Question about renovating a wood fireplace hearth

[Sydmax]

We are currently in the midst of a first floor renovation. We have in our family room a floor to ceiling brick veneer wood fireplace similar to the one in this picture (to give you an idea of what it looks like):



We have discussed various ideas as my wife hates the thing. One thought was attach a piece of granite that she liked to the top of the brick on the hearth and then trim out the sides. However, the hearth extension sits flat to the opening of the firebox. Therefore, if you laid a 3/4 to 1 inch granite piece on top of the brick, the hearth extension is now that much higher than the firebox opening and I don't believe we'd be able to then put back the glass doors we currently have there and would like to reuse. I don't know it's even allowed to now have the hearth extension almost an inch higher than the firebox opening.

The other option is to just remove the brick hearth extension. But then you run into questions of rebuilding the hearth and what kind of materials would work (R-value). Could you use wood stud framing with a few layers of cement board attached followed by the granite (or cement slab or tile) on top to achieve the right values?

Any guidance would be appreciated. FWIW, the home is located in South Jersey and there is a basement below as this fireplace is on the first floor.

 

[Simonkenton]

My fireplace at left is built with the hearth setting 2 inches above the floor of the firebox. I deliberately built it this way, it helps contain the ashes in the firebox. So you could certainly raise your hearth an inch.
However then your glass doors wouldn't fit. Maybe you could cut an inch off the bottom of the doors.
Yes I don't see why you couldn't demo the hearth and rebuild it. Wood framing with an inch of cement board topped with tile or granite sounds good to me.

I gotta agree with your wife, that is one ugly fireplace. Good luck!

 

[kennyp2339]

Hmmm, I would be very leery on installing 3/4" to 1" granite over the whole hearth and wall until you make sure the floor can support the extra weight.

 

[Sydmax]

Hmmm, I would be very leery on installing 3/4" to 1" granite over the whole hearth and wall until you make sure the floor can support the extra weight.

Didn't think of that. Given the weight of the bricks already on the floor, adding a big slab of granite might be too much.

 

[Sydmax]

Sorry, one more question. I know that if a new hearth is built, it should not touch the face of the fireplace, leaving a 1/8" gap.

But does that just apply to the wood base and that I can butt the tile or granite top up and other non combustibles up against the fireplace?

Thanks again for any guidance.

 

[Simonkenton]

Is it a finished basement? If not it would be a simple matter to reinforce the floor joists beneath the hearth. Run a 4x4 beam across the joists, then put a 4x4 post under that beam.

 

[Sydmax]

Is it a finished basement? If not it would be a simple matter to reinforce the floor joists beneath the hearth. Run a 4x4 beam across the joists, then put a 4x4 post under that beam.

Finished. So this probably wouldn't work.

We may end up even just removing the brick above the mantel (and I said brick veneer but what I meant was actual brick but is not structural to the fireplace), drywall that and then paint the brick around the firebox opening and the hearth extension and maybe add some trim, etc.

 

[bholler]

Hmmm, I would be very leery on installing 3/4" to 1" granite over the whole hearth and wall until you make sure the floor can support the extra weight.

If it was built properly there should be no problem supporting the weight that extension should be on top of a slab that was poured as a part of the hearth slab. But many are not built that way. But really i doubt that amount of weight would be an issue regardless.

 

[bholler]

Didn't think of that. Given the weight of the bricks already on the floor, adding a big slab of granite might be too much.

Is there a crack between the hearth extension and the hearth now? That is usually a good indicator that the extension was just built on top of the floor and not on the slab like it should be

 

[Sydmax]

Is there a crack between the hearth extension and the hearth now? That is usually a good indicator that the extension was just built on top of the floor and not on the slab like it should be

There is no crack but it's hard to tell. There is a wall of regular brick that appears to be decorative like in the picture in the first post. The hearth extension is also brick attached to the wall of brick. When I look inside the firebox, I can see that the brick veneer (for lack of a better term) is up against the face of the fireplace.

Also, it does appear there is a concrete pad. Our basement is finished but there is a drop ceiling and I looked and there are some plywood panels nailed at a 45 degree angle between the joists right under where the hearth extension would be and there appears to be concrete behind those panels, if that makes sense.

If I get a chance, I'll upload some pictures. I also may just have a masonry inspector or engineer come in before we would do anything to it.

 

[bholler]

If I get a chance, I'll upload some pictures. I also may just have a masonry inspector or engineer come in before we would do anything to it.

Just a sweep should be fine. If there are forms under the hearth extension then it has a slab under it and you will be fine. But those wood forms should not be there. They should have been removed after the slab was poured.

 

[Sydmax]

Just a sweep should be fine. If there are forms under the hearth extension then it has a slab under it and you will be fine. But those wood forms should not be there. They should have been removed after the slab was poured.

Yeah, they are still there but not much I can do now as they would be tough to get to.

 

[bholler]

Yeah, they are still there but not much I can do now as they would be tough to get to.

Not really we remove them all the time. And with a drop ceiling it would not be a big deal

 

[Sydmax]

Just a few photos.......... first is the connection between the wall and hearth extension, second is what I think is the pad, third is the inside of the firebox where there interior brick decorative wall meets the firebox.

To get out the forms, just basically pound them out?

 

[Simonkenton]

You have a 45 degree "slab" poured in the basement ceiling to support that hearth. That is commonly done, that makes the hearth setting on a solid concrete foundation. You are good to go, very good support for that hearth.

 

[Sydmax]

Glad to know they did it right when they built the house!

So it looks like have options now............. I can tile or use granite on top of the existing brick extension or just rip the extension out as well right along that vertical mortar line between the extension and the wall of brick (the one plan is to remove the upper half of that brick wall and drywall it or panel it and then leave the bottom half).

Thanks guys.