Is a clean-out necessary?

[CarrieP]

Hello, and thanks in advance to anyone who can help. First-time home buyer, first-time wood stove purchaser, and soon-to-be first-time regular wood stove user here!

The house is a 2000 sq ft two-story 1910 farmhouse in central Virginia. It doesn't get super cold here and though the house is not insulated at all, I plan to do that in the future - maybe straw bale. I also hope to install a heat pump and use the wood stove as backup. There is an interior masonry chimney that hasn't been used in at least 30 yrs so I'd like to use that. I'm told it was damaged in the 2011 earthquake and was repaired... There were stray bricks in the chimney, so that tracks.

I haven't been on the roof yet but I busted into the chimney through a sealed up thimble, and it looks like it's in decent shape. The flue is about 8"x7". The top of the thimble is 25" from the hearth and I'd like to avoid putting in another thimble higher up.

I'm excited about the catalytic models for the air quality and efficiency, and would rather undersize the stove due to the info above (though I've read it's better to make smaller fires in a larger stove than really work a smaller stove). At the store the salesman pushed the $3600 Jotul F 445 Holliday, which does seem like a good fit since it's appropriately sized and has a rear vent option. It also has a short leg option - the height with the short legs is 26.75, so if I replace the current hearth (2 stacks of bricks) with this stove board (https://www.efireplacestore.com/hyc-t2ul3242ww-1c.html) and one layer of cement board, I should have the necessary 1.6 R-value within the limited available space.

I can't find an inspector who is available before may, and we don't currently have heat in the house so I'm anxious to get this started, and the plan is to do as much as possible ourselves, including sweeping it and hopefully installing the liner and stove.

Questions:
1. Is there a different model I should consider? Stores around here don't have many options, but I'd love to find something cheaper (maybe wishful thinking...)

2.Is an insulated liner necessary for safety reasons? The manual doesn't require it, and there's not a lot of space in the flue to work with. Can I get away with an unlined liner like this? https://www.northlineexpress.com/6-...wall-liner-kit-with-tee-sn625k-tee-19742.html

3. The Holliday's manual says that: An airtight clean-out door should be located at the base of the chimney. There is no clean-out in this chimney, and the crawlspace of the house is about 12" tall, maybe 18" between joists. Attached is a photo I took of the base of the chimney, where there is a thimble at dirt level. Should that be sealed? I'd rather not have to empty the chimney from there. Can I instead put a cap on the liner tee (though if I did, I don't know how I'd empty it)? I'm confused about what my options are here.

Thanks so much, this community is awesome, really appreciate any insight.
Carrie

 

[Bristlecone]

1) I have a large stove and a small stove. I prefer the large stove because I can have a small, slow burning fire in it, but can put in more wood to get a hotter burn = more heat. You will be happy with whichever you chose.

2) 1 of my stoves has insulated pipe and the other does not. I guess insulated pipe is safer, but when I installed it, the selling point was that it kept heat in the flue and that reduces creosote build up

3) Neither one of mine has a cleanout and the chimney cleaners have no issue with it. If you don't have a straight shot from the wall to the stove ( elbows in a "Z" shape ), the cleanout is a good idea. If the flue comes directly from wall to stove, it's not necessary

 

[all night moe]

An insulated liner is better than non insulated. It'll help draft on milder days.

Use modern insulations over straw bail. Straw will break down and rot to dust.

With a non insulated house, I'd buy the largest easy breathing Stove I could find.

 

[CarrieP]

Thank you @Bristlecone and @allnightmoe.
I'm going to buy an insulated liner. Got up on the roof and the flue is only 8.5x8.5 inside, and there is a fair amount of mortar sticking out. (Photo attached.) I'm finding mixed opinions on whether an insulated flex 6" liner (OD 7.25") will fit. I would think it would, but it's a $1500 mistake if I'm wrong.

Is 6" rigid insulated liner a better bet? I need to extend the chimney with Class A pipe 40" above the end of the chimney, but I don't think that will impact the liner I use since I'll have to use a transition anchor plate whether I use flex or rigid.

Thanks again!

 

[weee123]

You have 5/8” of clearance on either side of the insulated liner i see no reason why it wouldn’t fit.

Before you install it, I would make sure the inside of the chimney has no creosote or anything and is clean and free of debris.

As for the cleanout, you should be running the liner to the face of that thimble and connecting your stove pipe to the liner. When you sweep down from the roof, after you finished you can take the stove pipe off and clean out the junk at the bottom of the liner. That’s what I would do.

What’s the diameter of the thimble into the chimney?

 

[CarrieP]

It's been said on here that there's no way a 6" insulated liner fits into an 8x8, so I wasn't sure if the extra half inch would make a difference.

Copy, I'll brush the inside of the chimney with a metal brush, since it's unlined brick and looks like it hasn't been cleaned in 100 yrs (which is technically possible.)

Re: the cleanout - thank you! That sounds very doable. I'll make sure the tee cap is tightly fixed to the bottom of the tee.

The diameter of the thimble is 6.25". I haven't bought the materials yet, but I'm thinking I need to buy the insulated liner with the tee and a 10" snout, and the snout would go through the thimble. And then the stove pipe will go over the outside of the snout, up to or perhaps through the thimble.

 

[Bristlecone]

Unless I missed something here, it looks like you need to changeout the thimble, then you are good to go and install an insulated pipe

 

[EbS-P]

The F445 is a brand new stove. I have not read any reports yet. Do yourself a favor and put a thimble up higher. That way you can choose any stove you want. I’d get something less radiant that could be loaded n/S.
Code will require an insulated liner.

To answer your original question no you don’t need a clean out as you can vacuum out the debris through the thimble but that means taking the interior horizontal stove pipe out.

I don’t have a good reason the seal the crawl space clean out. Someone else may.

 

[bholler]

It's been said on here that there's no way a 6" insulated liner fits into an 8x8, so I wasn't sure if the extra half inch would make a difference.

Copy, I'll brush the inside of the chimney with a metal brush, since it's unlined brick and looks like it hasn't been cleaned in 100 yrs (which is technically possible.)

Re: the cleanout - thank you! That sounds very doable. I'll make sure the tee cap is tightly fixed to the bottom of the tee.

The diameter of the thimble is 6.25". I haven't bought the materials yet, but I'm thinking I need to buy the insulated liner with the tee and a 10" snout, and the snout would go through the thimble. And then the stove pipe will go over the outside of the snout, up to or perhaps through the thimble.

An insulated liner will fit in there it will not fit in an 8x8 clay liner that is 8x8 outside 7" or less inside