I need to waterproof behind a corner board that runs diagonally up a chimney shoulder. How do I do this? Should I not bother flashing but just replace the now-damaged existing cornerboard and caulk the joint? If I step flash it do I nail into the masonry?
Thanks,
Jon Fish
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Replies
it's very hard for me to figure out what you are describing...
if the board is pitched, and above the chimney shoulder (? what is that ? ).... the flashing goes behind the board and is let into the masonry and stepped in the brickwork...
but how is this a "corner board" ? is it at one of the corners of the house ?
if you could post a picture of it, I'm sure you'r get lots of advice.. some of it even worth listening to...
Mike Smith Rhode Island : Design / Build / Repair / Restore
Mike, I am guessing he has a Barge rafter or a fly rafter or whatever you want to call it just kissing past the outside of a chimney set in the gable end.Probably won't need to step flash it,just bend a slight z strip to cover the area in question and then counter flash into the brick work.
I think the "shoulder" is the part of the chimney where it narrows. I have siding butting into a "corner" board that runs up entire height of the chimney. It appears water is running down the chimney and getting behind the trim board that runs diagonally up the "shoulder". There is probably no flashing behind there. Does that make more sense?
sorry, no..
i've seen a lot of chimneys and a lot of attempts to flash them... my thinking. chimneys don't belong on the exterior wall..i've never seen a good solution.. the best attempt is usually a large overhang so the chimney almost becomes an interior chimney..
the trim board running vertically up the chimney is usually leaking just like yours..
running ice & water up the sheathing BEFORE the chimney gets built seems reasonable..
i've seen some flashed with counter flashing at every course.. which is fine as long as the mortar joints are maintained...
vertical masonry abutting wood siding is just a difficult situation..Mike Smith Rhode Island : Design / Build / Repair / Restore