Ramble On

Monday, February 15, 2010

Chimney Chore

Weather and work deadlines kept us away from the Hawksbill Cabin for a longer interval than usual, and Mary and I needed to get out there to check in and see how things had fared during the snowpocalypse. Mary had made arrangements for the driveway to be plowed – twice, and she’d had our roofer Alan come out and shovel the snow off of the roof after the first big snow this month. Between the big December and January snows Alan had come up to install ice breakers and to upgrade the flashing at the base of the chimney, so this visit was also the first time we’d be able to check out his work on this small project.

The back of the house is partially below grade, so the above ground portion of that wall is between six and seven feet high. The snow that I shoveled off the roof in December lay back there in the shade, forming what ski resorts would call a respectable base of between two and three feet. In these approach photos, you can see that with the additional snow and from Alan’s shoveling, the snow was as deep as five feet behind the house, nearly blocking the clerestory windows.

We’ve had leaking on the chimney wall during heavy summer rains and also after the December snow began to melt. So my goal was to go up, shovel some snow from the roof, and then clear the chimney cap – where there was about two feet of snow remaining. I worked on this for about an hour – a wet and icy standing seam metal roof is slippery, so be warned, sports fans – and finally had the area cleared well enough to take a look at the new flashing job.

This is a technical solution to our leak problem, and it is often used for stone chimneys. The uneven surface doesn’t allow for a standard flashing installation to be effective, so you cut into the stone, inserting the edge of the flashing inside of the chimney. There is a mechanical attachment of the flashing to the base of the chimney, and then the overlap extends to the surface of the roof.

We talked to a couple of architect friends about the problem, including a couple of historic preservation specialists, before we settled on this approach. Fortunately, Alan was familiar with the method and was able to execute it for us. While there was no trace of the old leaking inside the house this time, I cleared the chimney cap off for good measure. Seems to be working so far.

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