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Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by mepellet, Apr 24, 2013.

  1. begreen

    begreen Mooderator Staff Member

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    Argh, we've gone round on this many times. NexGen has perlite pellets. It was confused by some with their shower floor material which had the styrofoam pellets. Unfortunately it sounds like some folks at USG don't read their own product data.

    http://www.hearth.com/talk/threads/original-type-durock.69074/#post-868793

    Also note greythorn's as hoc test that follows in the thread.

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  2. Don2222

    Don2222 Minister of Fire

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  3. mepellet

    mepellet Minister of Fire

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    I noticed that. Hency my confusion...
  4. begreen

    begreen Mooderator Staff Member

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    Sorry. It would be so much easier if USG would just get this product tested and certified. That would eliminate a lot of confusion. Unfortunately I don't think the hearth.com membership is going to be able to do prod them hard enough. It will take a serious request by a large organization such as HPBA to accomplish this. It would be great if HPBA could take a leadership role here and pursue this course of action.
  5. Jags

    Jags Moderate Moderator Staff Member

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    Sorry, it was mis-speak on my behalf about the foam - yes, perlite is what is used in the Nexgen. The product hasn't been certified for hearth use. That is why I keep calling, hoping that they found a need/want to certify it.
  6. mepellet

    mepellet Minister of Fire

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    So does everyone use wonderboard then?
  7. Jags

    Jags Moderate Moderator Staff Member

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    Durock is probably the most widely used - even without the certification. Wonderboard went to a "lite" version as well and I don't know what is used in that board.
  8. Jags

    Jags Moderate Moderator Staff Member

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    Wonderboard lite

    Ingredients:

    Portland cement
    Silica, crystalline, quartz Calcium carbonate Fiberglass
  9. mepellet

    mepellet Minister of Fire

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    Doesn't make it right. I want to install this hearth to meet or exceed code. If it doesn't have the certification, it probably doesn't meet code. Most building materials need to be listed or approved for their installed use.
  10. Jags

    Jags Moderate Moderator Staff Member

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    I understand your position and that is why I keep dialing USG -hoping they would get off their butts and get this product certified. The ingredient list indicates nothing that would fail the certification.
  11. begreen

    begreen Mooderator Staff Member

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    I have seen Durock NextGen used in commercial hearth pads. Ask companies like Yoder where they are getting said certification. My guess is they are paying for the UL testing independently.
  12. mepellet

    mepellet Minister of Fire

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    I sent a request to wonderbord to see if their product is approved for my intended use.
  13. mepellet

    mepellet Minister of Fire

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    So since I am not buying a commercial hearth pad, it doesn't sound like the durock products will meet code in my situation. Why is it so hard to find a product that is approved for this use? Makes you wonder about all of the installations that are using Durock NextGen...... hmmmmmm?
  14. begreen

    begreen Mooderator Staff Member

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    Both USG and Wonderboard neglected to update their product certifications when they switched to the NexGen , Lite products. Not sure why. Either one used to be the defacto standard. They have definitely thrown confusion into the hearth industry. It doesn't make a lot of sense when the new products have a superior R value and are entirely non-combustible.
    Jags likes this.
  15. raybonz

    raybonz Minister of Fire

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    I built my hearth with Nexgen and passed inspection.. Nexgen has much better R-value than the original cement board and it is NOT combustible.. You can't light this stuff with a blow torch!

    Ray
  16. mepellet

    mepellet Minister of Fire

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    I realize that durock would WORK just fine but I also want to make sure everything about my hearth installation is to code. Just because something passes inspection doesn't mean that it was done to code.
  17. raybonz

    raybonz Minister of Fire

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    I suggest you visit the building inspector which I did before building. They asked for details of the build then checked that I did what I said I would do..

    Ray
  18. mepellet

    mepellet Minister of Fire

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    No inspection required here. But I could visit them anyway. My guess is that they won't know any more about it than anyone here.
  19. firefighterjake

    firefighterjake Minister of Fire

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    Depends on the inspector . . . and where you are located . . . some inspectors may know nothing, some may be relying on old info they learned from the dawn of time (i.e. don't be surprised if one tells you there has to be a 3 foot clearance from the stove to the wall and some folks actually take the time to learn -- rumor has it that some actually even hang out here at hearth.com.

    Personally, if I was the Inspector I would most likely give the green light to the NextGen Durock even without the hearth endorsement . . . sometimes a bit of commonsense has to come into play and as noted . . . there is nothing in it that would give me a real concern and if anything it seems a bit better . . . for me the real key would be watching the R value requirement for the hearth/stove match up and the clearances.
    raybonz likes this.
  20. tfdchief

    tfdchief Minister of Fire

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    ;)
    raybonz likes this.
  21. mepellet

    mepellet Minister of Fire

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    So are we in agreement that hardibacker is not rated for hearth use? When we say "rated for hearth use," is there an ASTM number that is a test procedure for the manufacturers to do to get product certification? If so, what is the number that I should be looking for on the product cutsheets?
  22. raybonz

    raybonz Minister of Fire

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    I returned it and used the Durock NexGen as it is not combustible and has superior R-value..

    Ray
  23. mepellet

    mepellet Minister of Fire

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    I was just told by James Hardie that Hardiebacker 500 can be used if the manufacturer of the stove requires noncombustible construction. So maybe hardiebacker is the only approved cement board that can be used in a wood stove hearth???
  24. begreen

    begreen Mooderator Staff Member

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    Sounds like you are seeking the lowest common denominator here. Normally insulation value is fairly important with hearth design.

    I just sent a detailed email to USG asking for testing and approval for Durock NexGen. We'll see where this one goes. In the meantime I suggest commonsense be your guide.
    raybonz and Jags like this.
  25. mepellet

    mepellet Minister of Fire

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    I changed out the hardibacker for durock nextgen. Ripped out the hardwood flooring down to the subfloor (T&G boards on diagonal) last weekend. This weekend, I'll be putting down one layer of 3/8" plywood over the T&G boards and 1 layer of 1/2" durock nextgen on top of that then tile on top of that. In the meantime, gotta start figuring out what brand and where to purchase the chimney from. Any recommendations? Going to go straight up from stove through about 4' of attic space. Will do a 15 degree offset in attic because attic floor structure runs perpendicular to roof structure.....

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