I assume the point of water infiltration has not been pinpointed
Could start by running a hose across the lowest row of shingles, slowly, from one end to the other. look for any water leaks on the interior. Repeat on the second row of shingles, then the third and so on until the leak is located. The fix will be dictated by the location of the leak
Well I'm close to knowing already where the leak is; I know it's coming in right where the valley meets the exterior wall --but your advice is great! I'll give that a try this weekend and see what I find...
I notice missing 3-tab shingles in two locations, a plumbing vent penetration whose boot has been either covered of replaced with a large amount of Vulkem or sealant. Note the EPDM used to manufacture the boots deteriorates in the presence of hydrocarbon based sealants. Flashing around the condenser and skylights as well as the woven valley would also be prime suspects for leaks.
True but I actually don't think I have any leaks other than the one right at the end of the valley. I already have access to the base of the central air unit, and all the vent pipes. There are no leaks there. I'm assuming my skylight doesn't leak but if it does, it must be a very small leak since I have no drywall damage in the bathroom it feeds. I'm probably going to be gutting that ceiling anyways so I'll find out for sure soon!
A truly hack fix can be affected by using adhesive backed ice/water shield tucked under a row of good shingles above the leak and adhered over the leak. The ice/water shield is not UV resistant and will break down over months, but I used this technique to stem leaks in areas of my roof giving me time to tear-off, re-flash and re-roof section by section.
Awesome tip! I just Google'd Ice and Water Shield and found some great information on some possible repair techniques. I think I'm going to first remove the bad shingles and determine what's going on underneath, then start my repairs from there... Thx again!!
For starters it's very difficult to maintain the watertight integrity of a valley with there is something like that evaporative cooler so close to its centerline, and extremely difficult - some roofers will tell you virtually impossible, on a long-term basis - to maintain it when you have a penetration like that skylight as close as you do, at a minimum it's going to require careful detailing with waterproof shingle underlayment on both sides of the valley and up the curb of the skylight.
Actually, it's a central air / furnace unit I have running there now. I had the swamp cooler removed a few years ago. Still, I have had expert roofers up there to deal with sealing around that unit, the old hole where the old cooler was mounted, and the skylight. They actually don't leak at all right now (but I DO understand that this is just a matter of time). Still, it's good to be reminded that these areas will need attention in the future (until the new roof is built). Thx for your thoughts!
