Question DVL to snout connection

[stoveliker]

I had an air leak where my DVL connects to the single wall (....) snout. That connection is inside my poured concrete.. (There are no clearance issues; within 2 ft all is stone veneer and concrete.)
I had patched it during the burning season with furnace cement to the point I had zero air going in and made sure that I had no change in CO readings.

Likely when moving the telescoping DVL in order to take it out for checking/sweeping mid season, the jiggling messed with the connection. None of the two "seams" were fixed with screws, it turns out.

The hole in the concrete is far larger than the pipe needs, at least at the place where the pipe comes out into the room.

I am attempting to redo this properly and have a few questions.

1. See the pics. There was this piece connecting the snout to the first DVL section. I didn't pay attention when I took things apart. Which way goes to the single wall snout and which way to the DVL?

2. I am hoping to put some screws in, from the inside to the outside (outside in is not possible because this is inside my poured wall) to fix these parts and stop their movement. Is that okay? (Normally screws go from the outside to the inside.)

3. There is about 2-3" of space between the bottom of my pipe and the concrete where the pipe comes out of the wall. What mortar should I use to build that area up to give more support to the piping? Preferably something I can get at a (orange or blue) box store premixed.

This is not my area of knowledge...

 

[begreen]

The right side image (second) looks more correct to me.

 

[stoveliker]

Okay, thanks.

Any concerns about screwing that right part into the snout from the inside?

 

[begreen]

That should be ok. Another option would be to pop rivet it with stainless steel pop rivets.

 

[stoveliker]

Good point, that's what I'll do.

That leaves the third question above (about what material to use to fill the top large hole in the concrete).
I guess @bholler would know but he's offline at.this time.

Anybody else with more insight than me?

 

[begreen]

How large of a gap needs to be filled?

 

[stoveliker]

The gap is 2.5" larger diameter where the pipe enters the concrete than the OD of the pipe. A bit uneven 2-2.5".

 

[begreen]

That's a good sized gap, too large for some rope gasket. I'm not sure I would mortar directly to the snout. It is bound to move a bit with cleaning and expansion during heating.

 

[stoveliker]

Yes. The hole is conical (?); it is larger at the inside edge of the concrete wall than it is farther in. The snout ends somewhere halfway in the wall. There it's decent (0.5-0.75".gap around the end of the snout).
At the inside surface of the wall it's at least 2".

I'm afraid I'll have to do concrete (i.e. mortar plus gravel), but don't know if it needs to be special because of the temp. The snout is single wall, so is that connector piece in the image above. From that on towards the stove it's double wall.

It appears others have added concrete before at this end but that broke off. Likely because adherence to the concrete of the wall was compromised due to previous leaks; wall concrete is black/brown at the bottom, could be rust or creosote. So I'll be grinding that away to create a fresh surface.
My pipes are fine. I think that leak happened before the chimney got lined.

I would like a suggestion of what (hopefully box store premixed) stuff I could use for this

 

[bholler]

Yes. The hole is conical (?); it is larger at the inside edge of the concrete wall than it is farther in. The snout ends somewhere halfway in the wall. There it's decent (0.5-0.75".gap around the end of the snout).
At the inside surface of the wall it's at least 2".

I'm afraid I'll have to do concrete (i.e. mortar plus gravel), but don't know if it needs to be special because of the temp. The snout is single wall, so is that connector piece in the image above. From that on towards the stove it's double wall.

It appears others have added concrete before at this end but that broke off. Likely because adherence to the concrete of the wall was compromised due to previous leaks; wall concrete is black/brown at the bottom, could be rust or creosote. So I'll be grinding that away to create a fresh surface.
My pipes are fine. I think that leak happened before the chimney got lined.

I would like a suggestion of what (hopefully box store premixed) stuff I could use for this

I would rivet the piece in place. Then stuff the space with ceramic or mineral wool. I usually leave the insulation about 3/4" back then fill the rest with mortar. I usually use chambertech. A wrap of flat gasket around the snout helps minimize cracking if your using regular mortar.

 

[stoveliker]

Okay, thanks. Much appreciated.

 

[stoveliker]

Riveted the connector piece to the snout - with a glass fiber flat rope as it was not tight enough to my liking - and on the other side to the double wall pipe.
The snout was a lot harder steel than the connector piece, and that was a lot harder than the double wall ..

Drilling was a bit awkward in the snout; angle piece on the drill and a stubby 1/8" bit, but it worked. (Okay, I broke two bits...)

Nice and sturdy now.

Next is the rockwool and mortar.

I'll connect the telescoping pipe later when the humidity goes down.

 

[stoveliker]

Follow up question.
I would like a new collar (i.e. my masonry skills are not that great ) around where the double wall Duravent enters the wall. Aesthetics only.

I can't find such a collar in the Duravent catalog.

Would the 7" version of this one fit?

Single Wall Stove Pipe Trim Collar for Flue Opening - Rockford Chimney

Our Single Wall Trim Collar is made of 22 gauge steel and is used to cover the excess area around the flue opening for an attractive finished look.

www.rockfordchimneysupply.com

If not, any suggestions?

 

[bholler]

Follow up question.
I would like a new collar (i.e. my masonry skills are not that great ) around where the double wall Duravent enters the wall. Aesthetics only.

I can't find such a collar in the Duravent catalog.

Would the 7" version of this one fit?

Single Wall Stove Pipe Trim Collar for Flue Opening - Rockford Chimney

Our Single Wall Trim Collar is made of 22 gauge steel and is used to cover the excess area around the flue opening for an attractive finished look.

www.rockfordchimneysupply.com

If not, any suggestions?

7" will be close but I don't know if it will fit perfectly. I typically cut a flat 6" one to fit.

 

[begreen]

Shouldn't the DVL stay outside of the wall with the thimble being proud of it?

 

[stoveliker]

I don't know, you tell me.

As I noted in the first line of post 1 and the first line of post 9, the snout ends someplace inside the concrete wall. So now the DVL is riveted to the snout, and that rivet is located inside the wall.

The wall is concrete, and all clearances were met for single wall. Now it's double wall. So it's not a clearance issue.
Double wall pipe within concrete can be a durability issue though. (?)

This was all done by a supposedly reputable, certified company here (who I asked to change from single wall to double wall stove pipe).
Evidenty their mortaring was not done well as it fell out.

 

[begreen]

If the wall is entirely concrete then it's not a clearance issue.

 

[stoveliker]

It is (within single wall pipe clearance distance).
Just concrete with brick veneer.

Will be taking that brick veneer off and tile it.

I was thinking you were hinting at a snout connection to pipe needing to be "visible", i.e. on the room side of the wall penetration.

 

[bholler]

It is (within single wall pipe clearance distance).
Just concrete with brick veneer.

Will be taking that brick veneer off and tile it.

I was thinking you were hinting at a snout connection to pipe needing to be "visible", i.e. on the room side of the wall penetration.

The snout should come out of the wall yes. But it really won't be a problem. The only possible issue would be rust on the outer wall.

 

[stoveliker]

The snout should come out of the wall yes. But it really won't be a problem. The only possible issue would be rust on the outer wall.

Hm, interesting.
From the back (farthest from the home) of the liner it's 18" or so to the tip of the snout.
Then it's 8 more inches to the inside face of the concrete wall.
So the snout is too short. But I'm not sure if 26" long (well, 26" minus half the diameter of the liner, so about 24" long) snouts exist?

We'll see how it holds up. So far (2 yrs) it's been fine.
Given that the company who put in the double wall for me (as I was not sure how to connect it to the single wall snout inside the concrete at the time) said that the liner had been completely cemented in at the top and they were not able to pull it up a bit (it seemed to have sagged a bit, evidenced by a slight downward slope of the horizontal section...) I hope the snout never needs replacing, but if it does:

--> what are the longest snouts available? Or can they be made to custom length from stainless steel pipe?

 

[bholler]

Hm, interesting.
From the back (farthest from the home) of the liner it's 18" or so to the tip of the snout.
Then it's 8 more inches to the inside face of the concrete wall.
So the snout is too short. But I'm not sure if 26" long (well, 26" minus half the diameter of the liner, so about 24" long) snouts exist?

We'll see how it holds up. So far (2 yrs) it's been fine.
Given that the company who put in the double wall for me (as I was not sure how to connect it to the single wall snout inside the concrete at the time) said that the liner had been completely cemented in at the top and they were not able to pull it up a bit (it seemed to have sagged a bit, evidenced by a slight downward slope of the horizontal section...) I hope the snout never needs replacing, but if it does:

--> what are the longest snouts available? Or can they be made to custom length from stainless steel pipe?

I have a 36 and a 48 sitting in the shop but they are custom order. Usually I just add on stainless pipe

 

[stoveliker]

Okay. I'll keep that in mind if I ever have to change things: stainless single wall (plus ceramic insulation) until the face of the wall, and then transition to double wall.

I might be able to rivet an extension piece of pipe to the existing snout, if I have to do this. Only have to work out the length of the telescoping part to ensure I can fit everything together then.

Much appreciated.

 

[begreen]

I was thinking you were hinting at a snout connection to pipe needing to be "visible", i.e. on the room side of the wall penetration

I was, that's the only way I have seen it done, but Ben has seen many times more than I. Rockford sells a 22" snout, but it sound like that would not quite make it.

Chimney Liner Tee Connector Long Snout 22 Inches in Length - Rockford Chimney

Need more tee length? 22" Quick Connect Snout for your Tee Body and Clean Out Cap. If you need the tee to be less than 22", simply cut it with a hack saw.

www.rockfordchimneysupply.com

 

[stoveliker]

It was 50something today, the low for tonight will be 36. 51 now .Freeze warning. Tomorrow 59.

But I did a small fire to check the piping. First a bit of kindling with some noodles, got it going then choked it so it smoked a lot Nothing came out of the seams visibly. Smelling with my nose almost touching, nothing either.

Then I started a fire with 4 splits and some uglies. Maple and some oak. Ran it hot. No air sucking in anywhere that I could detect.

All seems good. New cat thermometer with numbers. Closed the bypass when i thought it was hot enough even though the thermometer said 100 F. It lit off (glowing) within two seconds.

Stove is A bit stinky because of the dust in the convection deck that I can't get away (see my other thread).

Likely the only fire until the second week of December if I believe the long term forecast. (Solar electrons will be running through the minisplit in the mean time.)
But it's nice to know that all works before I really need the heat.