Insulation Systems: Inspection and Maintenance

June 1, 2014

Insulation systems, like all
mechanical systems, require periodic
inspection and maintenance. While
inspection and maintenance are the
responsibility of the owner, the fact is
that many insulation systems are
frequently ignored. With time,
insulation systems can be damaged, and
if they are not repaired or replaced,
they can become ineffective. Insulation
contractors can play a key role in
facilitating regular inspection and
maintenance programs to prevent this

Failure to perform inspections and
implement a timely maintenance plan
carries a number of risks. On hot
systems, missing insulation results in
increased heat loss, which may translate
to significant economic losses over
time. For outdoor systems, damaged or
missing weather barriers can allow
rainwater entry, which can compromise
the effectiveness of the insulation
system. On cold systems, damaged vapor
retarders will lead to increased water
vapor intrusion, which can reduce
insulation effectiveness, increase rates
of corrosion, and increase the potential
for mold growth. If an inspection
reveals missing or damaged insulation,
repairs should be scheduled as soon as
possible. This is particularly true for
cold systems, where water vapor
intrusion can rapidly spread.

At a minimum, insulated areas should
be inspected annually. Inspection of the
external surface should include checking
for signs of cracking, distortion,
damage, or corrosion; evidence of hot
spots on high-temperature systems; and
condensation and ice buildup on low-temperature systems. When necessary,
external finish should be removed to
enable inspection of the insulation and
attachments. Infrared video cameras have
been found to be useful for inspection
and should be considered for use after
the start-up inspection and for ongoing
insulation maintenance.

When removal and replacement is
indicated, re-insulation should be
performed in the same manner as the
original installation unless the nature
of the damage indicates that the system
was improperly insulated or the
materials originally used are now
outdated. Damaged insulation should be
torn back to undamaged material. Care
should be taken in removal of existing
insulation to minimize damage. Temporary
protection for adjacent insulation may
be required to prevent damage while
repairs are underway.

The following “Risk Assessment
Discussion” and “Maintenance
Check List” have been designed by
the National Insulation Association
(NIA) along with the National Mechanical
Insulation Committee for mechanical
insulation applications as defined in
the National Institute of Building
Sciences’ (NIBS’) Mechanical
Insulation Design Guide (MIDG).

Assessment Discussion

There are risks associated with not
maintaining a mechanical insulation
system in a timely and effective manner.
Those risks and the severity of
potential consequences will vary
depending upon the use/service
temperature of the operating system on
which the insulation is installed, the
surrounding environment, ambient
conditions, the extent of any damage to
the insulation system, the insulation
system design, quality of the
installation, the timeline of correcting
any damage, and other occurrences that
may be unique to the area in question.

The following list depicts the type
of risk that could occur if you fail to
implement a timely and effective
mechanical insulation maintenance plan.
However, as previously mentioned, they
may not apply to all situations, and may
occur separately or simultaneously:

  1. Increase
    in energy costs
  2. Increase
    in greenhouse gas emissions
  3. Loss of
    process/production quality and increase
    in costs
  4. Occurrence of corrosion
    under insulation
  5. Development of condensation
    or ice, depending upon the service
  6. Development of mold or
  7. Decrease
    in personnel safety
  8. Decrease
    in personnel productivity
  9. Loss of
    time spent on other projects
  10. Decline
    in facility appearance
  11. Decrease
    in the life and operational efficiency
    of equipment in the area
  12. Increase
    in “life-cycle” cost
  13. Failure
    to obtain sustainability
  14. Failure
    to obtain return on investment

Each company and individual has their
own level of risk tolerance; however,
the risk of failing to establish a
timely and proper mechanical insulation
maintenance plan is real and should not
be overlooked or underestimated.

“Maintenance Check

Upon observing any of the following
conditions, a maintenance request/action
plan should be implemented to assess the
degree of damage, and the damaged area
of the insulation system should be
repaired or replaced to prevent further
damage and to avoid further risk. The
listing does not appear in order of
importance or priority. The Check List
is provided as a simple guide for
individuals evaluating the condition of
an installed mechanical insulation
system. It is not intended to be all
inclusive or to provide sufficient
information to act as a stand-alone
document that would allow anyone,
experienced or inexperienced, to
function as an inspector of mechanical
insulation systems.

Checking for all of the following
occurrences is a good start for a
maintenance plan:

  • Damage
    to or wearing of the outer
    jacketing/finish of the insulation
    system (damage could be caused by
    mechanical abuse, negligence, or
    weather; or it could simply occur over

  • Unsealed penetrations in the insulation
  • Missing

  • Insulation that has been removed and not
    yet replaced

  • Insulation supports that are failing or
    appear not to be working
  • Ice,
    mold, mildew on/in the insulation

  • Condensation

  • Discoloration of the insulation system,
    other than by dirt

  • “Fish mouthing” of the outer
    jacketing seams
  • Missing
    or loosening of insulation system
  • Sagging
    or pulling away of the insulation

  • “Hot spots” in the
    insulation system

  • Appearance of moisture on the insulation
  • Joints
    in the insulation that appear to be

  • Expansion or contraction joints that
    appear to be functioning

  • Insulation system being used in an
    environment or service that is different
    from the original design for the
    insulation system

With proper attention and
maintenance, insulation systems can save
a company considerable energy and money
over time, and improve process
efficiency and equipment life.
Mechanical engineers and insulation
contractors can play a key role in
facilitating regular inspection and
maintenance programs to achieve this