Aluminium systems

Sliding Window And Door Panel Planner

A sliding window never opens as wide as it looks. On a two track window, one panel slides behind the other, so at best you get half the opening, less the frame and the overlap. People discover this after installation, usually when a sofa will not fit through what was supposed to be a wide opening.

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This planner shows the split before anything is ordered. Enter the opening, choose two or three tracks, and it draws the panels and works out the clear opening you will actually have.

What This Tool Does

It calculates panel widths from the opening, the frame deduction and the sash overlap, draws an elevation of the panels, and reports the theoretical clear opening both in millimetres and as a percentage of the hole in the wall.

Who It Is For

Homeowners choosing between two track and three track.
Anyone planning a large opening where panel size starts to matter structurally.
Fabricators showing a customer what a given configuration will look like.

How To Use It

Measure the opening, width and height.
Choose two track or three track.
Enter the sash overlap at the meeting stile and the outer frame deduction per side. Both come from the profile system catalogue, so ask your fabricator rather than guessing.
Tick the mesh box if one panel will be a mosquito mesh.
Press the button to see the panels and the clear opening.

Inputs And Units Explained

Opening width and height — the masonry opening.
Tracks — two gives two panels, three gives three narrower ones and a wider clear opening.
Sash overlap — how much the panels overlap where they meet. Usually 40 to 60 mm, but it is system specific.
Outer frame deduction per side — how much the frame takes off the glass area on each side.

How The Calculation Works

The inner width is the opening minus the frame deduction on both sides. Panels are sized so that the number of panels, with the overlaps counted once each, fills that inner width: panel width is the inner width plus the overlaps, divided by the number of panels. The clear opening is then the inner width minus the panels that remain in the way when the others are slid across.

These are geometric figures from the numbers you entered. Real systems have interlocks, drainage and tolerances that shift the result slightly, which is why the page ends with the questions to put to your fabricator rather than a claim of precision.

Worked Example

A 6 by 4 foot opening with a two track system, a 50 mm overlap and a 45 mm frame deduction per side.

Input or result	Value
Opening	6 ft (1,829 mm) wide
Inner width after frame	1,739 mm
Panels	2 panels of about 894 mm each
Theoretical clear opening	about 845 mm, roughly 46 per cent of the opening

Less than half the opening, which is normal for two track and is exactly the thing worth knowing in advance. A three track system in the same hole gives three narrower panels and a noticeably wider clear opening.

Features And Benefits

The clear opening calculated rather than assumed.
A panel elevation you can show the fabricator.
An immediate two track against three track comparison.
A list of system questions that catch the common installation problems.

Assumptions And Accuracy Limits

Overlaps and deductions are brand specific. Without the catalogue figures the result is indicative.
The tool does not check whether a panel is too large for the profile, which is a real limit on big sliding units.
Roller capacity and glass weight are not assessed. Large panels with thick glass get heavy.

Common Mistakes To Avoid

Expecting a two track window to open fully. It never does. Plan for about half.
Guessing the overlap. Ask for the system figures; a 20 mm error across three panels is visible.
Ordering very wide panels without checking the profile. Heavy panels sag and stick, and that is a specification problem, not an installation one.

Sliding Aluminium Windows And Doors In Pakistani Homes

Sliding windows and doors are common in lounges, bedrooms and balconies because they save swing space. The part people get wrong is the panel arithmetic: two sliding panels do not each cover half the opening, because they overlap in the middle, and a three track window leaves part of the opening permanently closed.

Enter the opening width and height and the number of panels, and the planner shows the width of each panel and how much of the opening you can actually open for ventilation.

Frequently Asked Questions

How much does a 2 track sliding window actually open?

A little under half the opening, once the frame and the overlap are taken off. The tool works out the exact figure from your measurements and your system numbers.

Is 3 track better than 2 track?

It gives a wider clear opening and more ventilation options, at a higher price and with narrower individual panels. For a wide opening where you want most of it open, three track is usually worth it.

Where do I get the overlap and frame deduction figures?

From the fabricator or the profile system catalogue. They are specific to the brand and series, and the honest answer is that no calculator can know them for your window.

How much of a sliding window actually opens?

In a two panel window about half the width opens, in a three panel window about a third. The planner shows the open area for your layout.

What is the difference between a sliding and a casement window?

A sliding window glides sideways on a track, while a casement swings outwards or inwards on hinges. Sliding suits tight spaces, casement gives a fuller opening.

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Get A Measured Quotation

Panel splits and clear openings are worth agreeing before the profile is cut, because they cannot be changed afterwards. Ramzan Steel Works will confirm the real deductions for the system being used and show you what the opening will actually give you.