Exterior chimney thimble

New Ideal Steel should be ready in a couple weeks, and I'm having a little trouble finding a contractor (story of my life) to put in a chimney. Seems the folks around here want to sell you a stove first, or are too far away. So I'm thinking I may take the old approach where it's better to beg forgiveness than ask for permission with the insurance company and do it myself. I'm going straight out the wall and up with the chimney.

Question for the gurus here is probably silly, but I'll ask anyway.. On the thimble install, should I frame the thimble in or just screw into the sheetrock inside? That seems pretty weak to me.. I have to be missing something obvious. Outside, I have vinyl siding over foil/foam insulation board, over t-111 siding. My thought was to strip down to the old siding and affix to that, and get some j-channel to make a trimmed looking square of the current vinyl just over lapping the edge of the thimble square

Any thoughts or criticism would be appreciated!

 

If you want to be good with your insurance company, you should at least comply with NFPA 211. That should be a good starting point...

NFPA 211: Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances

 

If you buy a "through the wall" kit, it will have detailed instructions on what to do...at least my Supervent kit did.
Here's the install info...https://hw.menardc.com/main/items/m...nedInstallationinstructionswarrantylowres.pdf

 

Assuming we are talking about a twin- wall, stainless steel, insulated chimney, the brace outside the house that supports the 'TEE' will bear all the weight of the chimney. So the thimble does not need any structural support at all. As was already mentioned, just buy the kits available to do this and all will be fine- they have been making these things a long time and they are quite nice, robust and work well.

I have both a Champion and DuraVent chimney and of the two, much prefer the DuraVent due to the way the pieces couple. The Champion uses small sheet metal screws to secure the individual sections while the DuraVent has a very large screw- like affair (Easy Boys!) that interlocks the sections- much more secure, square and easier to use. Also, they make outside 'V' rings that lock the joints together extremely well but are still easy to remove.

Brian

 

Yep.. what he said. ^^

I installed the insulated DuraVent here, and couldn't be happier with it.


My install went through cinderblock, so can't really help with your original question BigPapi

 

NFPA code and the Supervent PDF are exactly what I need - thank you!

Duly noted as well on Champion vs Supervent - I actually had an order queued for Champion pipe, but will now reconsider. Twist lock rather than sheet metal screws sounds like the way to go.

Thanks all!

 

Supervent uses the twist lock (with a clamp over the seam then) and is on sale at Menards right now...about $63 per 36" section of 6" class A...and the through the wall kit is $260. This is after rebate...which is store credit, and I know you don't have Menards there, but you could just sell the rebate credit here on FHC just like someone else did recently.
https://www.menards.com/main/heatin...359-c-6894.htm?tid=8712773648105163605&ipos=5
My inlaws built a new house a couple years ago, I put up their new chimney using Supervent from Menards sale (it was on sale, plus 11% rebate too) cost about $500 total for a 15' chimney up through the roof...and that includes that the added optional shields and insulation too.

 

One piece of free advice, put your wall thimble up high enough that the stovepipe can come out of the stove and 45* up to the wall thimble...it'll draft much gooder than using 90*s.
Allows you more options with any future stove install that happens down the road too (not limited by height)

 

Despite not being future proof, we're actually going straight out the wall off the back of the stove. I hope the IS treats us well, because it's going to be there for a while.

 

How long will the horizontal be? Horizontal kills draft and makes for smoke spill-out when reloading...try to put at least some rise on it...dead flat is gonna cause trouble...

 

Doesn't the IS have the option of going top or back vent?

 

Yes.

 

So there must be something about the house that makes BP want to rear vent

 

I can't answer for him, but I figure you are correct.

 

maybe just the least amount of fittings?...

but one thing I do know first hand, the IS is prone to smoke spillage with the big door...
on a reload, i try to get all the wood ready to go in the box then open the door and get it in quick. or close the door between grabbing arm loads. once the flames start, the smoke comes fast and hard.

 

The horizontal run will be pitched at 1/2" per foot, but won't be too long. With rear heat shield kit installed, clearance to combustibles is just 6". From there through the wall and figure 10" or so to clear the short eave without needing to cut. I haven't gone up and dropped a plumb line yet, but the overhang at that part of the house doesn't look more than 8". I'm figuring 20" or less horizontal run, not including the collar.

As for why, I call her Mrs Papi. (Also wanted to minimize joints/elbows.)

 

Can't wait to see the action pics of the new stove, Big Papi !

 

X2......and the action pics of this chimney install

 

Well, I finally got a guy out to Have a look. Not interested in the job, too close to electrical drop off the pole across the street. Looking at it, I can't say I blame him. It would be pretty tight work going under the wire. Looks like a call to Eversource is in order, to see what they think of taking up some slack and moving the drop a few feet. This job may get a lot more expensive.