I'm talking about the bricks on the sides next to drywall and then the big gap on top where chimeny starts to step in. I brought down the dry wall to 12 inches now so the gap isn't as big but think I still need to fill some in to create backing.

The lowered drywall now.

Remove what brick? The sides are structure part of the chimeny...

I've had inspected already. You talking about the hearth? The bricks on the sides aren't decorative.

Your local fire department is more than happy to inspect and explain about noncombustible surfaces, combustible surfaces, conductive surfaces, firebrick, and issues with extending a surface past that firebrick. They will even give you a smoke detector. Safety in design on the front end is better than them using the axe to gain entry and put out the fire.

It is clearly a gas fireplace. Probably the easiest solution is to add fire brick in the gap to level it all out and then tile directly on brick. Mortar will help level everything as well. Alternately, you can trim your drywall back to allow space to add cement board to cover the gap and the remaining brick.

You may find this helpful: https://www.thisoldhouse.com/fireplaces/21193408/tiling-over-a-brick-fireplace

Yes it has had a gas system put in. Its not ventless or anything. I'm not 100% i want to keep it gas. I just want it to be to code.

So cement board is a acceptable non combustible material?

Yes, cement board is acceptable as a surround material.

f I remember correctly, a gas fireplace can't be converted back to wood, so electric would be the only other option.

Ok thank you for that information.

I don't see why it couldn't be. In my case atleast. Everything for the the original fireplace is still there. All they did was put logs in it and a gas line. Of course gas line have to be removed. There is no insert or any extra venting installed with it.

I don't mean it can't be converted to wood, I'm saying I believe code doesn't allow it. But of course codes could be different where you live, but worth checking out before attempting it.

Yea I'm not sure. Just wonder why that is. If it gets put back to code for a wood burning chimney. Just curious od why that is.

So I demoed the hearth tile and found the bedding cracked and crumbling so removed. So my next question. It seemed they just put fore brick in and filled it all with mortar. Is this OK to repeat? Or should I lay a layer of mortar and stick them in and then mortar top? Thank you in advance for advice.

As long as it is sturdy and fireproof, should be fine.

You need to decide what FP you want that is how you make plans for install to code.

You can have gas to your wood burning fireplace. We have a gas log starter in our wood burning fireplace. (My husband is a building inspector in CA.) You have a non combustible hearth for wood burning - I think it has to be a minimum of 12 inches, but not positive of that measurement.

@Daisy S It's already gas, they are interested in changing back to wood burning.

In our location (Florida ) 12 inches is minimum distance from FP openning to mantle.