Perhaps your green roof looks like the thriving meadow land pasture you have always dreamed of, yet your ceiling is discoloring and there is water damage in the attic. Finding a leak is difficult enough on a normal roof, but the layers of substrate, rubber membranes, and plant roots make it even harder to find water penetration on a green roof. Try more than one of these detection techniques to keep your roof repair costs under control by limiting the water damage with prompt sealing.
With a basic green roof design or a DIY project, your main diagnostic tool for finding leaks involves flood testing. The entire roof is soaked until at least two inches of water is standing over the entire structure, and then the roof repair specialists start examining for signs of fresh moisture from the inside of the house. The standing water can start leaks and damage the roof, but it's one of the only tests available unless your roof was equipped with leak detection equipment during the building process.
Trial and Error
Of course, flood testing only works on a flat green roof, not a sloped one. If your roof is too pitched to use this test, or you don't want the chance of further damage, consider hiring a repair team to make repairs along the areas most likely to leak on a green roof. These spots include
- Where chimneys, vents, and other protrusions poke through the roof
- Seams where two sheets of roofing membrane meet
- Edges along roof side walls, parapets, and other areas where horizontal and vertical planes join
You'll end up spending quite a bit on preemptive repairs on all these areas, but a little sealing and flashing replacement could suddenly put a stop to your leak problem. If you don't see any further signs of water after the trial and error work, you've most likely fixed the problem in the process.
The very best way to find leaks in a green roof unfortunately involves equipment that must be inserted during the original installation. However, if the leak is bad enough that you must refinish the layers of membrane and plant substrate anyways, it's the perfect time for inserting the sensors for an electric field vector mapping (EFVM) system. An entire layer of conductive material is laid out under the rest of the roofing materials so a repair technician can pinpoint the exact location of moisture thanks to the conductive nature of water.
EFVM is fairly inexpensive and easy to install, especially with liquid paint-on membranes, but it still takes a technician a few hours of inspection to find all the leaks. Automatic leak alarms are also available to send warnings to you as soon as the roof's conductivity increases due to moisture. Unfortunately, that kind of equipment is much harder to install, even on a brand new roof, and it comes with a high price tag.
When trial and error repairs and flood testing fail to work, it's time to turn to destructive examination methods. The roof repair team can cut up sample squares from suspect areas of the entire roofing material sandwich, from the first waterproof membrane to the top layer of plants. This lets them check for moisture in each layer to look for penetration. You'll still need major patching repairs if they find the leak this way, so it's usually best to just invest in a replacement roof at that point and let the contractors discover the cause of the failure during the demolition stage.
Since every method but EVPM has a chance to damage your green roof even further, it's best to invest in this technology when first switching to an eco-friendly design. If you opted not to buy it in the first place, ask your roof repair contractors about installing one now as they work to stop your leaks and repair the water damage.
For more information about roofing repairs and installation options, visit sites like http://www.palmerroofing.net.