Can cement board be re-used?

[Partridge4]

Greetings from Vermont. I have been reading these forums since January and am now ready to have our Hearthstone Heritage installed in front of our existing brick fireplace, in our 1965 home. The hearth is flush, but needs a 1.2 r-value. I pulled up the corner 1/4" slate tile to find 1/2" cement board over the plywood. I would like to remove the cement board, put 1/2" Micore down (we are blessed to have a local dealer in our town!) and wondered if I could re-use the cement board over top, or if I should replace it with new. Either way, that will mean that with 1/4" tile, I will have a 1/2" - 3/4" rise above the wood floor. So my questions are: Can the cement board be reused (then I don't have to deal with trying to cut a new piece to fit into recess over micore)??? And if not, could we use 1/4" cement board over the micore, which will make it flush with wood floor, then only a 1/4" rise when tile is installed? Or, should we use new 1/2" cement board so we don't run into rigidity issues for the new 1/4" ceramic tiles? I have read that 1/4" cement board has a .1 r-value, so that will meet requirement.

I apologize for all the newbie questions, but if I ever want to sleep soundly with the woodstove going, I just have to know my options for our specific situation We live in a very wooded setting (free wood!) and want to significantly reduce our heating bill. Thank you in advance! If I have missed a thread that covers these specifics, please let me know!

 

[fossil]

It's standard practice to use a Durock substrate beneath ceramic tile, so it's no surprise to find it there. If the surface and structure of the Durock is sound after you get all the tile up off of it, there's no reason it can't remain in place. The remaining thinset can be smoothed with careful use of a belt sander...but be gentle, because you want to minimize damage to the fiberglas mesh that's in the surface of the Durock. I imagine that there's a layer of thinset between the Durock and the subfloor, as well as a whole lot of screws, so removing the Durock entirely would really be a job. Rick

EDIT: I just re-read your post, and now it seems to me your question is can the existing Durock be removed, then reinstalled over the top of the new Micore. The answer to that is probably not...I think you'll do a lot of damage to it getting it out of there.

 

[JPapiPE]

Cement is Cement is Cement,,,yes you can use it again if you haven't put divits into it by removing old tile

 

[Partridge4]

Thank you ... maybe it should be common sense but I don't want to take any chances with an older home. I will pull up the old slate tiles and see how it's all buckled down, and proceed from there. Would you agree that I should use 1/2" cementboard over the micore rather than 1/4"? I haven't purchased it yet, but have read people's concerns about its texture.

 

[fossil]

I've never worked with Micore, but my understanding is that it's a terrific insulator & a not-so-terrific structural material. If you can figure out a way to use 1/2" Durock over the Micore, that would make more sense structurally. Rick