A one-component, roll-on moisture membrane.

Bona® R540 is a polyurethane reactive primer that is compatible with the entire Bona Adhesive System. It is specially designed to mitigate vapor transmission on absorbent and non-absorbent floors, including Gypsum-based underlayment.

*Only one coat needed when used with 1250G or 1500G trowel and any Bona Adhesive. Two coats required in all other installations when the above criteria is not met.