Building and Raising Hearth Extension help please

[swanderek]

Well hello gain,
After having a few shops come out and give bids, my wife and I decided that a wood stove would just take up too much room. Now we have our eyes on the Regency Hearth Heater. (Literally the only insert that will fit.)

Now my questions is this: My fireplace is raised up about 6.5 inches from the floor. My current hearth is just flat tile. To get the hearth heater to work I have to raise my hearth up to be flush with the fireplace. (I do not want to use the front legs option. What's an easy way to raise the hearth up enough for the hearth heather to sit on it?

I was thinking about a basic box with double 2X4 with a layer of plywood, layer of cement backer, then tile on the top.

 

[begreen]

The insert will need more thermal protection than just cement board and tile unless the insert is raised at least 3.5" above the hearth. If it is flush the hearth needs to have at least R=1.1 insulation. There are several ways to accomplish this requirement including building up the hearth with masonry, heavy steel studs, or conventional wood stud framing, but with adequate insulation on top. For example, 3 layers of Durock NexGen would achieve and R= 1.17 rating.

See page 9 of the manual for the requirements.

 

[bholler]

What type of fireplace is this? If it is a traditional masonry fireplace a permanent hearth extension needs to be built to code for an open fireplace which means no combustibles at all below it. It needs to be built on a slab tied to the slab under the fireplace and no combustibles touching the underside of that slab

 

[swanderek]

Prefab fireplace

 

[bholler]

Prefab fireplace

Then you need to follow the instructions for both the fireplace and the stove.

 

[swanderek]

Regency said I need 1.5 inches of non comb. Material.
Would a 4 inch thick cement cinder block and 1 inch a cement board and 1 inch hearth stone be enough r value you think? I really sincerely appreciate everyone’s help!

 

[begreen]

Regency said I need 1.5 inches of non comb. Material.
Would a 4 inch thick cement cinder block and 1 inch a cement board and 1 inch hearth stone be enough r value you think? I really sincerely appreciate everyone’s help!

That would be entirely non-combustible, but without much insulation value. Concrete is R=.095/inch, flagstone is .079/inch.

 

[Ctwoodtick]

What type of fireplace is this? If it is a traditional masonry fireplace a permanent hearth extension needs to be built to code for an open fireplace which means no combustibles at all below it. It needs to be built on a slab tied to the slab under the fireplace and no combustibles touching the underside of that slab

Can combustibles be touching the sides of slab underneath, such as floor joists?

 

[swanderek]

Here is what I am thinking:
4 inch cinder blocks on bottom- .4 R
1 inch of the durock next gen -.78 r
1 inch of hearthstone- .08r

Total of 1.2 r rating

Does that sound legit?

Any insights to building this or getting the h2100 would be great.
Going into prefab fireplace and right now the hearth is floor level and needs to be raised 6 inches to make the fireplace and insert flush.

 

[bholler]

Can combustibles be touching the sides of slab underneath, such as floor joists?

The sides yes as long as they are past the noncombustible range

 

[bholler]

Here is what I am thinking:
4 inch cinder blocks on bottom- .4 R
1 inch of the durock next gen -.78 r
1 inch of hearthstone- .08r

Total of 1.2 r rating

Does that sound legit?

Any insights to building this or getting the h2100 would be great.
Going into prefab fireplace and right now the hearth is floor level and needs to be raised 6 inches to make the fireplace and insert flush.

Before you go any further make sure you can meet the required clearances to combustibles from the stove to the framing around your fireplace. You also need to make sure that fireplace and chimney are in good condition and were installed correctly to start with

 

[swanderek]

Any problems with putting manufactured hearth stone on top for the 2100 hearth heater to sit on or does it not the be “real” stone?

 

[begreen]

What is the product? If it's manufactured from concrete, no problem. If it is resin based, problem.

 

[swanderek]

After looking around at Lowe’s and homedepot online it looks like their manufactured stone gets mixed reviews. Is there another option you guys use to find 2 inch thick hearth stone?

 

[begreen]

http://www.mutualmaterials.com/branches/tacoma-parkland-wa/

 

[swanderek]

Wow that’s close thanks!!
Begreen do you live in Washington?