Raised hearth edges and moulding

[skarybat]

Hello!

I’m about to build a raised hearth extension for my existing hearth. See the drawing attached. I tried to respect the Canadian code in regard to distance from the door of the insert and heat insulation.

My question is: are there any restrictions about the material used on the side of the raised hearth ? Can the sides be made of wood? Can I use wood moulding around the tiles on the top of the hearth ?

Thank you so much for your advice!!

 

[begreen]

Possible, as long as it is the required distance away from the stove to honor clearance requirements. Why the high R-value hearth extension? Is this a requirement of the insert? It would be better if the layer under the tile is cement board. Micore is not a good tile foundation, it is porous and fibrous.

 

[skarybat]

Possible, as long as it is the required distance away from the stove to honor clearance requirements. Why the high R-value hearth extension? Is this a requirement of the insert? It would be better if the layer under the tile is cement board. Micore is not a good tile foundation, it is porous and fibrous.

Yes, the requirement of the insert is R value of 2, that’s the reason for using Micore. The installer told me to use it in order to have my WETT certification. I thought it was sold enough for tiles. Should I cover it with cement board?

 

[begreen]

Yes, cement board is recommended. That's a fairly high R value. It's good that you are trying to do it right.

I thought that the Canadian requirement is 18" in front of the stove door. The drawing makes it look like it's from the front of the blower.

 

[skarybat]

Yes, cement board is recommended. That's a fairly high R value. It's good that you are trying to do it right.

I thought that the Canadian requirement is 18" in front of the stove door. The drawing makes it look like it's from the front of the blower.

You’re right, it’s 18 inch from the front door. I’m still not decided on the exact depth of the extension I will build. I thought I would extend it a little more because I want the added part to be stable on the floor. I feel it would be wobbly if the added part was only 3-4 inch deep.

 

[begreen]

What is the current hearth material in front of the fireplace? Can you post a picture?

I'm just wondering if there is an alternative. What insert is this for?

 

[skarybat]

What is the current hearth material in front of the fireplace? Can you post a picture?

I'm just wondering if there is an alternative. What insert is this for?

Yep, here is a picture of the fireplace as it is right now. The hearth is made of poured concrete. The insert will be Regency i1500.

I really appreciate your input.

 

[begreen]

This looks like a new insert model. The hearth specs say:
*Floor Protection Thermal insulation/protection with a R value of 1.4 at a distance of 18" from door opening is required for Canada and 16" for USA. If unit raised minimum 4.5" from hearth, no thermal protection is required.

Note the hearth requirement is R = 1.4. That is easier to achieve if required for the extension. However, I am wondering if the second part could be interpreted to mean that the hearth extension could be at floor level with ember protection only. That's not uncommon. If so, a simple 4-6" strip of metal there could suffice. It's worth a call to Regency support to check out.

 

[skarybat]

This looks like a new insert model. The hearth specs say:
*Floor Protection Thermal insulation/protection with a R value of 1.4 at a distance of 18" from door opening is required for Canada and 16" for USA. If unit raised minimum 4.5" from hearth, no thermal protection is required.

Note the hearth requirement is R = 1.4. That is easier to achieve if required for the extension. However, I am wondering if the second part could be interpreted to mean that the hearth extension could be at floor level with ember protection only. That's not uncommon. If so, a simple 4-6" strip of metal there could suffice. It's worth a call to Regency support to check out.

 

[skarybat]

Yes, it's just released. It's the new version of the i1200, on which they put a catalyst combustor. In theory, maybe I could just raise the insert and therefore don't need the extension. However, I like the look of it and I'm not quite sure the fireplace is high enough to allow that.

1.4 R is good news. It's less than I expected, but I still need to insulate the existing concrete, since it takes 8 inch of concrete to get to 1.4, if I get it right.

My plan is to stick with the original plan, but I will add a 1/2 cement board on top of Micore 300. This will get me to a fireplace opening of 21 inch high, still enough to fit the insert. It will be tight, but the saler assures me there is no problem since the i1500 requires 19 inch opening.

 

[skarybat]

Here is the updated drawing thanks to your advice regarding tiles on top of Micore.

I have one last concern. Now with the tiles, micore and cement board, the hearth extension will be about 2 inch higher thanks the bottom of the fireplace opening. Will it be easy to shim the insert so it is flush with the top of the hearth?

 

[begreen]

Yes, it's just released. It's the new version of the i1200, on which they put a catalyst combustor. In theory, maybe I could just raise the insert and therefore don't need the extension. However, I like the look of it and I'm not quite sure the fireplace is high enough to allow that.

1.4 R is good news. It's less than I expected, but I still need to insulate the existing concrete, since it takes 8 inch of concrete to get to 1.4, if I get it right.

My plan is to stick with the original plan, but I will add a 1/2 cement board on top of Micore 300. This will get me to a fireplace opening of 21 inch high, still enough to fit the insert. It will be tight, but the saler assures me there is no problem since the i1500 requires 19 inch opening.

Are you saying the concrete hearth stops at floor level? Or does it continue on down below the floor? It should.

To reach the R=1.4 requirement only the 1 sheet of micore is necessary.

 

[skarybat]

Yes, the concrete hearth extension sits on the sub floor, not the wood flooring. I will trim the wood floor to build the added hearth part.

 

[begreen]

Hmm, that does not sound like a proper hearth.

 

[skarybat]

You’re right. It doesn’t sit on the subfloor. I just checked with the seller. The hearth goes through the floor and is attached to the chimney. It’s correct.

 

[begreen]

Good, that's much better. I would call or email Regency support and describe the hearth. Ask if the hearth extension can be ember protection only. If so you could set the extension into floor so that it is flush.

 

[skarybat]

The seller will check if just ember protection is needed. If it's allowed, he suggested maybe a couple of slabs that could overhang 3,5 inch in front to meet the 18 Inch requirement from the door opening. That would be much more simple.

 

[skarybat]

So here is the beginning of the transformation. I’m still waiting for the Micore to be delivered to my place. I will put 2 layers of Micore on the wood frame, then one cement board over the whole thing and finally tiles. I’ll show the final result shortly.

 

[skarybat]

Here is it! I’m now waiting for the insert.

 

[begreen]

It looks great. A little planning goes a long way.