I have not vompleted many flat roof surveys for water contamination and need a little advice. I have surveyed my plants roof and found water under a newly installed section of roof. The replacement roof is supose to be composed of fiber board and styrofoam. The only problem I see in my survey is that the water's thermal signature appears as a lake with all fingers intact. I would have thought that if there were any styrofoam I would be seeing thermal signatures of the butt cracks between the styrofoam and not the entire surface area of the roof that is covered by water. I have thought about this and believe that the styrofoam has been left out of the roof installation. Can anyone offer their expertise on styrofoam signatures thermally speaking and what I should be seeing? Pre Thanks for any hilp or advice you might offer. My mail is jbryant@kcp.com for I have had no luck post an image if one would help in your assistance.

Can you provide a complete description of roof construction-membrane, insulation, deck. Also-is the insulation expanded or extruded polystyrene. Expanded is also known as bead board. Styrofoam is extruded. Their moisture absorption qualities are quite different. It is unclear how you discovered the presence of moisture and where in the roof.

Had a leak through a crack in the roof in a department below roof (roof is concrete) , went back to roof for repair @ leak point and found new roof had been installed over leak. Didn't want to breech new roof so went and got camera for survey. Waited for substantial rain event, waited couple of days of sun, then clear night with less than 8 mph wind. Surveyed and found a large puddle of water under roof. Trying to find what roof is constructed of and will post when I find this information. Didn't think I would need so much information or would not have posted without it. I will repost with information on roof construction when I retrieve information. Thanks for your response!

JB,
If you can, post an image, even jpeg image format would say alot.
Regards,

quote:

I have had no luck post an image if one would help in your assistance.

Just below the lower-left-hand corner of the box where you type your message are the words "Add Attachment". Click on those words to add an attachment.

Roof construction is fiber reinforced pitch, fiber mesh, expanded polystyrene, covered by compressed fiberboard (Shredded wood fibers), and covered with granulated rolled fiber reinforced roofing.

Is the large purple area composed of roofing materials that are dissimilar to the surrounding orange areas? This almost looks like a large patch. You can clearly see the edges of the board stock in the foreground. It would help to provide a photograph of this area. That might help to identify the reasons for the irregular warm areas in the center. The wood fiber insulation will image very clearly when wet and should provide sharp thermal contrasts and may also show clearly delineated insulation boards. Your image does not contain that type of pattern. From your roof description, it sounds like you have new roofing imposed over original roofing. Otherwise, it us unclear why you would find a pitch membrane on the concrete, unless this is supposed to function as a vapor barrier.

The large purple area is dry roofing that gave up its thermal fairly quickly after sundown along with the remaining purple areas in the jpeg of the thermal. I believe that would indicate this portion of the roof is dry and uncontaminated.
The apparent long evenly spaced gap that the dual cones sit on is a pitch (tar) dam (horizontally across and vertically down toward the bottom of the jpeg) that was installed to seal the first section of new roofed area while waiting on the second stage to begin. It (the dam) gives up its thermal heat at about the same rate as the wet roofing. I was not allowed the time to stay and determine when and if they (the wet roofing and pitch dam) give up their thermal energy at the same time. The area between the two sets of dual cones is in question with regards to wet roofing. I assume that I am unable to register the thermal energy at the expanded polystyrene joints because it is being overwhelmed by the section of wet fiberboard roofing. Either that or the fiber board is soaking up the major portion of water entering the roof and not enough is leaching from the fiberboard to revealed energy stored between the joints of the polystyrene under the fiber board. There is some thought that the roof is short the polystyrene section and I am attempting to confirm or deny this avenue of thought. Thanks again for your response, and I hope I have offered a satisfactory explanation to your question.

Your discussion of the image sounds reasonable. A night seal can look exactly as does the dam in the image. This is because the area has greater mass and therefore greater heat storage capacity. If you are correct, that suggests a lot of wet insulation. Infrared images of roof moisture can often be ambiguous and should be verified. This can be done by using alternative instrument such as nuclear or capacitance gauges. However, even with these non-destructive test, some core samples should be taken to provide absolute verification, an idea of the level of moisture concentration, the location of the moisture and the construction methods used. In reviewing the image, I don't think you are seeing insulation joints. It looks more likely that you see the laps between the rolls of modified roofing. The somewhat broad elevated temps in the purple section that run perpendicular to the side laps are likely to be end laps. Again, these show elevated temperatures to the increased mass at these areas.