Flat Roof Leak Detection

Flat roofs are everywhere. Most commercial, institutional, and industrial roofs are flat roofs.  Thousands of millions of square feet of flat roof are installed each year.  Flat roofs are expensive to install ($4 to $6 per SF or more for a new roof) and replacement roofs can cost as much as $8 to $10 per square foot when disposal costs of the old roof are included.

Roofs are often ignored as part of the building maintenance plan.  The roof only gets attention when it makes itself known, and the only time that happens is when it leaks.  Forty-five percent (45%) of all new roofs develop serious problems within one year of installation.  The National Roofing Contractors Association estimates that the sources of the problems are due to:

  1. 50% - Poor workmanship
  2. 20% - Poor design
  3. 15% - Poor maintenance
  4. 10% - Material failures

Flat roofs are highly susceptible to leaks and water damage.  Once a leak begins, it will saturate the insulation beneath it, diminishing the R-value of the ceiling's insulation and adding unneeded heating and cooling costs to a building.  Luckily, IR is a very quick and easy way to locate flat roof leaks! 

Detecting the leak must be done at nighttime, typically a couple hours after the sun goes down.  There also must be at least two or three days of no rain before the test can be completed.  The pictures below illustrate how the IR camera detects moisture in a built-up-roof system (BURs).

Throughout the day the sun's heat will warm the surface of the roof.  The areas which contain water beneath the surface will warm up much slower than the rest of the roof area.  The reason for this is because water has a higher thermal capacity than the surrounding insulation materials, and absorbs heat at a much slower rate.

 

 

heat released from roof

At nighttime, after the sun goes down and the roof starts to cool off, the areas where moisture is trapped beneath will still be releasing the heat that was stored all day from the sun and can then be easily visible as "hot spots" when compared to the rest of the dry roof areas.

 

 

dry/wet insulation comparisonOnce the roof leaks have been detected, the area is marked off with spray paint so that a roofing contractor can easily find and repair ONLY the areas that are damaged.  This can ultimately save the building owner THOUSANDS of dollars in unneeded roof replacement costs!

 

IR roof pictureThe picture to the left shows an example of what the IR camera sees at nighttime.  The difference between hot and cold, or wet and dry in this case, is very clear.  There is no disputing this visual evidence. 

 

 

The losses from premature roof failure run into the billions of dollars every year.  These dollars are lost, and are not available to support or extend business operations.  The primary costs associated with roof failures include the following:

  • Excessive energy consumption due to reduced insulating value of wet insulation
  • Losses due to water leakage into the building, resulting in problems ranging from minor nuisances to catastrophic and life-threatening situations. Leaking roofs can cause total building outages when water invades electrical switch gear and critical production equipment.
  • Damage to the roof membrane and the structural roof components caused by trapped moisture in the roof assembly.  There are numerous accounts of people being seriously injured or killed when they fall through a flat roof because the roof lost structural integrity due to water damage.
  • Loss of salvage value of the roof insulation at the time of membrane replacement because it has become wet.  The cost of disposing and replacing insulation can cost $3 to $5 per square foot.

The average life of a new roof in the US is seven years.  Because some roofs last over 30 years, it is clear that a lot of money is being spent that could be put to better use.  All that’s needed is regular maintanence!  Contact us to learn more about regular IR inspections as part of your routine maintanence program and how much you could potentially save!