Here is a perfect example of a new wood look tile over a concrete foundation. We are ready to continue the flooring into the laundry room and noticed a different substrate (foundation) after the existing tile was removed.
It appears that a mortar bed was installed. Why is there a different substrate here? Could be several reasons be we think the house was remodeled and this was part of an addition or newer part of the house. Doesn't really matter the reason, we still have to deal with this situation.
Usually mortar beds are installed by the tile contractor using a Dry Pack consisting of 4-5 parts mortar sand and 1 part Portland cement that is mixed to a damp consistency. Mortar beds are usually at least 1 1/2 - 2 1/2 inches thick. This provides a solid substrate for the new tile installation.
So after removing the original tile, our next step was to remove the thinset mortar (white material used to bond tile to mortar bed).
But wait! Why are we removing the thinset mortar? Because we want a nice smooth and flat floor for our new wood look tile, right?
Well, yes but before we get too carried away, let's first check to see if the mortar bed is higher or lower than the adjacent concrete slab.
Look like the mortar bed is lower so it doesn't make sense to remove the white thinset.
Knowing this bit of information tells us that we can continue our tile installation using a modified thinset mixed to a fairly thick consistency. We use our level to make sure the tile flows into the laundry room at the same plane creating a smooth and professional transition.
Work smart not hard!