Modifying a fireplace for new insert

[bkon73]

Mod EDIT: Subject moved to it's own thread.

Moved in one year ago with an existing fireplace and caution from the previous owner not to use. Upon inspection I've discovered the chimney cap is shot, mortar between clay segments of the flu is missing, the firebox needs repointing. Started thinking of repairs when I came upon the 26% tax credit for efficient wood stove inserts. Made the decision easy, time to run a stainless flu through the clay and install the Ashford 25. I'd like to bump out the front a few inches, raise the insert 2 - 3" then add a proper hearth with correct R-value on the floor. Attached is a pic of my current situation. Thanks for your interest in helping me!

 

[bkon73]

1/2" Micore rated R1.03. 1" Stone rated R0.08. I intend to remove the tile, secure Micore, then stone, then add a piece of molding around, unless you had a better idea. Brilliant solution, thank you for posting it, I was having trouble finding the information until I came upon your post.

 

[begreen]

The buildout should be done with brick or other non-combustible. What are the dimensions of the current fireplace?

The raised hearth gets a bit more complex because of a few factors. The first is whether the fireplace lintel has to be raised if the hearth is raised.

 

[armanidog]

And you may need to attend to the chimney as well. Maybe post some pics of the chimney above the roof. Especially the top of the cap.

 

[bkon73]

The buildout should be done with brick or other non-combustible. What are the dimensions of the current fireplace?

The raised hearth gets a bit more complex because of a few factors. The first is whether the fireplace lintel has to be raised if the hearth is raised.

Current granite surround is 58x35”. The fireplace is 42-1/4 x 26” depth at bottom is 19-1/2”, depth at top is 14-1/8”. I need 23-1/2” on height for the insert. Was thinking to use glue goo and fire brick to build up the base of firebox to match height on new hearth to get them both a few inches off the floor. If I bump out a few inches with fire brick, what must I use across the top to span the long dimension? Do I make a form, mortar brick then remove the form or should I use something else as a lintel?

 

[bkon73]

Current granite surround is 58x35”. The fireplace is 42-1/4 x 26” depth at bottom is 19-1/2”, depth at top is 14-1/8”. I need 23-1/2” on height for the insert. Was thinking to use glue goo and fire brick to build up the base of firebox to match height on new hearth to get them both a few inches off the floor. If I bump out a few inches with fire brick, what must I use across the top to span the long dimension? Do I make a form, mortar brick then remove the form or should I use something else as a lintel?

Flu goo, not glue goo. Autocorrect, aargh!

 

[bkon73]

Thanks for the chimney concern. I’m already addressing this by removing the top 5 or 6 courses, relaying and replacing with a new crown. Now also considering adding the copper top I found advertised on this site. I’m so excited to get this operational to start burning again after missing all of last year. Im also super excited about the prospects of heating my home more efficiently with an insert.

 

[bkon73]

Here are pics of chimney before. Repair is now underway.

 

[stoveliker]

To start burning, do you have dry wood? As in moisture content below 20% (and in 99% of the cases NOT as in "seasoned wood for sale").

If not, your new Ashford may not (at all) do what you expect and read about it.

 

[bkon73]

Thank you for this tip. I will get a moisture meter and heed your warning Minister of Fire. Fo you have a similar stove? With properly dried wood does it perform well? I’ve always had traditional fireplaces which needed constant attention to produce heat. I’m looking forward to a more efficient wood heat experience and hope my expectations are reasonable.

 

[stoveliker]

I have a freestanding BlazeKing Chinook. Same concept/technology, different packaging. Couldn't be happier.

 

[begreen]

What is Flue Goo?
Will the lintel need to be raised to accommodate a new insert and raised hearth? If so the fireplace floor will need firebrick, but the hearth extending out in front does not need firebrick, but will need to honor the hearth requirements of the insert.

 

[bkon73]

Flue Goo is a refractory cement I used to maintain the refractories in my previous prefab Superior fireplace. Come to find out Superior has been bought and sold multiple times and replacement parts for older models were no longer available. My old refractories look like Frankenstein, but all the cracks from years of hot fires are sealed. This product dries super hard and was easy to work with.

 

[begreen]

Ah refractory cement. It sounded like an ingredient for a Chinese dish, flue goo gai pan. I don't see a need for that in this project. I think firebrick mortar is more appropriate for the fireplace floor.

 

[stoveliker]

Thank you for this tip. I will get a moisture meter and heed your warning Minister of Fire. Fo you have a similar stove? With properly dried wood does it perform well? I’ve always had traditional fireplaces which needed constant attention to produce heat. I’m looking forward to a more efficient wood heat experience and hope my expectations are reasonable.

I now have a bit more time.
Yes, with dry wood it performs really well. (I know, because I have also burned with borderline wood - which made me re-split most, stack it log-cabin style near the stove with a fan blowing every hour for 5 minutes... - luckily my stove is in the basement).
It will burn more sluggishly when wood is wetter. And you risk creating more creosote.

The "constant attention" is not needed here; that is the benefit of a thermostat. After initial start up (of the load of wood), you'll have to deal with closing the bypass valve. But once you know what the right thermostat setting is for the weather (outside temp affects draft, the colder the more draft), heating needs/comfort level, wood you have (type and dryness) - and yes, this will take at least a whole season of playing, ahem, learning - , you can really set it and forget it. I'm not saying that is not possible with other (types) of stoves (experienced burners will be able to do very similar things), but the Blaze King technology makes it easy.

The burn times advertised for the model do work out for me. I have a larger firebox (30.2 model), and they advertise 30 hrs with that on low. In my very first try I reached (if I'm remembering correctly) 26 hours.

Now, on low it puts out less heat, after all, you're stretching out the fuel crammed in the firebox over a longer time. So when it gets colder, don't count on the maximum times. I ran on 12 (often 14..., which is a nuisance) hour reload cycles then.
Also, on low you won't see flames. So if you want the ambiance of a flame show, you'll be running higher - which will decrease the burn time. (But again, I ran near half the advertised times when I ran 3/4 open in the coldest days.)

Regardless of this particular stove technology, any stove will be more efficient than a fireplace. And any modern EPA stove will be more efficient than a pre-EPA stove. You'll be amazed what the technology developed by the manufacturers is able to do.

Do read the manual, and follow it "to the letter", at least in your first fires. Take care of our catalyst/combustor.

Above all, have fun, warmth, and switch off your tv - no need for that when you have a fire

 

[bkon73]

Would much rather curl up by the fire than yhe TV any day. Your thoughtful recap is much appreciated. This is a similar recount to that shared by the company selling me the stove, but it is always more comforting to hear it from someone who is walking the walk. Based on your comments I think a future project entails an outdoor cemrnt pad and a woodshed. It may take me a season or two to get rolling properly, but I’m up for the task! Thanks for your time and commentary.

 

[stoveliker]

There is a thread "show me your woodshed". Have a look, get ideas. This spring I built a shed (well, a roof above a floor on deck blocks) with three bays, so I can do a three year seasoning cycle.

Getting ahead (collect, split, stack) enough wood to get ahead is some work, as you'll be doing wood to be used 2 (or better, 3) years, but after that it's only resupplying what you burn in one year.