Clean the WallAn older brick surface will often need cleaning. A brass brush and lots of water works well and is cheaper and less messy than sand blasting or power washing. It does not stain old brick like muriatic acid can either. You will need a number of these brushes – as they wear out relatively quickly – and several hours of free time. Make certain to cover the floor with a plastic drop cloth. As with all such projects, work on a small, less conspicuous section before venturing on to the entire wall.
To keep the water from running off your plastic sheeting, place a 2x4 barrier under the plastic in the shape of a ‘U’ and run the open area of the plastic up the wall wrapped in a 1x2 to create a basin. Using a nail gun, nail the 2x2 to the mortar in two places. When you have finished, just remove the nails, as later you will be filling cracks with grout anyway. Another option is to stick the lip of the plastic to the wall with a cheap silicone caulk. It will peal away and you can clean that part of the wall last.
Repair Bricks and MortarWhen you have completely cleaned your old brick wall, you will want to fill in cracks and missing mortar. Buy a coloured grout that matches the old and weathered mortar, testing in an inconspicuous area first.
Preserve Your WorkTwo good choices for sealing an old brick wall are polyurethane and silicone. Both will give the brick a clean appearance and protect the brickwork. Polyurethane gives a slightly shinier appearance, while a silicone sealer tends to deepen the brick color but will not otherwise be noticeable. In each case, you will be working with irritating and volatile materials so make sure you work with the windows open and on small spaces of wall at a time. Take breaks in the fresh air after each patch of wall you finish. Ideally, you will do this job in the summer and leave the windows open for a day after finishing the wall.
Consider a bright and modern look to contrast with your nicely cleaned, repaired and sealed brick wall. Using your nail gun, you can drive cement nails into the brick to hang supports for modern chrome light fixtures. For securing more substantial objects, use a tool such as the Makita LXT202. This 18V LXT Combination Drill & Impact Driver Kit is excellent for making the holes for anchoring heavier items such as a built-in bookcase of lightly stained mahogany.