Zero Clearance Hearth Pedestal Materials.

[AlaskaNorth]

I am tearing out my pre fab in preparation for a new Zero Clearance. The existing Hearth pedestal was block covered in brick. I want to extend the pedestal to the right and left as well. I was hoping to be able to frame it out with wood and cover with veneer (face) slate, stone, or tile on top. Is this acceptable? Is there a tile or covering material that could reach an R value of 2.0 which the manual states?



What I am trying to determine this very moment is if I should leave the block in place as is for now. I was starting to remove it thinking I'd just build a frame, then it hit me that may not be ok with what I want to do. I want to keep the height and depth, but am replacing the old brick with modern materials. What options do I have for the hearth extension?

Manual for the unit I purchased below. Page 40 for required clearances and R values.

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://sbiweb.blob.core.windows.net/media/3911/45858a_2021-10-27.pdf

 

[stoveliker]

Your thinking is correct: tile on wood framing won't be ok if you need R=2; it needs some insulation to reach the R value (stone, tile, brick don't insulate very well).

I'm not familiar enough with covers (as I'm more used to freestanding hearth pads).

 

[begreen]

R=2.0 is a fairly stiff insulation requirement. The underlayment for the hearth tile will need a high insulation value or a continuation of the current hearth construction. 12" of cement is a substantial heat barrier. The hearth sides could be framed if that is desired as long as the hearth in front of the fireplace meets the width, depth and insulation value required for the new fireplace.

I see this is for the Waterloo. If you want to keep the current height of the fireplace and the raised hearth in front, then consider keeping the current hearth structure. That will easily meet requirements. You can wrap it with stone or tile to hide the brick. If side extensions are desired, then can be conventionally framed. If you want to start from scratch then the new hearth will need an inch of Micore underneath the cement board achieve the R=2.0 value

 

[AlaskaNorth]

R=2.0 is a fairly stiff insulation requirement. The underlayment for the hearth tile will need a high insulation value or a continuation of the current hearth construction. 12" of cement is a substantial heat barrier. The hearth sides could be framed if that is desired as long as the hearth in front of the fireplace meets the width, depth and insulation value required for the new fireplace.

I see this is for the Waterloo. If you want to keep the current height of the fireplace and the raised hearth in front, then consider keeping the current hearth structure. That will easily meet requirements. You can wrap it with stone or tile to hide the brick. If side extensions are desired, then can be conventionally framed. If you want to start from scratch then the new hearth will need an inch of Micore underneath the cement board achieve the R=2.0 value

Thank you. yes we're keeping the height. I think I'll try to source some fiber board that meets that 2.0. R!