Demolition - need some advice...

[Creek-Chub]

Fellas,

I asked some basic questions about this last year, but never ended up following through with the plan. The time has come for me to either put up, or pay up. I have what I had at one time thought was a "masonry fireplace", but which is actually some sort of a "heatform" unitl within a masonry fireplace. Some photos to give you an idea:

I have attached photos of the front of the fireplace, then the problem hearth, and where the "heatform" used to meet the bottom of the hearth: I have more and better pictures, but was trying to keep the quality low enough to meet the max 350K attachments limit.

Here is my problem:

I wanted to fit a "hearth" type stove into my fireplace opening. Depth and width weren't a problem, but I only had 24" of height to play with, and 2500SF to heat, and it just wasn't happening. I began to dismantle the hearth so as to drop the level and gain more height. I removed a solid hearth pad (some sort of stone), a row of firebricks, and now I'm down to a poured pad. The pad was poured with re-bar running N/S and E/W, on top of a sheet of 1/2" plywood, which is on top of concrete blocks, which continue on down through the floor into the crawl space and end on top of a concrete footing.

I want to remove the portion of the concrete pad that is inside and in front of the fireplace, but to be honest I don't want the whole thing to come crumbling down. What say ye? Can I go to town on the pad with a sledge hammer and a sawzall? Can I safely take this out at all? Do you have any other suggestions? I already purchased a 30-NC, so come hell or high water I plan to jam it in there. I need to run a couple of rows of time around the front and sides of the fireplace so as to meet minimum clearances, but want to get the hearth situation taken care of first. I'm sure I've missed plenty of pertinent information, so if there is anything important I have left out, feel free to ask. I plan to try and get a couple hearth guys out to take a look at it this week, but they always seem to be hit or miss - and I figured you fellas had probably seen just about everything. Thanks in advance.

Edit:

In a perfect world I would like to take out all of the hearth all the way down to the floor, but I at least need to get rid of the concrete pad. My only concern with busting it out all the way to the floor would be inviting structural problems. Am I off base?

 

[KeithO]

Will you be able to meet the required hearth extension in front of whatever you intend to put in there when your done ? Times and codes change and you may find that you need several inches more floor protection than you have now. 16-18" in front of the loading door seems to be the norm. Have you looked at the Blaze King inserts ? They are pretty big for your square footage.

 

[Creek-Chub]

Yes on room for the hearth extension. I'm going to run two rows of 12x12" tile in front of the hearth and around the sides. The chair will be moving, and the furniture in general will be backing up. The room is 25'x25', so I've got plenty of space to shuffle things around.

I checked out the blaze king, but decided to just buy a free-standing stove. I've got an Englander 30-NC that I just picked up.

 

[wellbuilt home]

Hay creek you cant remove the cement from under the steal fire box . The steal is there to forum the smoke chamber and hold up the block until the cement drys.The problem is really with the clay flue . The flue sits on the box ,if the steel box drops, all the flues could come down . I think i would put the sledge hammer back in the garage and go rent a hilti chipping hammer then chip holes in the corners of the fire box about 4"x4" and fill them with a Portland cement sand mix and let it dry for a few days . Then chip out the rest of the old concrete and fill the hole with the same mix . Some old fire box's were thin steal and some box's had a double wall siting on the slab I cant tell witch you have . I have removed lots of the old boxs . We would drill a hole in the chimney and slip a 1/2" steal rod in the hole to hold up the flue. This is not a DIY type of job. Most stoves come with short legs Ive even cut some legs.

 

[Creek-Chub]

Here is what it looks like where the heatform unit "meets" the hearth. There was firebrick between the slab and the steel walls, but it slid right out. Definitely no weight on it. I'm actually curious as to what is supporting the steel insert. Does this change your thoughts at all?

 

[Creek-Chub]

bump for the evening to see if anyone else cares to chime in. I know I need to have a mason/sweep out to look at it, but was hoping to sound somewhat intelligent when I do...