Building a Cinderblock Chimney...

dkononczuk · Post by **dkononczuk** » Thu. Aug. 14, 2008 9:38 pm

I'm in the process of building a chimney, but before I start few questions.

The chimney will be going along side of my house where there is vinyl siding right now.
Should I remove the siding and stack the blocks flat against the house,
or keep the siding on, and leave maybe half inch space between the house and the chimney?

Also in either combination, do I need to secure the blocks to the house?

I'm a handy person, but I never had a pleasure to put a chimney,
all sugestions are welcome.

Dan

Devil505 · Post by **Devil505** » Thu. Aug. 14, 2008 9:49 pm

I had a block chimney put up by a professional mason who didn't remove the cedar shingles on the wall first. He just butted the block up against them. I recently had another mason tell me he should have removed the shingles & attached it directly to the plywood.
Then again, I think it was Yanche here who said that wasn't necessary & that butted against the siding was fine!

Moral of the story: I think it will depend on who you ask

(I would ask your town's building inspector to be safe)

gambler · Post by **gambler** » Thu. Aug. 14, 2008 9:58 pm

The siding should be removed and wall ties used to hold the chimney against the plywood. When the chimney is finished you put "J" channel against the chimney and re-install the siding.

EnergyAllStars · Post by **EnergyAllStars** » Fri. Aug. 15, 2008 6:37 am

I agree with gambler. . . . it would be a cleaner finished look. If I were building an exterior block chimney I would go the same route.

coalkirk · Post by **coalkirk** » Fri. Aug. 15, 2008 6:47 am

If you don't remove the siding, you must at least add some pretty beafy straps to hold the chimney to the house. In my job, I'm up on roofs alot (no, i'm not Santa) and every once in awhile I'll touch or lean on a chimney and it's very wiggly. One good shove and it would be on the ground.

huntabsarokee · Post by **huntabsarokee** » Fri. Aug. 15, 2008 8:00 am

I would definitely remove the siding. Besides a better look when finished off with J channel and attaching the block right to the house it will make for an easier job if you want to install new siding in the future. I would just cut the siding out at whatever width your finished chimney will be PLUS a little extra for the space the J channel will take up when you finish off the siding when the chminey is finished.

dkononczuk · Post by **dkononczuk** » Fri. Aug. 15, 2008 8:10 am

Thanks for the info...
I was thinking about removing the siding just for the cleaner look.
So, when it comes to securing the chimney to the house, what do I use
some kind of the straps going around the chimney and screw to the house?
And how far apart they should be placed?

Also would you add some kind of the insulation/water protection between the
chimney and wall?

Dan

CoalHeat · Post by **CoalHeat** » Fri. Aug. 15, 2008 8:29 am

Look at page 14.

http://books.google.com/books?id=TPEDU11XQg0C&pg= ... t#PPA14,M1

Yanche · Post by **Yanche** » Fri. Aug. 15, 2008 10:43 am

I'd remove the siding. Hopefully you will find Tyvek or something similar behind it. If not add some. If you have some choice in chimney location try to find one that will have a vertical stud within the width of the chimney. That way you can fasten the masonry ties into something more solid than only the sheathing. Be aware that over a long time period many of the cheap ties will rust and fail. Less of a problem where the wall tie is unlikely to get wet.