If the mortar is not sealed, it will show through. In order to prevent this from happening, use common masonry supplies. Whitewashing brick can be done using typical masonry materials like paint or stain. Whitewashing brick can be done with the most common materials for masonry by watching the YouTube video “How to Whitewash Brick With Masonry”.
Mix the mortar together in either a mixer or bucket. after which you add water until it is just dry enough to move easily using your hands. Make use of a trowel for applying the mortar on your bricks. Then, ensure that each brick row is filled with mortar that is wet.
Next, let the mortar dry over night before painting and stain the surface. In order for stain or paint to adhere to damp surfaces like bricks and concrete slabs use greater pressure than normal. Then, apply a paintbrush or roller to apply painting over small gaps or cracks between bricks, allowing moisture into the bricks over time.