Measuring guide — Cross-section
A = exterior height · B = opening width · C = interior height
From the exterior ground up to the bottom of the spirit level
For information only — clear width between the two frames
From the interior ground up to the bottom of the spirit level
Determines the ramp width: < 36″ → 32″ ramp · ≥ 36″ → 36″ ramp
Measurements taken with a spirit level resting on the patio door tracks, as shown above.
