New Guy, Questions - Sorry!!

[Midway43]

I have been lurking for a while now. I just wanted to run this by everyone to see if there are any red flags. I know you get a lot of these posts and I'm sorry. I just want to make sure before spending money.

Right now I have an open fireplace that I want to put a wood burning insert. I have decided on the FPX Large Hybrid Flush. It is large and has the biggest glass area(wife wants that). The chimney is in the middle of the house. I was not going to insulate the 6inch liner. I got up on the roof and measured and the chimney is 7inch by 7 inch square. It is also 19ft from the top to the bottom which I am assuming is the smoke shelf.

Would a 20ft liner work? How hard will it be to put a 6 in ID liner through a 7x7 square? I plan on doing the install.

Can the surround be altered? The surround is pretty plain. I was thinking about putting some 1in rectangle tubing behind it. basically an outline of the edge to add depth. This way it doesn't look like cheap thin metal. Or I might have it hang out an inch.

The reason for getting an insert is to cut down on oil costs. I was hoping to be able to fill it before bed at around 11pm. and fill it again in the morning around 530-6. I would think that it would go out while at work between 7am and 5 but i'll light it again at night.

The next issue is wood. I have 1 cord of wood that has been sitting for 2 years. I just purchased about 7 cords of logs that need to be cut and split. It is supposed to be 2-3 years old but... We will see. It is the same place that the local landscapers buy and then split and sell so not sure how dry it will be.

thanks

 

[bholler]

Really 7x7 on an open fireplace did it work at all?. i really feel that all liners should be insulated for safety code and performance reasons but in your case that would mean breaking out the old liners if it is 7x7. 20' might work but i would order more. you can absolutely modify the surround. and no it will not be dry i can almost guarantee.

 

[stoveguy2esw]

Really 7x7 on an open fireplace did it work at all?. i really feel that all liners should be insulated for safety code and performance reasons but in your case that would mean breaking out the old liners if it is 7x7. 20' might work but i would order more. you can absolutely modify the surround. and no it will not be dry i can almost guarantee.

interior chimney isnt going to suffer cold as bad as an exterior one , with a 7x7 he should be ok with a blockoff plate to hold some heat in the air space between the flue liner and the tiles i suspect

 

[bholler]

interior chimney isnt going to suffer cold as bad as an exterior one , with a 7x7 he should be ok with a blockoff plate to hold some heat in the air space between the flue liner and the tiles i suspect

I agree that it is not as important for performance on an interior chimney but it will still help allot and unless the chimney has proper clearances to combustibles insulation is required by code. On an interior chimney you need 2" from the exterior of the masonry to any combustibles

 

[Midway43]

I agree that it is not as important for performance on an interior chimney but it will still help allot and unless the chimney has proper clearances to combustibles insulation is required by code. On an interior chimney you need 2" from the exterior of the masonry to any combustibles

2" clearance. Is that from the chimney or the outside of the stone? I have a 7x7 square chimney. Around that is a 41" x 24" concrete and stone. Do I need 2" from the outside of that or from the 7x7 inside? I haven't looked but I would assume that they masonry has to be connected to the frame of the house somehow. right? It wouldn't be freestanding with 2" of space all around it.

7x7 chimney didn't work too well. Fire alarms were going off easily.

stoveguy, when you say blockoff plate, do you mean the one by the damper that will be taken out or the plate at the top of the chimney?

 

[saichele]

Stuffing the 6" liner down the 7" chimney is going to be tight. To the extent you can, look up and down for any kind of obstructions or misalignments.

Insulating is better, but not required.

As to the length of the liner - having extra is a drag, but coming up short isn't great either. You could go for 20' of flex, then add on rigid stainless if you were short. But that takes time and is a hassle. I'd get online and just get the 25' kit.

Steve

 

[Midway43]

I have looked down it with a flashlight. No obstructions or misalignments could be seen. It is straight down.

 

[claydogg84]

Hopefully the mason that laid in the flue tiles did you a favor and cleaned out the access mortar. If there is nothing visibly hanging out in between the tiles you should be fine. A friend had an issue because one of the tiles wasn't perfectly aligned with the rest. And also, any logs - I don't care how long they've been sitting, will not dry unless split and stacked. I did a pour down insulation on my liner because I also didn't have quite enough room for the fiberglass wrap. Good Luck!

 

[brenndatomu]

Get a piece of 6" stove pipe or round duct, couple to 3' long, see if you can lower it down through the flue. That actually would be a hair smaller than a 6" liner. Likely there is mortar squished out between the tile joints that will make it tough to pull a liner in, especially with insulation.

 

[joes169]

Really 7x7 on an open fireplace did it work at all?. i really feel that all liners should be insulated for safety code and performance reasons but in your case that would mean breaking out the old liners if it is 7x7. 20' might work but i would order more. you can absolutely modify the surround. and no it will not be dry i can almost guarantee.

That was my thought as well, the flue is greatly undersized for a masonry fireplace, someone didn't do their math correctly when thy built it.

The old standard rule for open masonry FP's is 10:1 ratio, fireplace opening (W x H) in square inches : interior area of the flue.

Assuming a modest 30" wide opening, the height would only be 16", which would have other issues, as well as look crazy......

 

[bholler]

Insulating is better, but not required.

Not true it is required with out proper clearance and if you read the fine print in every case i have checked it voids the ul listing if used with wood and un insulated. Now in this case with that much masonry surrounding it i seriously doubt it will be a problem but in order to be to code and ul compliant it should be. This would be one of the few cases that i would let it slide though if necessary due to the massive amount of masonry.

 

[Midway43]

The open fireplace is 41" wide x 31" tall.

The current chimney is 7x7. It is inside a bigger 12x12 one. the extra space is filled with what looks like concrete. I have no idea why. I would assume it goes all the way down. is that normal?

The other chimney for the furnace is 12x12

 

[bholler]

Are you sure you are looking at that right? a 12 x12 would be hugly oversized for just about any furnace and a 7x7 is massively undersized for that fireplace in fact i didn't do the numbers yet but thats a big fire box i think a 12x12 is probably small to. Is there any way you have the 2 mixed up?

 

[joes169]

The open fireplace is 41" wide x 31" tall.

The current chimney is 7x7. It is inside a bigger 12x12 one. the extra space is filled with what looks like concrete. I have no idea why. I would assume it goes all the way down. is that normal?

The other chimney for the furnace is 12x12

For that opening, it should have a 13" by 13" flue liner.

As for the "double layer", I would assume the bigger is just a small section of "dummy" flue at the top, so all the flues appear the same size as they exist the chimney cap, for visual reasons........

 

[HotCoals]

Some pics would be good here.

The current chimney is 7x7. It is inside a bigger 12x12 one.

 

[Midway43]

Are you sure you are looking at that right? a 12 x12 would be hugly oversized for just about any furnace and a 7x7 is massively undersized for that fireplace in fact i didn't do the numbers yet but thats a big fire box i think a 12x12 is probably small to. Is there any way you have the 2 mixed up?

I am sure that the 12x12 was the furnace. While I was up on the roof I could feel the warm air. There was no fire in the fireplace. The other one, the 7x7 has to be the fireplace. There is no chance that the furnace and the fireplace use the same one right? Especially with a second flue right there. Nah. The fireplace is to the 7x7 side. I know the furnace is on the other side. And also there is an ash clean out at the back of the fireplace. It is definitely on the 7x7 side.

I might be able to find out more info about the fireplace tomorrow. My dad built the house. I bought it off my mom a few years back. I can ask her.

 

[Midway43]

Some pics would be good here.

From up on the roof? That will have to wait until the weekend. It is dark when I get home.

 

[bholler]

I would double check that i cant say you are wrong because i am not there looking at it but it really would be totally wrong and backwards if it is true

 

[Midway43]

I would double check that i cant say you are wrong because i am not there looking at it but it really would be totally wrong and backwards if it is true

I'll check this weekend. I'll have my wife wave something around from the bottom while i'm on the roof. The house was built in the 70s if that matters. One story rancher. We never used this fireplace when I was growing up. We had a separate wood stove and also a wood furnace downstairs. They both had their own chimneys separate from these. The wood furnace chimney was taken down years ago. It was on an exterior wall.

 

[Midway43]

I just went down in the crawl space, I do think I have it backwards. I'll have to look better this weekend.