jsduke
Bronze Member
Hey all, this is going to be a tad involved but please bear with me.
This concerns a leaking chimney area at my abode. The chimney is a vinyl-clad, wood-framed, OSB sheathed and steel-lined structure. Inside the steel lining an 8 inch stainless flue pipe is suspended and a 6 inch stainless pipe is suspended inside the 8 inch. The 8 inch pipe served as the flue for the metal fireplace which was original to the house when we bought it. Several years after moving in we had a cast iron wood stove installed in front of the fireplace and the 6 inch pipe serves as its flue. The house was built in the late 80's and we've been here for 9 years.
A few years back, in the late winter or early spring, we started getting water accumulating on the top of the old fireplace's firebox during a rain/snow melt. It was pooling and then overflowing into the bottom of the firebox and eventually onto the hearth under the woodstove. In the spring heavy rains would create the same scenario but only after several hours or so. We could hear the water dropping loudly onto the top of the firebox.
A tarp placed over the top of the chimney stopped the problem.
Of course a woodstove isn't useful if its flue is covered. In the summer the flat top of the chimney was noticeably sagging and some small gaps or cracks were visible. These were caulked. Problem temporarily solved. Rains didn't appear to cause anymore leaks.
The following winter more snow accumulations followed by melting rains and the leaking resumed. In addition the drywall above the fireplace started getting wet from the inside (some minor mold growth visible on the outside as well). The chimney structure contacts the house at 2 separate roof levels, 1 higher and 1 lower. These contact areas are directly downslope from the respective peaks. In other words rain will run down the slopes of each roof and contact the face of the chimney. It will then divert around the chimney to gutters. The lower roof contact point was identified as the culprit in the drywall problem and a tar like caulk abated the leak, for a time.
Last summer/fall we gave up and hired a pro (chimney specialist) to resolve things. He built a rounded galvanized steel 'roof' over the top of the chimney with an access for the pipe and cap. He also fabricated a steel 'collar' around the pipe/cap to help protect that area. He redid the caulking at the lower roof juncture and caulked all around the top/pipe/cap area. He also shot caulk up in the upper roof juncture as well. We gave it a wait and see.
The drywall problem did not reappear. The leaking on the firebox resumed immediately. The pro was called.
He removed some vinyl siding on the chimney face at the upper and lower juncture. The OSB at the upper area showed rot and a hole. OSB above the hole was removed and as a hose was used to simulate rain the pro observed water building against the OSB and pouring through the hole and into the chimney between the OSB and the steel liner. The water was apparently getting under the asphalt roof shingles and reaching the OSB.
To correct the problem flashing was installed as well as new shingles. The rotted OSB was replaced as well. The Lower juncture was treated the same way.
He finished on friday. It rained heavily, but briefly soon after and all seemed good. Today (sat.) a lighter yet far more sustained rain fell. After a number of hours... Drip Drip Drip!
It's water torture! /forums/images/graemlins/mad.gif
Before I drag this guy back out I thought I'd run it past the TBN brethren for ideas.
The only thing I thought of (and I spoke to the pro about some time back) was a possibility of moisture condensing on the underside of the rounded galvanized 'roof', then dripping and pooling on the original chimney top and eventually finding its way into the core and onto the firebox. The reason I thought of this is because there seems to be a significant lag between the onset of precip. and the onset of the drip. Must be pooling somewhere. Funny thing is we tarped his steel 'roof' for a time(a few months back) and it didn't stop the drip, although there was a smallish hole in the tarp over the 'roof' area.
I need your help and expertise. I gotta get this solved. /forums/images/graemlins/confused.gif
Thanks.
duke.
This concerns a leaking chimney area at my abode. The chimney is a vinyl-clad, wood-framed, OSB sheathed and steel-lined structure. Inside the steel lining an 8 inch stainless flue pipe is suspended and a 6 inch stainless pipe is suspended inside the 8 inch. The 8 inch pipe served as the flue for the metal fireplace which was original to the house when we bought it. Several years after moving in we had a cast iron wood stove installed in front of the fireplace and the 6 inch pipe serves as its flue. The house was built in the late 80's and we've been here for 9 years.
A few years back, in the late winter or early spring, we started getting water accumulating on the top of the old fireplace's firebox during a rain/snow melt. It was pooling and then overflowing into the bottom of the firebox and eventually onto the hearth under the woodstove. In the spring heavy rains would create the same scenario but only after several hours or so. We could hear the water dropping loudly onto the top of the firebox.
A tarp placed over the top of the chimney stopped the problem.
Of course a woodstove isn't useful if its flue is covered. In the summer the flat top of the chimney was noticeably sagging and some small gaps or cracks were visible. These were caulked. Problem temporarily solved. Rains didn't appear to cause anymore leaks.
The following winter more snow accumulations followed by melting rains and the leaking resumed. In addition the drywall above the fireplace started getting wet from the inside (some minor mold growth visible on the outside as well). The chimney structure contacts the house at 2 separate roof levels, 1 higher and 1 lower. These contact areas are directly downslope from the respective peaks. In other words rain will run down the slopes of each roof and contact the face of the chimney. It will then divert around the chimney to gutters. The lower roof contact point was identified as the culprit in the drywall problem and a tar like caulk abated the leak, for a time.
Last summer/fall we gave up and hired a pro (chimney specialist) to resolve things. He built a rounded galvanized steel 'roof' over the top of the chimney with an access for the pipe and cap. He also fabricated a steel 'collar' around the pipe/cap to help protect that area. He redid the caulking at the lower roof juncture and caulked all around the top/pipe/cap area. He also shot caulk up in the upper roof juncture as well. We gave it a wait and see.
The drywall problem did not reappear. The leaking on the firebox resumed immediately. The pro was called.
He removed some vinyl siding on the chimney face at the upper and lower juncture. The OSB at the upper area showed rot and a hole. OSB above the hole was removed and as a hose was used to simulate rain the pro observed water building against the OSB and pouring through the hole and into the chimney between the OSB and the steel liner. The water was apparently getting under the asphalt roof shingles and reaching the OSB.
To correct the problem flashing was installed as well as new shingles. The rotted OSB was replaced as well. The Lower juncture was treated the same way.
He finished on friday. It rained heavily, but briefly soon after and all seemed good. Today (sat.) a lighter yet far more sustained rain fell. After a number of hours... Drip Drip Drip!
It's water torture! /forums/images/graemlins/mad.gif
Before I drag this guy back out I thought I'd run it past the TBN brethren for ideas.
The only thing I thought of (and I spoke to the pro about some time back) was a possibility of moisture condensing on the underside of the rounded galvanized 'roof', then dripping and pooling on the original chimney top and eventually finding its way into the core and onto the firebox. The reason I thought of this is because there seems to be a significant lag between the onset of precip. and the onset of the drip. Must be pooling somewhere. Funny thing is we tarped his steel 'roof' for a time(a few months back) and it didn't stop the drip, although there was a smallish hole in the tarp over the 'roof' area.
I need your help and expertise. I gotta get this solved. /forums/images/graemlins/confused.gif
Thanks.
duke.
