Renovating Builder Grade Fireplace

[B34N]

The time has come to remodel our family room and the first thing we need to improve is the builder grade masonry fireplace. Our goal is to create a single main focal point of the fireplace wall, instead of our current setup which has a second focal point of the TV mounted on an adjoining wall.

Objectives:
Fix/replace cracked hearth
Reduce draftiness
Install TV above mantle at a comfortable height

Current Plan:
Totally renovate, hearth, surrounds and mantel
Install a gas insert

Our understanding is that if we move to a gas insert that we could potentially lower the mantel height by as much as 20" from where it is today. We probably wouldn't go that far, but a lower height will certainly help with the TV viewing angle.

Question:
What should we expect to find behind the granite of the raised hearth extension? Would it be hollow? Cinder blocks? Concrete?

Our thought is that just lowering a mantle would look really weird. While we cannot (easily) lower the fireplace opening since it's masonry, we thought that replacing the raised hearth with one level to the floor would help keep proportions for the mantle in better balance. This would leave us with a fireplace "floating" 11" above the floor. From photos we've seen, we feel we can design the surrounds and mantle in a way where if wouldn't look weird.

Are there some other factors that we need to consider? Have any of you done or seen a similar renovation?

Some measurements:
Fireplace front opening width: 41 3/4”
Fireplace front opening height: 33”
Width at the back of fireplace: 21 1/2”
Fireplace depth: 20-1/4”
Width of hearth: 68”
Height of hearth extension: 11"
Depth of hearth extension: 19-1/2”


Thank you,
B34N

 

[DAKSY]

I have replaced MANY of these ZC wood burning units & replaced them with either ZC EPA-Rated
wood burners or gas fireplaces.
Your hearth riser is probably framed with 2x lumber & there should be micore under the hearthstone.
I would forget about an insert. It may be too small for your taste & may not even be allowed in your ZC Wood burner.
The process for a two-man crew & the first day of work:
The entire mantel, surround, riser, unit & venting is removed.
The opening is plumbed (if necessary - for gas), reframed, sheetrocked & insulated & the new unit (& venting) is installed.
The new installation can be set at whatever height you desire.
The interior wall sheet rock is installed & taped. This will take return trips.
The hearth stone, facing & the mantel are installed.

 

[B34N]

I have replaced MANY of these ZC wood burning units & replaced them with either ZC EPA-Rated
wood burners or gas fireplaces.

Thank you for replying! Why do you say this is a ZC? I'm pretty sure it's masonry. We have an ash dump (I prefer to call and ash hole for fun) and the chimney is solid brick.

Your hearth riser is probably framed with 2x lumber & there should be micore under the hearthstone.

I like your answer. I should have attached this photo of the fireplace from the basement looking up. It looks like the poured concrete comes out quite a bit from the exterior wall so I was concerned.

I would forget about an insert. It may be too small for your taste & may not even be allowed in your ZC Wood burner.

If I am correct that this is a masonry fireplace, does that change anything? I will look into the sizing more. It's hard to tell when going from the fireplace store to home. Thanks for the tip.

The process for a two-man crew & the first day of work:
The entire mantel, surround, riser, unit & venting is removed.
The opening is plumbed (if necessary - for gas), reframed, sheetrocked & insulated & the new unit (& venting) is installed.
The new installation can be set at whatever height you desire.
The interior wall sheet rock is installed & taped. This will take return trips.
The hearth stone, facing & the mantel are installed.

I really appreciate this process description. Thank you.

B34N

 

[DAKSY]

Ok, my bad. My description was for ZC box removal, not masonry.
It LOOKED like a ZC box from the first pic & the stone surround.
If that's the case, & the original construction was brick, then the hearth riser
is probably masonry as well, & you won't know what's under there until you start destructing it.
When you go to a hearth shop, take the first pic with you.
Also, take the measurements of the fire box with you.
If you can take a pic of the outside, showing the Ground & the ENTIRE chimney, take that as well.
You can't have too much info when you're shopping.

 

[begreen]

The hearth construction details are unknown. It is going to take some exploratory surgery to find out what is there. Hopefully it is masonry underneath.