Undesired migration of materials in the adhesive to the surface of the floor between tile joints.
· Too much adhesive used; improper trowel notching.
· Placing the tile into the adhesive too soon; not allowing the proper open time.
· Moisture from the subfloor or improper maintenance.
· Solvent seeping up from the subfloor and softening the adhesive; due to solvent-based cleaners, spills, etc., on the subfloor.
· Use of no-rinse strippers within the first two years of the installation.
If due to moisture, little can be done to correct the problem. However, if due to moisture because installation was done on green concrete, the slab can be allowed to dry, and installation redone. If due to solvent in subfloor, and adhesive is very soft, it may help to remove the tile and allow solvent to evaporate. However, there may be little that can be done if the solvent has gotten into the subfloor itself such as from cleaning old adhesive residue using an adhesive remover which contains a solvent. If due to other reasons, increased maintenance following recommended procedures will be necessary to keep surface of flooring free of excess adhesive. This will prevent tracking of the adhesive until all excess has bled to surface, or adhesive has set. When tile is set into the adhesive without allowing the proper open time, there is no way to determine how long it will take for the adhesive to dry. This will be dependent upon the type of subfloor, moisture content (for concrete), temperature, humidity, air flow, trowel notching, etc.