I have a metal double-wall flue that runs from my fireplace through the roof. It exits through a "fake" chimney ... i.e., the chimney looks like it is made of stone. As I understand the construction, it is essentially a box built from wood framing and plywood, then some sort of coating was applied, then artificial/cast stones were applied and grouted. I saw some of the construction process and I'm certain that flashing was applied where the chimney meets the architectural shingle roof.
Immediately after construction, there was a slight leak noted in the attic around the framing of the chinmey where it joins the roof. Someone did the usual "apply sealant where it looks like it might be leaking" routine, and supposedly, it was fixed. A little later, it was obvious that it was still leaking - the builder theorized that the artificial stone might be imperfectly grouted and water might be leaking behind the "stone" and running down. He had a clear sealer applied to the entire "stone" surface, and this seemed to help. It's really difficult to tell about leaks - seemed to leak with some rains and not with others - probably has something to do with which way the wind is blowing, etc.
Anyhow, we're a couple of years out from the sealant application and just had some really heavy rains. Thought it would be a good time to check the attic and sure enough, it appeared to be leaking worse than ever! I'm now got about 5 strategically placed plastic buckets up there! The leaks are slow, but definitely there - it's hard to pinpoint since water can run along framing and drip several feet from its origin. They definitely emanate from the area where the chimney joins the roof and I think it leaks on more than one side - up inside the "box" it is dry as a bone. We have very thick stabilized cellulose insulation, so I think it has absorbed most of the water, so no ceiling damage ... so far.
Obviously, I want this definitively fixed! Any new ideas? I had a roof repaired at another house and the roofer grooved the brick with a saw and then caulked and inserted the top of the flashing into the groove. Looked to me like it would be near-impossible to leak. Wondered if this might be applicable to the chimney? Perhaps use a concrete-cutting blade and groove all the way around down to the wood base and caulk and flash? Any "miracle" sealants out there that could be applied to the artificial stone and still leave it looking like stone?
Regards,
John
Immediately after construction, there was a slight leak noted in the attic around the framing of the chinmey where it joins the roof. Someone did the usual "apply sealant where it looks like it might be leaking" routine, and supposedly, it was fixed. A little later, it was obvious that it was still leaking - the builder theorized that the artificial stone might be imperfectly grouted and water might be leaking behind the "stone" and running down. He had a clear sealer applied to the entire "stone" surface, and this seemed to help. It's really difficult to tell about leaks - seemed to leak with some rains and not with others - probably has something to do with which way the wind is blowing, etc.
Anyhow, we're a couple of years out from the sealant application and just had some really heavy rains. Thought it would be a good time to check the attic and sure enough, it appeared to be leaking worse than ever! I'm now got about 5 strategically placed plastic buckets up there! The leaks are slow, but definitely there - it's hard to pinpoint since water can run along framing and drip several feet from its origin. They definitely emanate from the area where the chimney joins the roof and I think it leaks on more than one side - up inside the "box" it is dry as a bone. We have very thick stabilized cellulose insulation, so I think it has absorbed most of the water, so no ceiling damage ... so far.
Obviously, I want this definitively fixed! Any new ideas? I had a roof repaired at another house and the roofer grooved the brick with a saw and then caulked and inserted the top of the flashing into the groove. Looked to me like it would be near-impossible to leak. Wondered if this might be applicable to the chimney? Perhaps use a concrete-cutting blade and groove all the way around down to the wood base and caulk and flash? Any "miracle" sealants out there that could be applied to the artificial stone and still leave it looking like stone?
Regards,
John