A fastener plate for use in coupling an underlayment to a roof surface is disclosed. In use, the fastener plate is arranged and configured to enable subsequently applied liquid coatings to flow through a top surface of the fastener plate and into one or more cavities so that the liquid coating seals any openings created by introduction of the fastener. In one embodiment, the fastener plate may include a top surface, a bottom surface, a fastener opening for receiving a fastener, a plurality of openings formed in the top surface, and one or more cavities positioned between the top surface and the bottom surface, the one or more cavities being in fluid communication with the plurality of openings so that the liquid coating can flow through the plurality of openings formed in the top surface and into the one or more cavities to seal any voids created by the fastener.