how to know what thinset is unmodified

[KMD]

I am getting ready to hang some kerdi membrane. From reading kerdi info, they want unmodified, and John Bridge likes slightly modified. My question is I have been to two different stores (Lowes and our local hardware) and I dont see anywhere on the bags where it says (modified, unmodified, or slightly modified). Any help would be appreciated.
Thanks
Kevin

[ddmoit]

Hi Kevin,

If you're shopping at Lowe's, they should have one of these three unmodified thinsets:

Kerabond (Mapei)
Laticrete 317 (Laticrete)
MegaBond (Laticrete)

[jgleason]

Unmodified may also be described as dry set.
Modified may also be described as fortified.

[Brian@BC contracting]

Kevin...do yourself a favor and heed the advice of others here,and find the ditra set unmodified made by bostik company almost especially for the schluter system if you want to stay unmodified.If you dont buy that brand,make sure you dont buy a economy style mortar in the 6 dollar range,as they dont have enough bonding strength in my opinion. Look at spending ten plus dollars on a better product!! Only area i went modified was on my ceilings in my steam room,but only on the exposed side of the kerdi,not the portion which was scratched on to the cement board. Im leaving my grout lines open for a few weeks while waiting for my steam door to be made for the modified to help cure some.

Good luck, BC

[athenslb57]

I am using this for my Kerdi and John really likes it as well.

http://www.custombuildingproducts.co...er=diy&lang=en

Hi Kevin, the most common way that you could determine if a thinset is modified or not is to read the instructions for mixing, and if it says something to the effect of "add X amount of water only", then it is already modifed.

If it says "mix with X amount of water, or use additive such-and-such in place of water", then it is unmodified.

I hope this helps.

[Cashflow]

Brian,

I am getting ready to set the ceiling tiles in our Kerdi shower. Was going to use Versabond which is what we used to put the Kerdi on with. Do you recommend a product that is highly modified or quicker setting for the ceiling? Just curious, I don't want the tiles crashing to the floor.

[The Kid]

vern, what size tiles are you using? Either there going to stick up there or there not reguardless of type of thinset, alot of what your worried about there is dictated on your installation methods.

I would use an unmodified, probly laticrete 317 or if you do decide you absoultlly need the stickyness of a modified use a rapid set morter.

[cx]

Kevin, you can best tell by looking for the ANSI standard marking on the bag.

If the pookey meets A118.1 when mixed with water, it's unmodified, or dry-set mortar.

If it says it meets A118.4 and/or A118.11 when mixed with water, it's a modified thinset mortar.

No guesswork.

My opinion; worth price charged.

Kelly, my way is easier....no codes or ANSI-speak to remember.

[Cashflow]

Jeremy,

The tiles are 3x3, I've been thinking I will just give the Versabond a try since I have it already. They have some quickset stuff at Home Depot but I'm headed to a bigger city and they have a Lowes. I'll look for the Laticrete while I'm there. Thanks for the advice.

[jgleason]

Hi Vern,
Versabond will be just fine. 3x3 tiles won't be a problem at all on the ceiling.