Clearance to ceiling ?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.
Brian VT

Brian VT

Minister of Fire
Jul 30, 2008
817
Southern VT
Newbie here.
I searched here and manufacturer's sites and cannot find this info. Sorry.
I want to install an insulated metal chimney through my basement wall.
I'd like the outside T as high off the ground as possible.
How close can I get to the ceiling inside ? I'll use insulated pipe inside also.
If this is the 4000th time this question has been posted then please point me to an old post.
Thanks.
 
I would think it would be the same as the clearance spec to the wall. Do you have that spec from the stove and pipe? 8 or 9"...
 
18" minimum.
 
If this is double-wall interior pipe like Duravent DVL I believe it is 6" from the wall and 8" from the ceiling.

Edit, cross posted with BB - Bart is this in error for double wall? I was just quoting from the DuraTech manual.
 
18" is for single wall connector pipe.
 
My plan is to come through the cinderblock wall, 8"+ below the ceiling, with insulated pipe and mount an insulated tee (with cleanout) to turn down to the stove since they don't make an insulated 90.
Sound okay ? Not the prettiest setup but I figure I've gotta clean the horizontal from the inside anyway so...
I just picked up an 8 yr. old black VC Resolute, in good shape, for $450. Seemed like a good price to me. I think I could sell it for that if I don't like it.
 
Brian, once you are inside the house you will be using a different type of pipe. It will be interior grade double wall pipe for which they make 90s. (Simpson DVL pipe) You will need a thimble for the wall and finishing collar to transition from the class A stub to the DVL interior pipe. Download the Simpson installation manual for DuraTech 5-8" and go to page 17 and 18 for some instructions and visuals.
 
Thanks BG. My plumber friend will get the pipe for me and he said they (Metalbestos) didn't make 90s.
I'll look into it some more. My wife would prefer black inside so your suggestion would help in that regard also.
 
I'm guessing your plumber friend is also thinking of running class A inside. Get a Selkirk (Metalbestos) catalog. The installation is similar to Simpson. Same idea, you transition to the interior pipe at the thimble. Selkirk makes interior double-wall 90s too. They are in black. Here is a page listing the pipe and accessories:

http://www.ventingpipe.com/display.cfm?categoryID=879
 
Jeez you're good ! I didn't find that stuff on Selkirk's site.
You da man. Thanks again.
 
Brian VT said:
My plan is to come through the cinderblock wall, 8"+ below the ceiling, with insulated pipe and mount an insulated tee (with cleanout) to turn down to the stove since they don't make an insulated 90.
Sound okay ? Not the prettiest setup but I figure I've gotta clean the horizontal from the inside anyway so...
I just picked up an 8 yr. old black VC Resolute, in good shape, for $450. Seemed like a good price to me. I think I could sell it for that if I don't like it.
Click to expand...

Hi Brian, we are newbies and in the same boat as you. Going through cinder block in the basement. What have you been hearing about cold chimneys and difficulties getting a fire started? One guy said he runs a blow dryer in his stove for fifteen minutes to warm the pipe. Another guy said he gets smoke in the basement for about a half hour when he lights a new fire.
 
I'm thinking I won't have a great draft either.
If my orig. setup doesn't draw well I'll extend the chimney above the ridge.
After that I may build an enclosure around the chimney. It's on the North side of my house too, which won't help matters.
If that doesn't help I guess I'll be doing the hair dryer too.
Might have to install a chimney fan ? My buddy says he doesn't like that idea but I may research it if it comes down to that.
 
crack a window or exterior door close to the unit just a couple inches about 3 to 5 minutes before you start the fire, this will releave some of the negative pressure in the basement (caused by stack effect in the house) and the flue will start to pick up its draft , then light the fire with a rapid heat source such as small split kindling , or supercedars , or similar type firestarters. once the draft starts moving(which will be faster than it would be without the opening) the opened door or window can be closed again.

stack effect is easily the number one cause for poor startup draft in basement chimneys. this is caused by the relatively warmer air than outside of the house rising as it would in a chimney.

now, with the top of the house closed off by the roof , the warm air is stopped at the top of the dwelling. this creates a moderately higher air pressure high in the house which becomes lower as you decend in the house, somewhere between the roof and the basement floor is a level plane where the air pressure in the house and outdoors is identical. this is called the "zero pressure plane"

a chimney coupler located below the zero pressure plane will have a lesser standby (or cold ) draft than one located above this plane. basement couplers are always well below this plane , hence the sluggish startup performance in most basement chimneys compared to upstairs.

this effect generally does not cause issues when the unit is up to temperature except in extremely tight houses or with uninsulated exterior chimneys.
 
So...my buddy that will help me with the chimney still wants to do the Class A inside because, he claims, we can be 2" below the interior ceiling which will keep the T support outside a bit higher off the ground. He says we can scuff the interior pipe and paint it black if my wife thinks it's not pretty enough for our "shack".
Is the 2" clearance rating valid for a combustible surface above a horizontal run ?
 
If you went with your buddy's plan, how are you going to connect the stove to the class A? As far as I know they don't make a class A 90 deg elbow, so you still have the same problem. How close is the T to the ground if you are 8" below the ceiling using double wall?
 
BeGreen said:
If you went with your buddy's plan, how are you going to connect the stove to the class A? As far as I know they don't make a class A 90 deg elbow, so you still have the same problem. How close is the T to the ground if you are 8" below the ceiling using double wall?
Click to expand...

He wants to use another T as the 90 to turn down to the stove. I assume he'd use single wall or DVL below that.
If we're 8" below the ceiling we'd be @ 14" above the ground outside.

I was just thinking...I don't know how big a hole I need in the cinder block wall for the thimble. That may have some bearing on this ?
 
No offense meant to your buddy, but this sounds like an expensive kludge to gain a few inches. If you want to gain a few inches more space under the exterior tee it would be cheaper and cleaner to excavate a gentle depression on the outside.
 
I agree. I was just kinda looking for some good reasons to give while trying to talk him out of his idea without offending him.
He is really excited at his idea of having a cleanout inside.
 
He will have it. Just detach the elbow from the thimble.
 
I've got better measurements now.
These are based on cutting the 8" hole through one 8" high cinder block rather than getting into more than one row.

The horizontal run will be 8"+ below the interior ceiling and 7" above the ground outside. This would put the bottom of the T (cleanout) at 4 1/2" above the ground.
I'm starting to think I should hang the chimney from the roof support in my eave rather than support it from below. I'll have 11' of chimney hanging and 6' above it.
Sound right to you ? If so, would I want to rig something to keep the snow from piling up around my cleanout or will it get melted out quite a ways from it ?
 
I've got my (Selkirk) parts list together but the places I've shopped online only seem to carry the basics.
Anyone know a source with all the goods ? Preferably in the northeast USA.
I think my buddy's supply house may only carry the commercial stuff (no interior black double wall). That may be why he was suggesting class A inside.
 
I did see them but figured the shipping from CA to VT would be brutal. I guess I should get a quote, though.
 
I have the same set up with simpson double wall pipe (8 inches from ceiling) building inspector here said I could have gone 2 inches to the ceiling you can put your hand on the pipe even with stove @ 600 F maybe he is right I think I will stay w/man. specs though
 
Status
Not open for further replies.

Similar threads

P
Question on roof penetration in a shed / non-lovjng area
Replies
16
Views
986
The Hearth Room - Wood Stoves and Fireplaces
begreen
begreen
C
Homestead install alcove ceiling
Replies
6
Views
573
HearthStone
CarolinaPhil
C
F
Another alcove build advice and input
Replies
21
Views
1K
The Hearth Room - Wood Stoves and Fireplaces
U235
U
MedicineMan4040
Big day draws near
Replies
8
Views
539
The Hearth Room - Wood Stoves and Fireplaces
MedicineMan4040
MedicineMan4040
R
Stainless pipe through floor joist question
Replies
2
Views
929
The Hearth Room - Wood Stoves and Fireplaces
racer765
R
Top Bottom
Back