There is an old saying: Measure twice, cut once. We all have “check” or “to do” lists to help us remember what needs to be done. Many of us rely on our memory, but it is usually a good idea to put the lists in writing so that when we are in a hurry we do not forget anything. The checklists below were developed primarily for below-ambient piping systems but would apply to any insulation application. The items listed are in general terms, so there may be additional items to add to tailor the list to your needs based on past experience.

There are three main functions that take place during an insulation installation: (1) job layout or estimation, (2) actual installation, and (3) quality inspection of the job once it is complete. The checklists below have been broken out for these three functions. The responsible party for each function also is noted.

Job Layout/Estimation (Responsible Party: Estimator)

• Review all system operating temperatures to be sure they are consistent with insulation use temperatures. Consider any temperature cycling and/or yearly maintenance that may affect system temperatures.
• Determine the desired design conditions and the performance requirements of the insulation system. For outdoor systems, be sure to take into account the site location, likely weather conditions, and weather extremes when formulating the proper design conditions. Based on this information, determine the appropriate insulation
  thickness to be used.
• Based on the site conditions and expected service conditions (UV exposure, exposure to chemicals, mechanical abuse, etc.), select the proper jacketing/protective covering/coating for the insulation. Note that many sites will have “standard practices” or internal specifications that will call out insulation system finish requirements.
• Consider the following when deciding on the insulation configuration/style.

1. 1. • Method of installation – i.e., mechanical attachment, adhesive, clam-shell, slide-on or
        slit, etc.
      • Trade-off between labor and cost of materials. Some insulation systems cost more out of the box but install faster than cheaper systems. This saves labor and time during installation.
      • Trade-off between labor and insulation system performance: Factory-fabricated fittings may cost more in materials but save labor and improve uniformity and performance.
      • Trade-off between up-front material cost and maintenance costs down the road: Jacketed systems may cost more than those with a mastic finish but usually require less maintenance during the life of the insulation system.
      • Configuration and type of equipment to be insulated. What is the geometry? Take into account the fittings, valves, pumps, etc. How will these be insulated?

• Review the layout of the system or item to be insulated to be sure there is sufficient room for the insulation thickness specified without compressing the insulation or having the insulation come in direct contact with the insulation on other pipes or pieces of equipment. If not, can this be corrected? Check and see if there are protrusions along the system. Are they long enough to accommodate the recommended amount of insulation? If not, can they be extended or removed?
• Lay out the job in a manner to eliminate seams or minimize insulation joints as much as possible. If multiple layers of insulation are required due to thickness or other performance requirements, the insulation joints of successive layers should be offset from the insulation joints of the previous layer.
• When deciding on how to achieve the desired insulation thickness, consider practical handling of the insulation during installation (including the bending radius of the material) as well as the ability to achieve full joint closure. In addition, consult the insulation distributor or fabricator to verify the availability of different insulation sizes and configurations in order to select the most cost-effective way to achieve the desired thickness.
• Consider the required time frame for completing the job. If the time frame is short, as is typical for maintenance during a plant shutdown, you may want to consider using insulation materials that are quicker and easier to install (e.g., self-seal or factory-fabricated products) because of the time saved, even though the initial cost of these materials may be higher.
• Consider the availability of materials to be sure they can be delivered to the job in time.
• Consider the availability of labor and the skill of the labor pool, as this may make a difference in the choice of materials.
• Consider how important aesthetics are for the job.

Installation                                         (Responsible Party: Foreman)

• Review work orders/specifications for areas to be insulated and materials (thicknesses) required. Lay out a plan/schedule for areas to insulate first, coordinating with other trades that may be working in the area. Include your safety training and any special safety equipment that may be needed for the job.
• Be sure all materials (insulation, accessories/adhesives, tapes, jacketing, fittings, etc.?and tools) are on site or are scheduled to be delivered at the appropriate time. Be sure all materials are stored in a clean, dry room.
• Check materials against what was specified (i.e., proper sizes and thicknesses). Organize insulation according to size and thickness.
• Know job site conditions, including where other trades are working, what the weather will be over the period of the job, etc. Understand access to the working area. Because of potentially damaging environmental conditions, insulation used on outdoor applications nearly always requires protection (coating, jacketing, or cladding) from mechanical abuse and UV resistance. Remember, it is also important to protect the system from moisture intrusion during the installation process. Good practice dictates that no more insulation be applied in a day than can be properly sealed and protected from weather before leaving the site at the end of the shift.
• Check equipment/tools (lifts, etc.) to be sure everything is in place for what needs to be done.
• Check manpower and review the experience of workers. Develop a manpower allocation plan accordingly.
• Review the insulation manufacturer’s recommended installation procedures. If there are any questions, contact the manufacturer for recommendations.
• Check to be sure the piping system or equipment is turned off and at ambient conditions. Make sure it is clean and free of dirt or moisture.
• For most applications, it is recommended to apply the fittings first (which may be available for purchase pre-fabricated by a fabricator or the manufacturer, or can be pre-fabricated at an off-site location). After the fittings are installed, application can begin on the straight runs. The straight length material is usually easier to install than fitting insulation, so the straight run work will progress more quickly. Protrusions to the insulation system must be properly insulated and sealed. For below-ambient systems, protrusions should be insulated a distance of four times the insulation system thickness when possible. Protrusion on above-ambient systems should be insulated a distance of two times the insulation system thickness. For complex applications, contact the manufacturer for recommendations.
• Inspect workmanship as the materials are being installed. Notify appropriate personnel if problems arise.
• At the end of each day, be sure all materials are put away in a clean, dry area and that the installed portion of the job has been appropriately sealed/closed in such a way to prevent any damage from other trades or from the weather. Make sure all scrap insulation material resulting from field fabrication is either (1) put back in appropriate boxes to maintain size identification, or (2) appropriately disposed of.
• On cold applications, make sure that all seams are glued and sealed. Install vapor stops when needed (for details, contact the insulation manufacturer).
• When the job is finished, make a final inspection.

Quality Inspection
(Responsible Party: Engineer or Job Inspector)

• Obtain a list of all areas that were specified to be insulated (including material type and thickness). Obtain a data sheet and appropriate installation instructions from the manufacturer for each material.
• Conduct a preliminary inspection of the entire job. Make a list of any obvious issues that may need to be replaced, repaired, or corrected. Be sure all areas that were called out for insulation have been insulated. Also check for the overall neatness of the job.
• Check that installed materials comply with those specified (material type and size). Material type and size (ID and thickness) generally can be found on the product box or on the insulation itself.
• Ensure that all seams (longitudinal, butt joints, and terminations) have been sealed properly per manufacturer recommendations. Check all fittings, valves, etc. to be sure the insulation is sealed properly at any termination points.
• When checking materials and insulation systems, be sure there are no tears, cuts, or damage that would cause performance issues. If any are found, the damage must be repaired or the section of insulation completely replaced. Also, make sure that none of the insulation is wet and there is no moisture between the insulation and the substrate.
• On straight runs, make sure that seams are facing down to reduce weight/pressure on the seam.
• Inspect the insulation finish (jacketing, coating, or mastic) for damage and defects. For outdoor applications, it is generally recommended that all insulation materials be protected from the elements and mechanical abuse by jacketing or coatings, and that all jacketing laps should be positioned to shed water.
• On pipe and supported equipment, review all hanger and support areas to be sure they were handled according to manufacturer recommendations. The insulation should not be compressed, as the thickness of the insulation should not be compromised. Also, check all protrusions to ensure that they are properly insulated and sealed.
• If the system has been turned on, look for any signs of condensation or ice formation.

By using these checklists, and adjusting them for personal use by adding or modifying steps based on your experience, the job should meet the end user’s expectations and come in either at or below budget. “Measure twice, cut once” pays off more times than not in the long run. Taking short-cuts, particularly on an application involving below-ambient operating temperatures, is a bad bet.