So gang, what's the final word on heat transfer through screw in a hearth?

[Planeweird]

I'm putting 1/2 micore over wood sub-floor, 1/2 durock over that, and capping it all off with extra thick quarry tile.

I was planning on using 2" screws through the durock into the micore and finally into the sub-floor and then thinset and tile. Acceptable?

Or do I need to screw down the micore, thinset the durock onto the micore and then thinset the drock on top of that?

Or do I need to do a combination of both?

Tackling the hearth, liner, and stove install this week. I will post pics

 

[Highbeam]

I don't buy the whole heat transfer through screw theory, especially when you will be tiling on top of it all. I would firmly attach each layer independently which means screw each layer which looks like your second option. The temps that occur under the stove are just not that hot and since the screws are seperated by many inches, the heat from a single screw can be dispersed.

 

[Planeweird]

Highbeam,

I'm with you on that line of thinking, but I thought I would throw it out there and see if anyone knows something I haven't considered(which is fairly normal).

 

[BrotherBart]

Better to ask beforehand than to have to tear out a lot of nice work.

 

[Planeweird]

Better to ask beforehand than to have to tear out a lot of nice work.

Indeed Especially when I'm winging it on most things. Figure if I ask the right questions and think it through, I'll usually be ok......hopefully.

 

[begreen]

I don't think the micore has enough body to screw down on its own. And certainly not enough to anchor the durock top layer. Screwing the micore down in a sandwich with the durock top layer seems to be the way I would do it. I agree with Highbeam, the heat transmission, diffused by the quarry tile is likely to be minor by the time the thread hits the sub-floor.

 

[Wet1]

I've never worked with micore, but could you bond everything together with thinset?

 

[jlow]

I used micor then fiberock and then I laid my brick. City inspector had no problem approving it for code purposes. I did use thin set to adhere micor to plywood as it is
not a hard substance. I screwed the fiberock through the micor to adhere both to plywood. Used thinset again to adhere brick to fiberock. The heat geneated from my equinox at full burn left the brick slightly warm to the touch.

http://picasaweb.google.com/jlowry10/HearthPad#

 

[hibeam]

Can you even buy those special durok screws long enough to get this job done. You want to use those fancy durok screws so that they don't corrode and so that they countersink right.