Here’s what to check, in order, starting from the roof down. This is not a comprehensive engineering report. It is a practical walkthrough you can do in an afternoon with binoculars and a flashlight. Chicagoland averages 80 to 100 freeze-thaw cycles per winter. The damage is done. Now you read it.
1. Chimney Crown
What it is: The concrete or mortar cap at the very top of the chimney structure, covering the space between the flue liner and the outer walls.
Stand back with binoculars. Look for cracks running across the crown surface, missing chunks, visible gaps where the crown meets the flue liner collar, or any vegetation growing from it. Moss and weeds mean the crack has been there long enough to host roots.
Red flag: Any crack you can see from 30 feet away is wide enough to be admitting water with every rain. Crown repair now costs $150 to $400. Crown replacement costs $500 to $1,200. Water traveling through a failed crown for another winter will cost you the difference. See Spring Chimney Crown Damage: The Winter Aftermath Homeowners Miss.
2. Upper Chimney Mortar Joints
What it is: The mortar between the top 15 or so courses of brick, above the roofline.
Scan with binoculars for recessed or missing mortar, crumbling material, or horizontal cracks along individual joint lines. This zone takes the worst freeze-thaw exposure on the entire house.
Red flag: Efflorescence streaking down the chimney face from this zone. White staining here means water entered through the crown or joints above and traveled down through the brick. See 5 Signs Your Chimney Needs Immediate Repair.
3. Chimney Lean
What it is: The vertical alignment of the chimney stack relative to the house.
Hold a finger up vertically and compare it to the chimney line. Any visible tilt away from the house, or any gap between the chimney and the house siding that is wider at the top than the bottom, means movement has occurred.
Red flag: Any visible lean is an immediate call. This is not a monitor-for-a-season situation.
4. Exterior Brick Wall Mortar Joints
What it is: The mortar between bricks on all four elevations.
Walk the perimeter slowly. Run your finger along suspect joints. Good mortar is firm and resists light pressure. Bad mortar crumbles or comes out. Focus on the north and east elevations first - they get more freeze cycles and less drying sun. Also check directly below window sills and above any door or window openings, where water concentrates.
Mortar that is recessed more than 1/4 inch, cracking along its length, or missing in sections needs tuckpointing this season.
Red flag: Wide-open joints, or joints that have completely washed out in sections. Open joints are direct water pathways into the wall cavity.
5. Brick Face Condition (Spalling)
What it is: The separation and loss of the fired outer surface layer of individual bricks.
Early spalling looks like fine crazing or thin flaking on the brick face. Later stages show concave depressions where the face has broken away, exposing lighter, softer interior material. Spring is when this becomes visible. The freeze-thaw cycle finishes its work during thaw, not during the freeze itself.
Red flag: Fresh spalling with clean fracture edges and light-colored exposed interior means this happened this winter. The exposed brick interior absorbs water at two to four times the rate of the original surface. Every winter you leave it unaddressed, the repair scope grows. See Why Brick Spalling Appears in Spring.
6. Window and Door Perimeter
What it is: The masonry surrounding all window and door openings.
Look for cracks radiating from window corners at 45-degree angles - this is the classic stair-step crack pattern. Also check for gaps between window frames and the surrounding brick, and for efflorescence on the brick directly below window sills.
Red flag: Rust staining on the brick below window or door openings. This indicates the steel lintel inside is corroding and expanding, which cracks the mortar and will eventually displace the brick above it.
7. Foundation Perimeter
What it is: The visible foundation wall above grade, including any parging coat.
Walk the foundation and distinguish crack types. Vertical cracks are common and often not urgent. Horizontal cracks, running across the wall, indicate lateral soil pressure - more serious. Stair-step cracks following mortar joints diagonally indicate settlement or movement.
If the foundation has a parging coat (smooth mortar plaster applied to the exterior face), check for areas where it has cracked, delaminated, or pulled away from the wall below.
Red flag: Horizontal cracks in a block or brick foundation, especially if one side of the crack is displaced relative to the other. Get professional eyes on this before the next freeze season.
8. Efflorescence on Any Surface
What it is: White, powdery, or crystalline mineral deposits on any masonry surface.
Efflorescence is not a problem. It is a symptom. The white powder tells you where water moved through the masonry and evaporated. Its location points to the water entry pathway. Widespread efflorescence across multiple elevations after a single winter indicates systematic joint failure, not an isolated issue. See Efflorescence and White Staining in Spring.
Red flag: Efflorescence that reappears within a week of being cleaned, or efflorescence accompanied by crumbling mortar or spalling in the same area.
9. Concrete Flatwork
What it is: Driveways, walkways, stoops, and garage aprons.
Look for scaling (the surface layer peeling away in irregular patches, exposing aggregate), spalling (deeper chunks breaking out), and linear cracks running parallel to slab edges. Also check control joints - the saw-cut lines in the slab - for failed or missing caulk.
Red flag: Long, straight cracks parallel to the driveway edges that do not align with control joints. These may indicate rebar corrosion below the surface from chloride penetration. Tap the surrounding concrete with a screwdriver handle - a hollow sound means delamination below. See Spring Concrete Damage: How to Spot De-Icer Salt Failure.
10. Wall Caps and Coping
What it is: The masonry or stone cap on top of any garden wall, retaining wall, or parapet.
Horizontal surfaces collect water. They are the most vulnerable point on any freestanding wall. Check coping stones for cracks or shifted positions, look at the mortar at the cap line for open joints, and scan the wall face just below the cap for efflorescence streaking.
Red flag: A coping stone that has shifted out of position means the mortar joint beneath it has failed. Water is entering the wall from above at that point.
When to call a professional: chimney lean, horizontal foundation cracks, active water in the house near any masonry element, or efflorescence spreading across multiple elevations simultaneously. For timing on scheduling repairs once you have your list, see When to Schedule Tuckpointing in Illinois: Why Spring and Early Summer Win.
Delta Masonry & Tuckpointing provides free inspections in Winnetka, Wilmette, Glencoe, Lake Forest, and surrounding North Shore and Lake County communities. Call (847) 713-1648 or contact us online.