Getting ready to do a residing project on a house with a fireplace/chimney. The exterior portion of the fireplance/chimney is block with a stucco-like finish (cracked and flaking off in places but that issue is not in the current program). My question is how to flash and/or seal the new siding and probably the existing sheathing (1/2″ plywood) against the masonry. My gut says to scrape off any flaky crude and simply caulk at the sheathing with urethane, then scribe the siding for a tight fit, and bed it in another fat bead of caulk. I generally don’t have a lot of faith in caulked joints, but can’t think of any alernatives. My manuals give plenty of detail on chimney/roof flashing systems but nothing for walls. Inspection from the basement indicates that the existing junction is leaking based on water marks visible on the inside of the band joist (below the fireplace/wall junction), as well water staining on the underside of the subfloor in the vicinity of the fireplace. Although it’s stained, I don’t see much evidence of rot however, I haven’t peeled off the existing siding yet. Current siding is vertical shiplap pine and unfortunately, the HO wants to replace with same. This is a 1970’s contemporary-style house in NH.
Thanks.
Replies
A piece of tin is customary in my area.
2"x 3" nailed to the studs right next to the masonry with heavy caulk on the 2" masonry side. Henrys works good. Then paper over the 3" side before your siding.
Be sure your masonry is clean before applying anything you expect to bond to it. That goes the same with the metal.
A swipe with some alcohol will work pretty good.