Which material offers a clean, vertical edge for bonding while reducing potential grout contamination?

The material that offers a clean, vertical edge for bonding while reducing potential grout contamination is high solids/cold liquid applied membrane. This type of membrane is designed to create a seamless barrier that significantly reduces the risk of contaminants, such as dirt and moisture, from interfering with grout adhesion. Furthermore, it ensures a smooth, clean surface that provides strong bonding characteristics, which is essential in tiling applications.

Using a high solids/cold liquid applied membrane not only protects the integrity of the grout but also maintains the optimal conditions for various substrates. This is crucial in ensuring a durable installation that withstands various environmental factors.

Other materials mentioned, such as polyethylene sheeting and reinforced asphalt paper, may provide some level of moisture barrier but do not specifically address the need for a clean bonding edge or reduce grout contamination as effectively. Acid washed surfaces primarily pertain to the preparation of concrete for better adhesion but may not provide the same level of protection against contamination as the high solids membrane does.