Mix one part Portland cement and one part plaster sand with enough water to create a mixture the consistency of thick frosting. If you are applying the brick to a vertical surface, spread a thin 1/4-inch coating of this mixture over the surface using the trowel. Scoop off excess by dragging the trowel at a 45-degree angle. Discard any crusted mortar or mortar that begins to dry.
Snap a chalk line on the mortared surface as a guide. Take your first brick and spread mortar at least 1/2 inch thick on the back, bottom and sides. Press the brick onto the vertical surface. Wiggle it back and forth and allow the mortar to squeeze out. This creates suction that will cause the brick to adhere. Butter another brick with mortar and press it in next to the first.
Continue the bottom layer by adding bricks next to each other. Follow the chalk line, adjusting as needed by adding a thicker layer of mortar. Wait half an hour and then push the mortar into the joints with a joint tool. Let half an hour more pass and then use a wire brush to clean off the face of the brick.
Continue laying the next layer of bricks but in an alternating pattern to the first layer. Select a broken brick or cut one for the first piece, which will start the pattern off staggered. When you are done laying all the bricks, clean the faces and cracks between completely with the wire brush.
Apply grout after 24 hours. Mix one part Mason's cement with two parts silica sand and add water until it is spreadable. Fill a grout bag halfway with the grout. Roll the top down to get rid of air bubbles. Once the flow of grout is consistent, run the tip of the grout bag along the cracks between each brick. Smooth out the grout as needed with a trowel.