Glossary

Clear opening

The width of the gap a gate has to cover, measured between the inside faces of the two posts. The first number you take for sizing any gate.

The clear opening is the gap you need to close, measured between the inside faces of the two posts at their closest point. It is the first number you take on site.

Do not measure post-centre to post-centre, and do not trust a number off a plan. Measure the real gap, because posts are rarely dead straight or perfectly upright.

A gate is usually built a bit wider than the clear opening so it laps over the posts or fence when closed and leaves no gap. In CAD60 you type the clear opening width, set an overlap allowance on each side, and it works out the full gate width for you.

Related terms

Overlap allowanceExtra width added to each side of a sliding gate so the closed gate laps over the post or fence and leaves no gap. Usually 50 to 150 mm per side.
Sliding gateA gate that slides sideways to open, instead of swinging out. Picked when there is no room out front for a gate to swing.
SetoutMarking where the posts, gates, and panels will go on the real ground before any digging starts. The last chance to catch a measuring mistake.
Datum lineA line that is perfectly flat and level. You stretch it across an opening and measure from it, so every measurement starts from the same place.

Used in these CAD60 models

Battened Sliding GateParametric sliding gate with a rectangular hollow-tube frame and vertical battens face-fixed to the front. Supports optional tail extension for motor automation and optional L-piece top rail.
Slatted Sliding GateParametric sliding gate with a rectangular hollow-tube frame and evenly-distributed slats. Supports vertical or horizontal slat orientation, optional tail extension for motor automation, and optional L-piece top rail.