What are window sashes

What are Window Sashes

The sash holds your window's glass panes in place. It's the movable frame that lets you open and close the window, directly affecting ventilation and insulation. Some sashes are fixed, others move—a crucial distinction in both old and new designs.

Types of Window Sashes

Single-Hung: Bottom moves, top stays put. Common in older homes—classic look, less maintenance.

Double-Hung: Both top and bottom sashes move independently. Better airflow and easier cleaning, especially with tilt-in designs.

Sliding: Moves horizontally on tracks. Perfect for modern spaces or where swing-out windows won't work.

Fixed: Non-opening window that maximizes insulation and views without compromising energy efficiency.

Materials Matter

uPVC: Virtually maintenance-free, energy-efficient, popular in newer construction.

Timber: Traditional beauty that needs regular care to prevent warping and rot. Standard in heritage homes.

Aluminum: Strong, sleek, weather-resistant. Modern look with thermal breaks for better insulation.

Composite: Blends materials for the best of all worlds—looks like wood but performs better in harsh weather.

Why Sashes Impact Performance

A quality sash improves insulation, cutting heat loss and energy bills. Reinforced sashes with good locks boost security. Well-designed sashes also control airflow more effectively.

Common Sash Problems

Warping/Rot: Moisture ruins timber. Regular sealing is essential.

Drafts: Gaps develop as sashes age. New weatherstripping helps.

Sticking: Paint buildup or humidity can jam frames. Sand lightly to fix.

Failing Hardware: Locks and handles wear out. Check them yearly.

The right sash keeps your home comfortable, secure, and efficient. Worth understanding before you buy new windows or upgrade existing ones.