Masonry & Brick Sealer should be breathable and allows water vapor to escape. Liquid water, especially from wind driven rains, will stay out of the brick and masonry. Sealing of masonry can resolve brick flashing issues if done by a most reputable waterproofing contractor.Sealing masonry or stone will stop water vapor from the interior of the building, or from the underside of pavers can escape. This will reduce efflorescence, spalling and scaling that can occur from water being trapped inside the brick substrate and freezing during cold weather. Penetrating commercial grade sealers leaves no surface film to wear away and maintains surface textures. Please further note if non-professional´s applications are applied to any substrates it then will be too late to hire a professional.