Wall thimble

[Firewoodjoe]

I just bought all new class a chimney and wall thimble. Just to be clear does on this wall thimble. The instructions are very vague and it appears you just frame the 14” hole for the thimble and leave it open inside between the thimble and the wood studs? Can the siding go up tight to the round hole? I can’t seem to find actual photos of a wood frame install. 

[Firewoodjoe]

I think I understand it. The wall thimble just creates the two inches of space you need from the combustible studs and gives a metal trim to run your j channel up to. 

[bluthum]

Many years ago I set one of those up exactly according  to provided instructions for a customer during a remo job. Home owner immediately started a big fire in the newly installed stove, about an hour later the siding started to smoke. We put it out easily and redid the set up how I forget but it never happened again. Place is still there I believe. Offhand I'd say absolutely not on wood up to the round hole, use metal of some sort. No doubt thimble designs have improved but I always err on the side of caution, over kill even, around wood burning appliances.

[Firewoodjoe]

Yeah I tend to go overboard. I’m actually removing a 3-4 foot square window that’s about 10 feet up
the wall to use for the chimney exist location. I may frame the window hole back in with metal studs and a brick veneer. Try and go all fire resistance material. Rock wool I think it’s called. I’ll do some more research before I tackle it. Better not rush something like that. Any other ideas would be great. Thanks. 

[Don P]

Google NFPA211 for some research,  generic drawings and code language, but it will defer to manufacturer's instructions.

I wear out the tech line. 

There was this one job, canadian windows and doors, high end multi point locks, set screws on the hinge pins concealed when closed. I'm showing the mason these bad ash doors, and the lock jams. Nothing from either side will open the door. I'm sitting in front of the door on the phone with the tech guys for hours over 2 days, I had a diamond wheel in the grinder as backup for day 2. I can now pick and reset one of those locks from the guts side, or I could  .

Anyway, they enjoy solving problems and are stuck at a desk, give em a call.

I think your plan is fine though.

[taylorsmissbeehaven]

I put a thimble thru a framed wall in my house in TN. I was the framer as well so I headed it off above and below and laid brick inside the wall. Ran my interior T&G up to it and chimney block on the outside. It was the only heat in the house so some nights it really roared! Never had a problem that I was aware of . One of the old timers in the area gave me the idea. Said most were done that way in the area. Brian 

[Firewoodjoe]

Ok. I’m making this to complicated on myself I feel. I tend to over think. I have the wall all framed in and house wrapped. I bought a piece of wood siding to just put in place of the old window. Figured I could use all the old vinyl siding. Well I can’t seem to figure out the best was to trim the vinyl in with the sheet of wood siding to be weather proof. Any ideas. Or should I just vinyl the hole window hole shut. Just curious what some of you think. Thanks. 

[Firewoodjoe]

I guess what I’m getting at is anything I use sheet wise. Like even brick veneer it won’t have the lip like a window has for the j channel to set up against. Will I have to trim the sheet in first then run the j channel up to that. 

[Firewoodjoe]

Flashing tape under the siding and J channel? Then j channel up to the sides and bottom, then z or drip edge over the top? 

[newoodguy78]

Flashing is your friend. At the top of the “patch” the flashing goes up under the existing and out and over the “patch”. At the bottom the flashing will go up under the “ patch “ and out and over the existing. If you don’t have access to coil stock and a break most any lumberyard should have 10’ prebent lengths available.

[Firewoodjoe]

I got it all done. Just did a combination of everything and added drip edge top and bottom. No water will penetrate and if it did it’s all sealed with 6” flashing and or tap. That stuff amazes me. Good stuff. Anyways I think I achieved the look of keeping a window, but being siding.