[mrkartheiser]

I am having an issue with my newly remodeled bathroom. I had marble flooring installed and a heating element installed under neath the marble. There was a concrete leveling mix poured over the entire floor so that it would be perfectly level. I took pictures of the work while the contractor did it. I went around and asked people ans no one has ever seen this. I even asked the tile sales rep and he said he has never seen it. The contractor said to just leave the heating element off for a couple months that the concrete in the seems was not dry 100% and that is why it is making lines. I am afraid that it will never go away. Can someone help with this issue and how to get rid of these. I can't upload pictures but I can email them to you if there is someone that can help.

 

[oh'mike]

You need to have 2 or 3 posts before you can post a picture---we will need one to fully understand the issue---

Some odd discoloration happens while the thinset and self leveling compounds are curing--but should vanish when the setting materials are completely cured--

What color and type of marble?

When was the work completed?

 

[Mingledtrash]

Sounds like maybe this:

Definition of Efflorescence:Efflorescence is the white powdery substance on the surfaces of unsealed concrete and the white blush seen with sealed floors. Efflorescence is caused by vapor migrating through the slab bringing soluble salts to the surface of the concrete. Efflorescence is normally worn off or washed away on unsealed concrete surfaces. In stubborn cases, a mild acid rinse or even a light sandblasting may be necessary. Efflorescence that becomes trapped under sealer is unsightly and is even more conspicuous on darker floors.
In worst case scenarios where the vapor cannot pass through the top coat, a urethane and/or an epoxy for instance, hydrostatic pressure can build to create water blisters indicating delamination of the top coat from the concrete.

http://www.concretenetwork.com/doug_bannister/efflorescence.htm

full article mentions that excess water contributes to Efflorescence. Then you have marble on top. marble is pretty porous.