Stainless cover vs full chimney cap over masonry crown

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fire_man

Minister of Fire
Feb 6, 2009
2,534
North Eastern MA
Nice work! Please post lots of pics as the job goes along.
 

Kvic

New Member
Sep 12, 2021
75
Middle Tn
Couple of questions. More to come I'm sure.

1. All the estimates included pressure washing, do I need to do that before I start grinding the joints out?

2. Any tips on removing caulk from brick?
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
26,055
central pa
Couple of questions. More to come I'm sure.

1. All the estimates included pressure washing, do I need to do that before I start grinding the joints out?

2. Any tips on removing caulk from brick?
1. No not really but I prefer to. You don't want to do it after repointing.

2. It is a real pain and sometimes simply can't be done.
 

Kvic

New Member
Sep 12, 2021
75
Middle Tn
1. No not really but I prefer to. You don't want to do it after repointing.

2. It is a real pain and sometimes simply can't be done.
Thanks bholler. I've tried wire brushing some places with caulk, and the regular silicone type comes off with some effort, but they used a gray colored type that doesn't budge.
 

Kvic

New Member
Sep 12, 2021
75
Middle Tn
Got most of the old mortar off the brick and ground down some of the high spots, is it flat/clean enough?

Do I need to do anything else to the top before prepping for new crown? I was wondering if I should try to clear an expansion space around the whole flue tile, or will it be ok as is? I was considering filling the void next to the flue with rock wool (would do it all the way around if I need to create an expansion) and then using aluminum flashing as the bond break, overlapping two 20" wide sheets. Sill seal around the flue.

After reading through some more old threads, came across one on creosote that made me check inside the flue. I know I haven't had it cleaned in the 2+ years we've been here. When we got the estimate for install, they said they would clean it, and when they came back out to look at the flex liner said the installers would have done it if it looked dirty. Below are the pictures from the top and below. Not looking very clean. Is that creosote buildup on mortar, or all creosote in the close up?

IMG_3428.jpg IMG_3425 (2).jpg IMG_3432.jpg IMG_3432 - Copy (2).jpg IMG_3441.jpg
 

fire_man

Minister of Fire
Feb 6, 2009
2,534
North Eastern MA
What did you use to grind it down to brick? Looks Good.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
26,055
central pa
Got most of the old mortar off the brick and ground down some of the high spots, is it flat/clean enough?

Do I need to do anything else to the top before prepping for new crown? I was wondering if I should try to clear an expansion space around the whole flue tile, or will it be ok as is? I was considering filling the void next to the flue with rock wool (would do it all the way around if I need to create an expansion) and then using aluminum flashing as the bond break, overlapping two 20" wide sheets. Sill seal around the flue.

After reading through some more old threads, came across one on creosote that made me check inside the flue. I know I haven't had it cleaned in the 2+ years we've been here. When we got the estimate for install, they said they would clean it, and when they came back out to look at the flex liner said the installers would have done it if it looked dirty. Below are the pictures from the top and below. Not looking very clean. Is that creosote buildup on mortar, or all creosote in the close up?

View attachment 282446 View attachment 282447 View attachment 282448 View attachment 282449 View attachment 282450
I just use a sheet of plastic under the crown.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
26,055
central pa
That's one thing that might actually be easy. What are your thoughts on the flue and smoke chamber?
It's hard to tell from the pics but it doesn't look very dirty
 
If that was my chimney I would fill all the voids with type n mortar and slick it off before I started on a cap. The holes in the brick as well as the spot between the flue and the cmu. If the mortar seems to be falling into a never ending abyss stuff a little rock wool a few inches down and use it as a backer.

That's just what I would do... Maybe overkill.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
26,055
central pa
If that was my chimney I would fill all the voids with type n mortar and slick it off before I started on a cap. The holes in the brick as well as the spot between the flue and the cmu. If the mortar seems to be falling into a never ending abyss stuff a little rock wool a few inches down and use it as a backer.

That's just what I would do... Maybe overkill.
A flue tile should absolutely never be mortared in. The cores could be filled but there really would be no benifit.
 

Kvic

New Member
Sep 12, 2021
75
Middle Tn
It's hard to tell from the pics but it doesn't look very dirty
Thanks. It didn't look bad compared to some of the pictures I looked up, but when I zoomed in on the middle of the flue, it looked worse. I just don't have any experience so wanted to see what you guys with experience thought.
 

Kvic

New Member
Sep 12, 2021
75
Middle Tn
If that was my chimney I would fill all the voids with type n mortar and slick it off before I started on a cap. The holes in the brick as well as the spot between the flue and the cmu. If the mortar seems to be falling into a never ending abyss stuff a little rock wool a few inches down and use it as a backer.

That's just what I would do... Maybe overkill.
I was considering that where the dummy flue was, but didn't know if it was necessary since the crown will cover it all up.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
26,055
central pa
I was considering that where the dummy flue was, but didn't know if it was necessary since the crown will cover it all up.
Just make sure you cut out any bad head joints on the top course before you pour the crown. They are a real pain after.
 

Kvic

New Member
Sep 12, 2021
75
Middle Tn
Just make sure you cut out any bad head joints on the top course before you pour the crown. They are a real pain after.
My plan is to pressure wash the brick next, then grind out all the joints, replace cracked bricks and repoint, and then pour the crown.
 

Kvic

New Member
Sep 12, 2021
75
Middle Tn
Maybe expecting too much, but hoping someone might be able to give me an idea of mortar mix based on the pictures from the existing mortar. Based on what I have found online, and affirmed by the sales rep at the masonry supply, it's made with river sand. I asked if he thought type N or O for 1965 home, and he said probably type N because that's pretty much what they use these days. Trying to get this right so I don't have to worry about it again for a long time, and don't want to mess it up by using the wrong mortar mix. From what I've read and watched, short of sending it off to be analyzed, I can't know the exactly. Can't afford to send it off, so hoping the experienced might be able to shed some light, and send me down the right path.

First is a cross section from one of the joints I ground out. Second is the bottom a broken brick I took out to take on my journey to find brick. Third is a close up of existing mortar on the side of the house. Also added a picture of the brick I'll be using.

IMG_3445 (2).jpg IMG_3444.jpg IMG_3442 (2).jpg IMG_3443.jpg
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
26,055
central pa
Whatever river sand you have available in your area and grey mortar type n
Maybe expecting too much, but hoping someone might be able to give me an idea of mortar mix based on the pictures from the existing mortar. Based on what I have found online, and affirmed by the sales rep at the masonry supply, it's made with river sand. I asked if he thought type N or O for 1965 home, and he said probably type N because that's pretty much what they use these days. Trying to get this right so I don't have to worry about it again for a long time, and don't want to mess it up by using the wrong mortar mix. From what I've read and watched, short of sending it off to be analyzed, I can't know the exactly. Can't afford to send it off, so hoping the experienced might be able to shed some light, and send me down the right path.

First is a cross section from one of the joints I ground out. Second is the bottom a broken brick I took out to take on my journey to find brick. Third is a close up of existing mortar on the side of the house. Also added a picture of the brick I'll be using.

View attachment 282568 View attachment 282569 View attachment 282570 View attachment 282571
 

Kvic

New Member
Sep 12, 2021
75
Middle Tn
Whatever river sand you have available in your area and grey mortar type n
What ratio would you suggest? Searching the web for type n I see the most common ratio of 1 cement: 1 lime: 6 sand.

Is the portland/lime type n mix ok, or better to get everything separate and mix from scratch? And looks like a quarter ton of river sand is the least amount I can get local.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
26,055
central pa
What ratio would you suggest? Searching the web for type n I see the most common ratio of 1 cement: 1 lime: 6 sand.

Is the portland/lime type n mix ok, or better to get everything separate and mix from scratch? And looks like a quarter ton of river sand is the least amount I can get local.
3 to 1 sand to mortar mix. And yes buy mortar mix not cement and lime.
 

armanidog

Feeling the Heat
Jan 8, 2017
355
Northeast Georgia
What ratio would you suggest? Searching the web for type n I see the most common ratio of 1 cement: 1 lime: 6 sand.

Is the portland/lime type n mix ok, or better to get everything separate and mix from scratch? And looks like a quarter ton of river sand is the least amount I can get local.
If you have some leftover sand you can make a sandbox, fill some cat boxes, or spread it on ice during the winter. Do not add it to clay soil in a garden , you will end up with brick soil.
How many days/hours do you think it will take to do this job?
 

Kvic

New Member
Sep 12, 2021
75
Middle Tn
If you have some leftover sand you can make a sandbox, fill some cat boxes, or spread it on ice during the winter. Do not add it to clay soil in a garden , you will end up with brick soil.
Thanks for the ideas. Yes, I think I'll have some left over even with extra waste from the learning curve. If my calculations were right I only have about 65 square feet to repoint.
No one to play in a sand box, no cats, and only occasional ice, so I'll have to think of something. I may bag some just to have on hand should I need it in the future.
3 to 1 sand to mortar mix. And yes buy mortar mix not cement and lime.
Thank you again. So much to learn, so little time. I'm thankful for the knowledge base here and willingness to help. If I followed the info I found online I assume the mortar would end up being too weak, and more problems down the road?
 

Kvic

New Member
Sep 12, 2021
75
Middle Tn
Picked up the sand yesterday, and asked for type n portland lime mix, and this is what they gave me. Right stuff, or did I ask for the wrong thing. Don't see Type N on the bag, but it does have 32kg stamped on the side. According to the spec sheet it could be type o or n. The other side has Gray CLN (Cement Lime N ?) Was planning on calling the manufacturer to verify. IMG_3453 (2).jpg Holcim.JPG