The Problem
A property owner on the Central Street commercial corridor in Evanston contacted us after a tenant noted that the display window frames on the ground floor unit were becoming difficult to open. On inspection, we found the cause: both steel lintels spanning the two storefront window openings had corroded and expanded, pushing the brick courses above them outward and upward. The classic stepped crack pattern had developed at both window corners, with one crack on the south window running 18 inches up the facade before terminating. Three brick courses directly above the failed lintels had displaced outward by as much as 3/8 inch. The facade was stable but the lintels were no longer carrying load correctly. The 1925 mixed-use building had been through several tenant cycles and the lintel condition had not been documented in any recent inspection.
Our Solution
We submitted the permit application and received approval before mobilizing. A tube scaffold was erected across the full storefront width and the building front was netted at pedestrian level for the duration of the structural phases.
The displaced brick above each lintel was numbered, removed, and stored. Both corroded lintels were extracted and replaced with hot-dip galvanized steel lintels sized to the original span. Galvanized lintels are our standard specification on masonry facades within two blocks of Lake Michigan because salt air accelerates plain steel corrosion significantly. The replacement lintels were set with a slight positive camber of 1/8 inch to account for long-term deflection under sustained load.
Displaced brick was reset in the original sequence using Type N lime-based mortar batched to match the 1925 joint color, a warm cream-gray common on Central Street storefronts of this era. All stepped cracking was stitched using stainless helical tie bars inserted into horizontal slots at 16-inch vertical intervals, then grouted and pointed flush. The full facade received a rake-and-repoint to 3/4-inch depth in two lifts. Parapet cap joints were repointed and sealed at the coping terminations.
The Result
Both storefront window frames operate freely following the lintel replacement. The stepped cracking is stitched and pointed, with no visible shadow lines at the repair zones. The full facade repointing presents a uniform joint color and profile from grade to parapet. Structural inspection passed without comment. The property owner has a written record of lintel type, dimensions, and camber specification for the building maintenance file.
