Cut a window opening in a brick wall last summer. Spent more time worrying about the lintel than actually installing it. Turned out fine, but brick makes you earn every modification.
The Challenge with Brick
Brick walls look great and last forever. They’re also heavy, rigid, and completely unforgiving when you cut into them. One wrong move and you’ve got a repair that costs more than the window itself.
That said, thousands of windows get installed in brick every day. The process is well understood. Just requires planning and precision.
Window Types That Work
Sash windows – Classic double-hung style. Still looks right on older brick buildings. The up-and-down operation doesn’t stress the frame much.
Casement windows – Hinged on the side, crank to open. Good ventilation. Modern look but works fine in brick if proportioned right.
Fixed windows – Don’t open at all. Simplest to install and most weather-tight. Use these where you want light but don’t need ventilation.
The Lintel Situation
This is what keeps the brick above your window from falling into your living room. Non-negotiable structural element.
Steel angle lintels are most common. Size depends on the span and the load above. Concrete and sometimes wood lintels exist too, depending on the building and era.
If you’re cutting a new opening, the lintel goes in first before you remove brick below. Get this wrong and things get expensive fast.
Frame Installation
The window frame usually sits slightly recessed into the opening. Looks better and protects the frame from weather exposure.
Level and plumb matter. Shims adjust the fit. Masonry anchors secure the frame to the brick. Then caulk seals the perimeter against water and drafts.
Sealing and Insulation
Water getting past the frame causes problems. Caulk the exterior joint completely. Use backer rod in larger gaps before caulking.
Foam insulation fills the gap between frame and rough opening. Closed-cell foam for wet climates. Don’t over-expand or you’ll bow the frame.
Finishing Details
Exterior sills slope away from the window to shed water. Stone, precast concrete, or metal all work. The sill needs flashing underneath.
Interior trim varies by taste. Simple wood casing works. Drywall returns give a cleaner modern look. Match the rest of the house.
Maintenance
Check caulk joints annually. Brick and window frames move at different rates with temperature changes. Caulk fails eventually.
Look for cracks in the brick above the window. Can indicate lintel issues. Usually fine, but worth monitoring.
Clean weep holes if your windows have them. Blocked weeps mean water stays in the frame instead of draining out.
DIY vs Professional
Replacing an existing window in an existing opening? Manageable for a competent DIYer. Careful measuring, proper flashing, good caulk technique.
Cutting a new opening through brick? Hire a professional unless you know exactly what you’re doing. Structural implications, load paths, lintel sizing. Too much can go wrong.
