Interior sills located directly above radiators are prone to cracking because the concentrated heat dries out materials and causes localized expansion. 2. When to Worry: Is It Structural?
Cracks typically develop due to the natural stress windows endure from environmental changes. crack under window sill
Materials like wood, vinyl, and concrete expand in the heat and contract in the cold. This constant movement eventually causes the rigid plaster, drywall, or mortar beneath the sill to fracture. Interior sills located directly above radiators are prone