Ideal Steel Hearth question?

[NVHunter]

Ok, gonna take on a remodel and want to install an Ideal Steel.

The hearth requirements for the ideal steel is an r value of 0.41.

Would 2 layers of 1/2" Duroc (0.26 r value each) plus 3/4" slate tile meet the requirements?

When stacking material you just add the r values to get the final number correct?

The hearth will be built like this:
Framing: 2x10"
Next: 3/4" ply wood.
Next: 2, 1/2" sheets of Duroc for 1" total
Next: tinset mortar with 3/4" slate tile on top of hearth.

Should come out to about 0.6 r value with the Duroc and slate tile.

Does this sound acceptible?

Thanks

 

[pen]

0.26 + 0.26 = 0.52 which means that there meets/exceeds the required 0.41. The slate and thinset doesn't add much, but that's above and beyond if 0.41 is all that is required.

 

[Grisu]

Does this sound acceptible?

It does but if you need to have some kind of inspection done I would run it by them. You don't want to put the work in and then they tell you it is not enough (for whatever reason).

 

[begreen]

Durock NexGen is all you can buy now. It has an R rating of .39 / .5in. It sounds like you would be ok with just a single sheet and the slate. But your plan is fine if you want to add a second layer for peace of mind. There is no harm with more protection.

 

[NVHunter]

Thanks for the replies everyone.