Siding Installation and Repair
Many Ontario homes built from the 1950s through the 1980s have exterior stucco that has reached the end of its useful life. Installing new siding over stucco is a common renovation approach — one that requires understanding of the specific challenges involved.
Stucco condition affects the approach significantly. Stucco in generally sound condition can serve as a substrate for new siding installation. Stucco with widespread cracking, moisture damage, or delamination may need partial or full removal first.
Material Selection Guide
Substrate preparation typically involves installing horizontal strapping (furring strips) over the existing stucco to create a flat, level surface for siding installation and a drainage plane between the new siding and the stucco.
Moisture management is the critical design decision. Water will reach the back of the new siding — it must have a drainage path rather than accumulating behind the panels. Strapping creates this drainage space; housewrap over the strapping establishes a clear drainage plane.
What the Installation Process Looks Like
Window and door reveal adjustment is necessary. Adding strapping and new siding increases the exterior wall depth, changing the relationship between the window frame and the new exterior cladding plane. Trim details must be adjusted accordingly.
Permit requirements vary by municipality. The project may trigger Building Code compliance review for the new cladding and potentially for the underlying wall assembly. Check with your local building department before proceeding.
Cost relative to full removal is context-dependent. Over-cladding avoids demolition and disposal costs but adds strapping material and labour. Full removal gives better visibility of underlying conditions and more design flexibility at the window openings.