Step-by-Step

Chisel out the joints: With a baby sledge and a cold chisel, remove mortar from joints to a depth of 3/8 to 1 inch. It is possible to tuckpoint without chiseling out old mortar, but the tuckpointing will not last as long. Because chips will fly as you work, wear safety goggles and heavy gloves.

OR use a grinder: If you need to work on a large area, rent or purchase a 4-inch grinder to efficiently remove old mortar. Whichever method you use, if the joint crumbles easily all the way through the wall, tear down the whole section and re-lay the bricks with new mortar. Tuckpointing by itself will not add strength to weak masonry joints.

Use the point of a cold chisel or the tip of a pointed trowel to scrape away patches of mortar that remain after chiseling or grinding. Briskly sweep away debris with a stiff whisk broom. Mix the mortar using 1 part Portland cement to 2 parts masonry sand and enough water to form a puttylike consistency (see Working with Mortar, Related Projects).

Load an upside-down trowel with mortar and hold it against the wall. With a 3/8-inch back filler, force the mortar into the joints. Fill the head (vertical) joints first, then the bed (horizontal) joints. It will take practice before you can tuckpoint without dropping mortar or smearing bricks.

Use a damp sponge to wipe away excess mortar while it is still wet. Brush the joints to remove mortar crumbs. Correct timing is essential for striking the joints. The mortar should be stiff, but not hard. Choose the appearance of your joint from those shown in Choosing a Mortar Joint, Related Projects.

To ensure that your joints are watertight, strike them a second time, making sure they seal tightly against the bricks. Let the mortar set up somewhat, then brush away crumbs with a stiff brush. Scrub mortar stains off the wall within 24 hours.