Why are Espags used in Sliding Systems?

While sliding windows and doors primarily rely on rollers and a simple “crescent lock” or “touch lock” for basic closing, more secure uPVC sliding systems incorporate espags for multi-point locking.

• Enhanced Security: A sliding espag will typically have multiple locking points (cams, hooks, or a combination) that engage into keeps on the fixed frame, providing significantly more security than a single-point lock.

• Improved Compression/Weather Sealing: The multi-point locking action of an espag pulls the sliding sash tightly against the frame when locked, creating a better seal against dust, drafts, and water ingress.

• Smooth Operation: When unlocked, the espag disengages all points, allowing the sash to slide freely.

Key Features of uPVC Sliding Espags with 7.5mm Backset:

• Narrow Profile Compatibility: Specifically designed for uPVC profiles with a shallow backset requirement, common in some sliding systems.

• Locking Points: Will have multiple locking points along its length (e.g., 2, 3, or 4 points), which could be mushroom cams, roller cams, or hooks.

• Length: Available in various lengths to suit different window/door heights (e.g., 400mm, 600mm, 800mm, 1000mm, 1200mm, 1400mm, 1600mm, 1800mm, etc.). You’ll need to measure your existing one.

• Handle Operation: Operated by a handle (often a D-handle or a flush-fitting handle) that turns a spindle to engage/disengage the locking points.

• Material: Typically zinc-plated steel with corrosion-resistant coatings (e.g., passivation) to ensure durability.

Identifying Your Specific Espag:

To ensure you get the correct replacement:

1. Remove the existing espag: This is the best way to get all the critical measurements.

2. Measure the Backset (7.5mm): Confirm this by measuring from the edge of the faceplate to the center of the spindle hole.

3. Measure the Overall Length: Measure the full length of the espag faceplate.

4. Count and Identify Locking Points: Note how many locking points there are and their type (cams, hooks, etc.).

5. Note Brand/Model (if any): Look for any stamped numbers or logos on the faceplate (e.g., McCoy, Roto, etc.).