Hi All,
Think I know the answer but I’ll ask anyway.
Two 8″ clay liners in standard concrete chimney block. Flashing is on, finally getting around to the counterflashing and stucco.
Can I cut (grind) my recessed slots into block itself instead of the mortar joints? Think it would make for a neater looking job if feasible.
The outer portion of the block is about 1.25″ thick, figured I grind my slot about .5″ deep. Can post a pic of a chimney block, figure it varies by region.
TIA, Todd
Edited 4/22/2009 10:26 am ET by todd
Replies
I'd go about an inch deep - otherwise, carry on.
http://www.quittintime.com/ View Image
Grant, I hopefully attached a pic of a similar block. It's kind of "webbed" so I'll be pretty much cutting through the outer layer if I grind that deep. Or maybe your block look like that and you are saying it's okay? Hard to believe...Todd
Todd, I've done similar and it works if you don't go as deep into the block. You are stucco-ing right? That'll add some burying depth right there. I cut in 1/2'', hemmed the metal, packed it in and then stucco'd down to it. The stucco finished out probably 1/2'' easy.
The caution is that any water will be repelled over the step flashing, but if some enters at the bottom of the stucco, could freeze and crumble it at the flashing. I caulked with urethane at the flashing/block, then stucco, and b/4 the last coat set up-cut back a thin channel and caulked again with urethane. Moisture cure so the bond was nice and tight.
If you stucco then cut, the thickness of the stucco and a half to 3/4 inset into the block would be sufficient and not compromise the block.
Not professionally done, but up on my roof for 20 yrs.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
DOH, I didn't think of applying stucco first, now that you say it seems so obvious. Thanks for your input.Todd
Use a diamond blade and cut as thin a kerf as possible. If you only go in 1/2", the block can saturate and moisture will bypass the flashing. You may be OK with the stucco over, but you won't undermine the block enough to cause concern.http://www.quittintime.com/ View Image
And I'll certainly defer to you Grant.
I can count on two hands the number of chimney's I've flashed.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Appreciate you advise...thanks. FWIW, I ran the chimney at the ridge, so it's a little simpler.Todd