How Do You Know if You Need Tuckpointing? Signs on Chicago Brick

How do you know if you need tuckpointing? Start with the mortar, because it is the part of the wall that is supposed to wear out first. Tuckpointing (also called repointing) is how you replace it before the brick pays for it (Brick Industry Association). The tricky part is spotting the point where "aging" becomes "needs work." Here is what to look at, from the sidewalk and up close.

What are the main signs you need tuckpointing?

Walk the building and look for these, roughly in order of how often they show up:

• Crumbling or sandy mortar. If grit sits on window sills or the ground below the wall, the joints are shedding.
• Gaps and hollow joints. Mortar that has receded behind the face of the brick, leaving a visible groove, or that has fallen out completely.
• Cracks running along the joints. Hairlines are normal wear. Cracks you can slide a fingernail into are not.
• Loose bricks. A brick that moves when you press it has no mortar behind it.
• Plants or moss rooting in the joints. They only grow where there is moisture and a gap.
• Water stains inside. Damp patches on interior plaster or paint near an exterior wall, especially after a hard rain.

None of these has a hard number attached. They are practical signs, not code tests. If you see several on one elevation, that wall is due.

How do you check the mortar yourself?

You do not need tools beyond a house key or a screwdriver, and safety glasses.

1. Scrape a joint. Mortar in good shape resists. Mortar that powders, crumbles or comes out in pieces has lost its bond.
2. Press the bricks. Nothing should shift.
3. Look at the pattern. Is the damage in one spot, or across a whole wall? One spot may be a downspout or a leak. A whole wall is age.
4. Check after rain. Look for dark, wet patches that stay wet longer than the rest of the wall.
5. Take photos. Date them. They help you compare year to year, and they help a mason scope the work.

Do not scrape hard enough to open up sound joints. You are testing, not repairing. For why DIY repointing goes wrong, see what you can and can't do yourself.

Why does the City care about crumbling mortar?

Chicago's existing-building code says the exterior of a structure must be maintained in good repair, structurally sound and sanitary. Among its listed unsafe conditions: masonry joints not maintained weather resistant or water tight, and veneer, cornices, trim and facings that are not properly anchored (City of Chicago, 14X). That is the language behind many masonry violations. We cover it in what Chicago code says about crumbling mortar joints.

What does water in the wall look like?

Water is what makes open joints expensive. Some signs it is already in the brick:

• White, chalky deposits (efflorescence). It needs soluble salts, water and a path to the surface. New brickwork can bloom white in its first year and then fade. Efflorescence that appears after a year usually points to excess water getting in or poor drainage, and it is often worst in winter (Brick Industry Association).
• Brick faces flaking, peeling or popping off (spalling). Salt crystallizing inside a brick creates pressure that can push off the outer surface. Freeze-thaw on saturated brick does the same thing (Brick Industry Association).

Spalling matters for a second reason. On soft old brick, mortar that is harder than the brick forces moisture and salts out through the brick instead of the joint (National Park Service). The repointing mortar should be softer and more vapor-permeable than the brick, and no harder than the original mortar (National Park Service). If your brick faces are failing, ask what mortar was used last time. We cover that in the mortar mistake that ruins Chicago brick.

What trouble spots look like tuckpointing but are not?

Tuckpointing fixes joints. It does not fix everything that shows up in a brick wall.

• Brick caps and copings. Their main job is to channel water away from the building. Brick caps with many mortar joints sit in the most exposed location and may be a poor choice compared with concrete, stone or metal (Brick Industry Association).
• Steel lintels over openings. Unprotected steel needs periodic maintenance. Cracking above openings is commonly tied to excessive lintel deflection from inadequate design (Brick Industry Association). Rust staining or a crack that follows the top of a window points to the lintel, not the joint. Lintels need flashing and weepholes (Brick Industry Association).
• Missing flashing. Through-wall flashing collects water that got behind the brick and directs it back out. It belongs at wall bases, sills, heads of openings, tops of walls, parapets and chimneys (Brick Industry Association).
• A wall that bulges, leans or has cracks through the bricks themselves. That is a structural question. Have a mason or engineer look at it before anyone grinds a joint.

If water keeps getting in, new mortar is a short-term fix. Find the source first.

When can you wait, and when not?

Waiting is reasonable when the mortar is dry and sound, with minor surface wear, and nothing is moving. That conversation belongs in is tuckpointing necessary.

Do not wait when any of these show up:

• Mortar gone or hollow across a good part of a wall.
• Loose bricks, especially above a sidewalk, entrance or alley.
• Spalling brick faces.
• Water stains inside, or rust at a lintel.
• A City notice about masonry.

A freeze-thaw winter turns small gaps into bigger ones.

What happens after you decide you need it?

A competent crew starts by looking at the whole wall, not just the front. The usual sequence:

1. Assess. Find out why the joints failed, not just that they did.
2. Pull the permit. Chicago lists tuckpointing as permitted masonry work through its Express Permit program (City of Chicago). See do you need a permit for tuckpointing.
3. Remove old mortar to the right depth. For most brick joints that is about 1/2 to 1 inch, or 2 to 2.5 times the joint width. Hand chisels are the traditional method. Power grinders only in skilled hands, and only on horizontal joints, with care (National Park Service).
4. Control the dust. Federal rules require a grinder with a shroud and dust collection, plus respirators for the crew (OSHA).
5. Repoint with a mortar that suits the brick. Softer and more permeable than the brick (National Park Service).

What moves the cost is the square footage of wall, access and scaffolding, how deep the joints have failed, the height of the building and what the inspection turns up behind the mortar. Anyone who quotes without looking at the wall is guessing.

Not sure what you are looking at? Send us photos or ask for a walk-through. Our tuckpointing crew will tell you if it is joints, water or something else. The whole picture is in the Chicago tuckpointing guide. If the mortar is already sandy, see mortar turning to sand.

Common questions

This article explains general rules and common situations in Chicago. It is not legal advice, and City rules change. For a specific property, check with the Chicago Department of Buildings or a licensed professional.