Tuckpointing vs repointing, and how to tell your joints are due

If you call a mason around here and ask for tuckpointing, he knows what you mean: the old mortar is shot and you want new mortar in the joints. That is the everyday meaning, and it is how this site uses the word.

Strictly speaking, though, the general job is called repointing. Tuckpointing is an old technique where the joints are filled with mortar colored to match the brick, and then a thin, neat line of contrasting mortar is tucked into the middle of each joint so the brickwork looks crisper than it really is. True tuckpointing like that is mostly seen on older city buildings. On a house in Hoopeston, the work you need is almost always repointing, whatever you call it.

The steps are simple to describe and take skill to do well. The failed mortar is cut or raked out of the joints to a consistent depth, down to sound material, without chipping the edges of the brick. The joints are cleaned out. New mortar is packed in, usually in layers if the joints are deep, and then the surface is tooled to a finish that matches the rest of the wall.

Then the mortar has to cure properly, which means not drying too fast in summer heat and not freezing in cold weather.

• Old mortar cut out to sound material
• Joints cleaned of dust and debris
• New mortar packed in, in layers if deep
• Joints tooled to match the wall
• Cured without baking or freezing

Go look at the wall, especially the parts that get the most weather: the chimney, the bottom of the walls, under gutters and around windows. Mortar joints that are due will show one or more of these signs.

The mortar has sunk back from the face of the brick so you see a little ledge. It is cracked, or cracked away from the brick along the edge. It crumbles when you scrape it with a key. There are holes where mortar has fallen out. Or the brick next to it has started to crack or flake, which can mean water is getting in through bad joints.

There is no fixed schedule. Good mortar in a sheltered wall can last a very long time. Mortar on a chimney top or a wall that takes driving rain wears out much faster. Old lime mortar wears faster than modern mortar, which is the way it is meant to work.

The practical answer is to look at the joints every year or two, and repoint where they have worn, rather than waiting until the whole house needs it at once.

Not every job is the whole house. Often the chimney and one weather side need repointing and the rest of the house is fine for now. Spot repointing those areas costs much less and keeps water out where it matters most.

The catch is matching. New mortar in a patch should match the old in color, texture and hardness so it does not stand out or cause trouble. On old soft brick, the new mortar should never be harder than the brick.

Mortar joints are the part of a brick wall that is supposed to wear out. They are the easy, cheaper part to replace. When they are left too long, water gets past them and into the brick and the wall behind, and then you are paying for brick replacement and sometimes rebuilding, not only new mortar.

If you are not sure your joints are due, send Brian a close photo of a few joints with a key or coin in the shot for scale. Text it with your town to (217) 549-2230.