We couldn’t do without water, but the damage it can do! If you have a brick wall, chimney or garden wall, you may have noticed crumbling mortar between bricks. The longer you leave this, the worse it will get as water works deeper into the joint. So tackle it right away.
(Just work on a small section of the wall at a time, so you don’t weaken the wall.)
With a small cape chisel and a small heavy mallet, knock out any loose mortar. Use short, sharp taps; you don’t want to knock out an entire brick. Chisel to a depth of 1/2″ to an inch and clean out the groove with a wire brush. Finish up with a paint brush to get rid of any dust.
Now you’re ready to put in the mortar. Don’t use a concrete mix. Concrete’s too stiff, and won’t allow bricks to expand and contract as they get wet. Pick up premixed mortar and add water as necessary to small amounts of the mix.
Wet the brick and the groove down with water, so it won’t suck moisture from the mortar, then, using a trowel, fill the groove tightly right to the back.
One technique is to use your trowel to shape and slice a small “sausage” of mortar, then tip it into the groove. After about an hour, use your trowel, a copper pipe, or a special mason’s tool to shape the joints (or “point” them).
Once the joint has dried a bit more, brush it diagonally with a wet, stiff bristle brush. Wet the area regularly for the next month.