Are you a subscriber but don’t have an online account?

Register for full online access.

 
 
 
 
+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 15 of 21
  1. #1
    Join Date
    Oct 2007
    Location
    Portland, Oregon
    Posts
    1,375

    Default Modified vs unmodified thinset

    What is the difference? Are they for different applications?
    Tom

  2. #2
    Join Date
    Jun 2004
    Location
    Friday Harbor, San Juan Island, Washington
    Posts
    13,029

    Default Re: Modified vs unmodified thinset

    That's a big topic. I suppose to cover the basics you can say that modified is stickier and stronger, and it's what you want to use with porcelain tile.

  3. #3
    Join Date
    Oct 2007
    Location
    Portland, Oregon
    Posts
    1,375

    Default Re: Modified vs unmodified thinset

    Ok, but my thought is then why do they manufacture unmodified? Are there applications where modified would be unsuitable, and you would need to use unmodified?
    Tom

  4. #4
    Join Date
    May 2006
    Location
    NJ
    Posts
    5,832

    Default Re: Modified vs unmodified thinset

    Unmodified is used in applications where there is the inability for the moisture to evaporate through the either the substrate or the tile above.

    For example....where tile is installed over Ditra. The thinset is sandwiched between the ditra (plastic) and tile and has little surface area for the moisture to escape and allow for curing, so an unmodified thinset is used because it will cure with minimal or no availability for the moisture to evaporate.

    This is what the representative from schluter explained to me at a show a few years back.

    Look at this diagram on page 12

    http://www.schluter.com/media/DitraH...9-2007-ENG.pdf
    Last edited by always-learning; 05-02-2008 at 11:12 PM.
    Chuck

  5. #5
    Join Date
    Apr 2008
    Location
    Calgary Alberta Canada
    Posts
    61

    Default Re: Modified vs unmodified thinset

    Sometimes it is just the expense. Why spend money on polymers which are not needed.
    When you are installing over concrete that is sound you do not need modified mortar as it will stick just fine and will not be subjected to flexing, but on plywood floors where movement is likely it is best to use a high grade thinset with lots of admix.

  6. #6
    Join Date
    Aug 2004
    Location
    Alberta, Canada
    Posts
    517

    Default Re: Modified vs unmodified thinset

    If you read discoloration in light grout you will learn from our mistake that unmodified thinset is suitable and unmodified not suitable for when using the Kerdi/Schluter system.

    Nicole

  7. #7
    Join Date
    Jun 2004
    Location
    Los Angeles, CA
    Posts
    4,264

    Default Re: Modified vs unmodified thinset

    Quote Originally Posted by Nickymg View Post
    If you read discoloration in light grout you will learn from our mistake that unmodified thinset is suitable and unmodified not suitable for when using the Kerdi/Schluter system.

    Nicole
    I read this twice and can't understand it. Is there a typo or am I just tired?

  8. #8
    Join Date
    Aug 2004
    Location
    Alberta, Canada
    Posts
    517

    Default Re: Modified vs unmodified thinset

    I think I am tired - it does not make any sense at all! Sorry, do not worry about it. I am not tile expert.
    Nicole

  9. #9
    Join Date
    Apr 2006
    Location
    Kiawah Island, S. Carolina
    Posts
    1,211

    Default Re: Modified vs unmodified thinset

    Dry-set thinset mortar has no polymers and is basically sand, cement, and some retarder. It is the first thinset mortar developed (no, it was not engineered specifically for Schluter products). You can add a liquid latex or acrylic in place of water to make a modified thinset. Dry-set thinset mortar will not stick to wood after curing.

  10. #10
    Join Date
    Mar 2008
    Location
    Jacksonville, Fl. (Dinsmore)
    Posts
    236

    Default Re: Modified vs unmodified thinset

    Are you sure about those facts Mr. Byrne? I thought Herr Schluter invented unmodified after creating the Internet with Mr. Gore? :)

  11. #11
    Join Date
    Aug 2006
    Location
    SE PA
    Posts
    504

    Default Re: Modified vs unmodified thinset

    Quote Originally Posted by mbyrne View Post
    Dry-set thinset mortar will not stick to wood after curing.
    Mike, could you explain this a bit more. I don't understand what you mean by "dry-set thinset mortar". But since I'm just a GC, not a tile setter, I think you will understand. Thank you.

    Regards,

    Tom

  12. #12
    Join Date
    Jun 2004
    Location
    Los Angeles, CA
    Posts
    4,264

    Default Re: Modified vs unmodified thinset

    Thinset morter, when "dry" will no longer adhere to plywood. That is why modified was created.

  13. #13
    Join Date
    Mar 2008
    Location
    Jacksonville, Fl. (Dinsmore)
    Posts
    236

    Default Re: Modified vs unmodified thinset

    Dryset mortar and unmodified is the same thing.

  14. #14
    Join Date
    Aug 2006
    Location
    SE PA
    Posts
    504

    Default Re: Modified vs unmodified thinset

    Quote Originally Posted by scuttlebuttrp View Post
    Dryset mortar and unmodified is the same thing.
    Thank you! Now I understand.

    Tom

  15. #15
    Join Date
    Dec 2005
    Location
    Michigan
    Posts
    7,606

    Default Re: Modified vs unmodified thinset

    Quote Originally Posted by always-learning View Post
    Unmodified is used in applications where there is the inability for the moisture to evaporate through the either the substrate or the tile above.

    For example....where tile is installed over Ditra. The thinset is sandwiched between the ditra (plastic) and tile and has little surface area for the moisture to escape and allow for curing, so an unmodified thinset is used because it will cure with minimal or no availability for the moisture to evaporate.

    This is what the representative from schluter explained to me at a show a few years back.
    That's a good-sounding theory but it doesn't hold any water (pun intended).

    Custom guarantees modified over Redgard. Actually they require it. From Redgard data sheet:
    TILE INSTALLATION
    Install tile or stone with a Custom® polymer-modified mortar meeting ANSI A118.4 or A118.11 standards.

    Schluter must know something we don't. Or they may be relying on technical advice from Mr. Gore :)

    dg

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts