A roof mounting system can include a roof substrate and flashing supportable on the substrate and including an outwardly extending projection having a concave interior side and an aperture extending through the projection between top and bottom surfaces of the flashing. A seal can extend through the aperture and contact at least a portion of the top surface and at least a portion of the bottom surface. The seal can be conformable with the concave interior side and can define a seal aperture substantially aligned with the flashing aperture. A mounting bracket can be supportable on the flashing and can define an aperture sized to receive at least a portion of each of the seal and the projection. A fastener can extend through the mounting bracket aperture, seal aperture, and flashing aperture to inhibit fluid flow through the flashing aperture.