Rebated Double French Door Offset Calculations: Compensating for Step Overlap
Engineering Overview: Mathematical formula for calculating asymmetrical Euro cylinder offsets on rebated double doors and French entrance doors.
Technical & Engineering Specifications
| Standard | DIN 18252 / BS EN 1303 |
|---|---|
| Door Type | Rebated Double Doors, French Doors |
| Rebate Range | 12 mm to 15 mm standard step |
| Typical Sizing | 30/40 mm, 30/45 mm Asymmetrical |
Rebated Door Centerline Offset
In double French doors, the active door leaf features a 12–15 mm stepped rebate overlapping the slave door leaf.
Calculation Formula
$$\text{Dim A (Inside)} = \frac{\text{Door Thickness}}{2} + \frac{\text{Rebate Depth}}{2} + \text{Plate}$$ $$\text{Dim B (Outside)} = \frac{\text{Door Thickness}}{2} - \frac{\text{Rebate Depth}}{2} + \text{Plate}$$
For a 50 mm door with a 14 mm rebate, the formula specifies 30/40 mm Asymmetric Offset.
Frequently Asked Engineering & Selection Questions
Q1: How do you calculate cylinder length for a rebated French door?
Add half the rebate depth to the inside measurement and subtract half the rebate depth from the outside measurement.