugs.
They went to work and did not bump
into each other, despite the space
being very close and tight. It was like
they knew what they were doing.”
It can be very easy to move
quickly in the wrong
direction.
The longer the talk the
shorter the work... if we know what
we are doing.

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The Long Talk:
Monitor and
Control
How will we get the best results from
our efforts?
Everyone needs to be
prepared to stop the motion and talk
about what it is that is going on.
Otherwise things can get squirrelly in
a hurry.

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Teamwork:
Working Together
Bring experienced people together in
a shared adventure of curiosity and
then see what happens.
When I was first hired to be a
foreman on a project and
sent out to lead in the field
my mentor said to me, “ I am
sending you out to work with
people that will know a whole
lot more about what they are
doing than you. Will you be
able to deal with that?”
There needs to be people
brought together as a team, to work
together, in order to have a Long
Talk.
That is, unless we are going to only
talk to ourselves.

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Teamwork:
to Learn
From Each Other
When we work together as a team,
then we all gather together in a
shared environment and learn from
each other.
"Like other men, he gathered
his education as he lived. He
was the creature of his
environment and inheritance,
and his ideas matured
gradually as he learned from
other men and from his own
experience."
Be curious.
Ask stupid questions.

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Team Building In the midst of January it was bitterly
cold in the masonry tower.
We had spent the better portion of
the morning pulling and carrying up
containers of equipment to the top for
the Non-Destructive Testing team.
There were cracks in the stone wall
that needed to be mapped out. We
also moved and held ladders for the
architect.
The kerosene heater was way less
than perfect. We made a few holes
here and there to confirm findings.
What do you think this squiggle here
means? Everyone was cold. We ate
lunch together up there where we
could see our breath as a white
vapor in the chill air. The report was
due the following Wednesday.
When all was said and done at the
end of three days the engineer
turned and said, "We usually use
XYZ for this work, they have a good
crew, but you folks seem to actually
care if we find what we are looking
for."
Who would be best to have
on our team, who has
experience and can share
their knowledge to help us?
.
Do not think in terms of,
"Oh, anybody can put a hole in the
wall.”
Think about who you want to spend
your time at work with.

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The Envelope
The envelope is all of the activity in
the environment that surrounds the
process of the investigation.
Access, permits, insurance,
movement of tools and materials,
parking, weather, toilets, food,
shelter, dust masks, eye protection,
lunch, the public, temporary
barricades, traffic cones, and signals
and signs. Safety harnesses,
eyewear and hard hats. All are
elements of the envelope and they all
need to be managed.
Time, Space, Cost and Politics
It was a very hot day and
the consultant who had been for
several hours out on the stone plaza,
which radiated heat into the air, came
over and sat down with the team
where the ongoing Long Talk was
about next steps.
Suddenly the consultant noticed that
we were all drinking water and he
said, “Where is the water?”
He was sitting on the water jug.

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Time Envelope
The theater site required that we do
our probes between performances
and public use of the building.
We were required to work three days,
then take four off, then return and
work four, then take five off.
It went on like that, and at the end of
each session we had to be all closed
up, cleaned up, and demobilized
from the site.
All this and the design phase
required that we be done with
everything by the last day of the
month.
To put a cost on this was a headache
and three-quarters.
It would all be so much
easier if we could reliabily
use Remote Viewing. That
would be the ultimate in non-
destructive.
The time envelope begins
when the investigation team arrives
on the site and ends when the last
person leaves at the end of the
information collection process.
The preservation engineer will
generally enter into the time
envelope at a point after the start and
prior to the end of the allotted site
time.

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Space Envelope
One space is not like another.
The RFP says that the walls and
walkways need to be protected but
only includes a photo of a portion of
the ceiling with a rectangular box
drawn on it. Caption: ‘Make hole
here.’
When the president of the United
States shows up then you had better
expect that you are now in a different
sort of space.
When the structural engineer
says that they want to poke
their head up through the
ceiling we look at their head
and determine how large of a
hole needs to be made in
order for them not to get
poked or stuck.
We also ask them if they
need a flashlight. We hold
the ladder until they come
back down.
Space is the area of the
physical activity.
Maintenance of logistics and safety,
and supply lines are primary
concerns within the space envelope.
A smoothly functioning team provides
the structural engineer or architect
with the support needed for a focus
on the specifics of the information
collection process.

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Space: Before You
Visit the Structure
Know where you are going, how you
are going to get there and what you
need to take with you, or for others to
be prepared to bring along.
Review the existing documentation.
Drawings: study them if they are
available. Often they are not.
Photos: study them closely.
Previous Reports: share them.
Do not forget Personal Safety
Gear: hard hat, eyewear,
appropriate work boots, ear
protection and gloves.Do you need a harness?
Where is your tape measure?
Camera?
Paper, pen or pencil?

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Space: When You
Visit the Structure
Walk About.
Observation.
The reality may not match the
documentation. You need to discover
the reality.
Ask questions; interview those who
are familiar with the structure.
If you take photographs include the
surrounding conditions. Step back a
ways and capture the entire
envelope.
Observation of Details: Learn
the Value of Sitting and the
Art of Doing Nothing in
Particular.
Look for the unexpected.

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Space:
Site Logistics
Very often a high proportion
of the cost of an investigation is in
getting people, tools, material and
equipment to where the probes need to
be completed.
In some work environments a critical
element to the success of the
investigation is knowing where to park
the truck full of tools.

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Cost Envelope
There are all sorts of ways to play
with cost numbers, but one habit that
architects seem to be very good at is
making the boxes on bid forms too
small to fit very much of any numbers
in them at all.
Worse than that, often the way the
numbers are broken out into boxes
makes no sense at all and goes a
long way to scaring the probe
contractor away from placing a bid.
Everyone in the construction industry
knows, particularly on the supply
side, that rarely does anyone read
the document: they look at the $
number.
General conditions, mobilization,
demobilization, site logistics,
protection -- they should be broken
out from the unit cost of probes as
separate line items.
It can be amazing just how
much has to be completed,
and at what cost, in order to
collect a few sentences worth
of valuable information.
The cost envelope is an
overlay generally based on time,
labor and materials to be expended.

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Political Envelope
Project Politics: Though
not directly related to the doing of
probes, often there are
interrelationships of various levels
of misunderstanding and stress
involved within the investigative
team.

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RFP: Request for
Proposal
When you provide photographs with
an RFP take the in-shot -- say, the
area where you want the hole in the
ceiling, and then the out-shot -- step
way back and capture the entire
space envelope.
If your investigation is out on the
street, take photos of the street. Look
at the signs -- when can the
investigation team park here?
Are there any really difficult
conditions that will make reaching the
work a more than usual problem?
The header probes were on
the exterior 19th floor of a
high-security building and
there was no access for
anyone on the pre-bid
walkabout to get to see them
up closely. Nobody seemed
to know if they were terra
cotta or brownstone or cast
iron. The RFP said, make
holes and repair in kind.
Do not focus on how you think
someone should go about enabling
you to get the information, think in
terms of the result that you want.
What are you looking for?
Do not draw a bunch of 2’ x 2’ boxes
and then not explain what it is that
you need to know.

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De-Construction
Logic
With heritage construction there is
something to be said for being able
to ask the craftsperson what it is that
they think they are looking at, “Why
do you think they would have built
this like this?”
In doing probes there is
always the question, “How do
we get from here to there
with the least waste of time,
energy or resources?”
Simply said, start with the
end in mind.
The probe contractor should be able
to provide a flexibility to make
changes as the investigation
progresses, but to also be able to
keep in mind the steps needed to
close the project at the end.
A probe gig is a staged event with
beginning, middle and end.
Real-time flexibility of management
of the time and space envelopes
optimizes the ratio between
resources expended and value of the
information collected.

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Process
the vacuum cleaner
The paper we were handed
described the probes that were
intended. The descriptions, though, it
turned out once we started to make
the holes, left a whole lot to be
desired.
Turns out the paper was meant to
convince someone to allocate the
funding for the probes and thus the
thinking on the part of the person
who put the paper together never
went as far as to consider what the
person standing there with tools in
hand would need to know.
The process was not fully thought or
communicated through to the end.
Every single government
agency that we work with has
a different process.
Most of the time we have no
clue what that process is until
we are already in the thick of
engagement with the project.
For us it seems like the rules
are constantly changing to
make life more difficult.
Though you may know
what is going on, you need to keep
in mind that nobody else around
you may have any clue as to your
process.

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Insurance
A contractor who specializes in probe
work is not running a large capital
operation and may not be able to
provide the levels and types of
insurance that a General Contractor
is able to provide.
At the same time a GC may not have
the specialized knowledge,
experience or management focus
required for engagement in a team
based investigation.
A GC can provide labor to make
holes in a wall but maybe not a level
of knowledge that needs to be
applied to make informed and flexible
decisions in the field.
For two days of work we
were once asked for $17
million in General Liability
insurance. We told them to
go away.
Five weeks later they came
back and said OK to our
existing insurance coverage.
The probe contractor
needs to know before they
provide a work proposal what may be
expected for insurance requirements.
It does no good for any project for a
probe contractor to provide a
proposal and then find out that there
are insurance requirements that they
were not aware of and that they may
not be able to meet.
As well, organizations need to
understand that they may not be able
to get the insurance that their legal
team has outlined.
Rule: It never gets easier for anyone.

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Who is Hiring?
Situations vary from project to project
but the general industry tendency is
that the end-client, whomever is the
owner of the property, or represents
the owner, contracts directly with the
probe contractor.
The activity of the investigation is
then directed by the structural
engineer or architect in coordination
with the probe contractor who has
responsibility for means and
methods.
The insurance industry makes clear
distinction between the liabilities of
design work and those of physical
activity with labor, tools and
materials.
When the question comes
up, “Who are we working
for?” what is actually being
asked is, “Who writes the
check, who pays for this, and
to whom are the insurance
certificates addressed?”
Probe contracts are fulfilled
on credit. That is, credit
extended by the probe
contractor to the party that is
obligated to pay.
Will the probe contractor be
hired directly as a subcontractor on
your design team, or will they be
contracted to work for someone else?

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Notice to Proceed
(or Not)
Communications are always vital to
the success of a project, but one of
the most important pieces of
information to clearly communicate to
a probe contractor is that they have
been chosen for the work, that they
will be paid, and that someone
actually wants them to get started.
A phone call is not sufficient... there
needs to be a paper trail.
The next vital communication, at
least as a courtesy, is to let the probe
contractor know they have not been
chosen, so that they know they are
free to go about their business
elsewhere.
An RFP should be structured
in such a manner that the
probe contractor will
understand the process by
which they will be provided
with written documentation to
confirm that a contract
relationship exists.
What? You wanted us to start
yesterday?
But, we won’t be able to be there for
another week.
We sent in our bid three months ago.
This is the first we have heard back from
you!

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Optimal Approach The engineer in their RFP asked that
the contractor include in their
proposal to drill sixty 1/2" diameter
holes into the concrete foundation
wall.
The RFP was not clear as to why the
holes were needed.
When the crew went to the site with
the engineer they drilled three holes
and it was agreed by everyone on
the team that there was no more
information to be derived from the
remaining fifty-seven holes.
Regardless, the engineer was
flustered that the end-client would
think that money was being wasted
because work was not being done..
The engineer insisted that the
remaining holes be drilled, looked in
and then patched up. This was a
waste of resources.
Drilling stupid holes, the crew felt
used and disrespected for their
experience.
The optimal approach is
about how to get to the
needed information with the
least waste of anyone's
resources.
The optimal approach is
not about how to make better faster
holes in a wall.
It is not about counting how many
bricks are moved.
It is not about a 2’ x 2’ square
mapped on a drawing.
It is not about how many hours that
it took to do this task.
Sometimes the optimal approach is
not so much what you do on the site
as that you are awake and alert and
able to think on your feet.
HOW
WE
GET
HERE

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Closure
Closing up of probes, particularly
where heritage fabric is involved, can
be more time consuming and costly
than the resources expended to do
the probes and obtain the
information.
The RFP should specify at which
point in the investigation and closure
process the final end ‘period’ is
placed and all is done and
completed.
Generally the people who need and
want the information are long gone
from the scene when it comes to
clean-up and closure.
When poorly dealt with, the
poor closing of probes and
clean up of an investigation
session can leave a lasting
negative impression with the
end-client.
When the focus is on the
collection of information, very often
what is neglected is consideration of
how probes will be closed and
finished up.

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The End

Probes: Destructive Investigation

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