Finding flat roof leaks
Many buildings, both commercial and residential, have flat or low sloped roofs. The roof coverings can be of many types.
- Tar and gravel
- Consisting of a concrete or wood roof deck over which layers of heavy felt roofing paper are built up and sealed using hot tar. A top layer of gravel is usually added to act as a sunscreen.
- "Torch down"
- A composition roofing material that comes in rolls and is applied in the long, overlapping strips. The backside of the material has an adhesive coating that is heated with a large propane torch to make it tacky so that it bonds to the surface it is being applied to as well as the adjacent strips of roofing.
- Membrane or diaphragm roof covering.
- This type of roof covering consists of a single layer of EPDM material that is "heat welded" together at the seams. This type of roof may or may not have ballast in the form of gravel or rocks added to the top to prevent lifting or "ballooning" due to wind pressure passing over the roof.
Finding leaks.
Finding leaks in a flat roof system can be difficult.
typically, physical inspection is performed to detect any obvious areas of concern such as unsealed roof penetrations by plumbing or other mechanical equipment, missing or damaged parapet flashings and physical damage or deterioration of the roof covering itself.
Usually, a leak will manifest itself as moisture intrusion on the interior finish surfaces. Unfortunately, there is often not a direct relationship between the location of the leak and where it shows up on the inside of the building. Water will obey the laws of gravity as well as take the path of least resistance and may travel many feet along structural components before dripping off onto the ceiling itself and alerting the occupant to a problem.
Barring the presence of any physically identifiable defects in the roof covering itself, finding the actual source of the leak can be quite difficult. The usual method of repair is to have the roofer reseal every possible leak source in the vicinity of the interior leak. Sometimes this is effective, often it's not. If the exact location of the leak cannot be identified, many roofers would just suggest a tear off and recover or just a recover of the entire roof. While this “shotgun” method may solve the problem, it's expensive, not very efficient and adds a lot of perfectly good roofing material to the landfill. Not very “Green”!
Thermal Infrared Scanning to the Rescue!
Due to a property called "thermal mass" saturated roof decks and insulation will absorb and hold more heat from the sun during the day than the dry areas of the roof. This heat can be detected as infrared radiation and quickly spotted by a specialized, high tech Thermal Imager like the FLIR B-CAM used by The Magic Leak Finders.
Roof surface during the daylight hours absorbs heat. The wet areas absorb more and hold it longer due to increased thermal mass of the wet materials.
At night, during a time of maximum heat difference between the cold sky and the warm roof deck, the wet areas will show up in the thermal imager as a “thermal hot-spot”.
The light yellow areas of this picture are the saturated areas of this roof system.
As the building owner, what does this mean for you?
By using a company like Thermal-Diagnostics & Magic Leak Finders to quickly identify the source of the leak, you could potentially save a significant amount of money by avoiding a complete roof replacement or recover when not necessary and only repair the areas that need it.
The cost difference can be significant. Compare the cost of a full roof replacement or recover at $3 to $5 per square foot to the cost of a Thermal Roof Scan and repair of the leaking areas only.
In the Los Angeles, Ventura & Orange County areas, contact
9 comments:
Its the first time I have heard about the flat roof leaks. But one thing is sure that with the flat roof you have always the ease to go for the roof coatings. Its easy to use any kind of coat application with the flat roof.
RV Roof Repair
This thermal infrared sensor for roof leaks detects leaks and their sources with a very high success rate. It will save a lot of money by not replacing roof tiles that are still ok. By the way, I have seen numerous Nassau County roofing companies that employ this kind of method to save construction time for the builders and money for the house owners. The investment is well worth it rather than replacing a part, a half, or your whole roof.
The methods being used today by the roofers in New York are evolving for the good of the roofing industry.
When looking at your thermographic photo, is the yellow, orange and red colors wet insulation at different temperatures?
Infrascan - Are you just trolling?
From your username, one might assume that you have some familiarity with infrared use.
The software in the camera simply displays a surface temperature difference as a color difference for a better visual interpretation by the operator. The reason for the temperature difference requires further invasive testing per ASTM C-1153 standard. It might be saturated insulation or some other reason.
I used to perform infrared surveys to flat roofs 20 years ago with a camera called the Hughes Probeye which was cooled by argon gas. This camera only showed images in greyscale, not like today's new cameras.
Roof Repair
Wow, that's pretty old school. I bet they were very expensive as well. A decent camera for home inspection work runs about $4000 to $6000 these days and is probably 10x as sensitive and has a much higher resolution.
Would thermal-diagnostics detect a leak in a wall? We've tried taking out the siding and reinstalling the flashing and caulking and still almost every rain storm causes water to come in.
Julie...
Yes, thermography and infrared cameras can detect a temperature difference anywhere there is one.
In the hands of an experienced operator, a thermal camera along with a good knowledge of building science can find many leaks.
The camera is just a tool. It takes an experienced user to interpret the data the camera is providing and apply it to the current situation.
In my case, I bring to bear the thermography training and 30 years in the construction trades as well as using a moisture meter to verify that what I am seeing with the camera is actually a moisture caused anomaly and not something else.
NOTE; HOME DEPOT ROOF SEALEANT/COATING ACTUALLY HAS IN FINE PRINT, "DOES NOT SEAL LEAKS". WHAT THE HECK AM I COATING THE ROOF FOR,,READ THE FINE PRINT..
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