Building a Wardrobe Interior System (Compatible with IKEA Pax): Clothes Rails & Drawers

November 2, 2025

A functional interior system for wardrobes requires the exact matching of runner lengths, load capacities, and fittings to the carcass's standardised System 32.

When planning or expanding modular wardrobe systems that are compatible with standard dimensions such as IKEA Pax, technical precision determines overall stability. Whether it is a compact wardrobe with a width of 80 cm or a room-filling structure 3 m to 4 m long for a multi-person household: selecting the right drawer runners and clothes rails follows fixed physical and geometric rules. A wardrobe without a suitable internal system is like a toolbox without compartments – the space exists, but usability is lost in chaos.

This guide explains the technical parameters for interior fittings, hardware dimensions, and how to correctly match runners and rails to specific carcass depths.

Key Purchasing Criteria for Wardrobe Interior Systems

When retrofitting drawers and rails, fittings must match the geometry of the furniture carcass precisely. The following technical specifications are essential to keep in mind.

Carcass Depth and Runner Length

The available internal depth of the wardrobe dictates the maximum length of the drawer runner. Standard wardrobes often have an external depth of 50 cm, 58 cm, or 60 cm. Subtracting the back panel and the front gives the clear internal installation depth. For a wardrobe with an external depth of 58 cm (clear internal depth approx. 560 mm), drawer runners 500 mm are typically used. For shallow hallway wardrobes with an external depth of 35 cm or 38 cm, drawer runners 300 mm are the standard choice. The runner must never be longer than the clear internal depth, otherwise the front will not close flush.

System 32

Modular wardrobes use System 32 for mounting interior fittings. This consists of a continuous line of drill holes in the side panels. The holes have a diameter of 5 mm, and the distance from hole centre to hole centre is exactly 32 mm. The standard setback of the front row of holes from the front edge of the carcass is 37 mm. Hardware designed for this system can be accurately secured with Euro screws (Ø 5 mm) without any need for new drilling.

Load Capacity of Fittings

Load capacity is specified in kilograms (kg) and always refers to a pair (two runners). For lightweight clothing, runners with a 15 kg to 20 kg load rating are sufficient. If heavy winter jumpers or shoes are to be stored, runners rated for 30 kg to 45 kg are required. The load capacity of a clothes rail depends on material thickness and span. A benchmark value for oval steel rails is roughly 15 kg to 20 kg per linear metre.

Types and Options at a Glance

The market provides various mechanical solutions for wardrobe accessories. The chosen mechanism affects both installation effort and daily accessibility.

Drawer Runners: Extension and Mounting Type

Full extension: A full extension runner pulls out 100% from the carcass. This provides unobstructed access right to the back corner of the drawer. Full extension drawer runners are ideal for deep wardrobes.
Partial extension: These runners stop before the drawer is pulled out completely (usually at approx. 75% to 80%). The rear section remains inside the carcass.
Undermount runners: With this system, the runner is mounted concealed beneath the drawer base. The drawer side panels remain free from visible hardware. Undermount drawer runners also offer high lateral stability.

Additional Mechanical Features

Damping: An integrated soft-close mechanism gently cushions the drawer over the final centimetres and pulls it shut silently. Soft-close drawer runners protect the material and prevent slamming.
Push-to-open: A light press on a handleless front pops the drawer open. Important for planning: soft-close and push-to-open are opposing mechanisms and cannot be combined in the same runner on standard fittings.

Clothes Rails

Longitudinal rail: The standard steel tube (mostly oval, 30 x 15 mm) running parallel to the back wall. Requires a clear carcass depth of at least 500 mm so that coat hangers do not catch on the door.
Pull-out rail: For shallow wardrobes (e.g. 35 cm deep), a pull-out clothes rail is installed underneath a shelf. Clothing hangs frontally facing the user and is pulled forward as needed.

Which System for Which Scenario? (Decision Guide)

The layout of the interior fittings depends primarily on carcass dimensions and intended usage.

When the wardrobe is 58 cm to 60 cm deep: Utilise the full depth. Fit complete drawer systems or wooden drawers with 500 mm long runners. A full extension runner is strongly recommended here, as a partial extension runner makes the rear area difficult to reach at this depth. A classic longitudinal clothes rail is ideal for hanging clothes.

When the wardrobe is only 35 cm to 40 cm deep: Standard coat hangers (approx. 45 cm wide) will clash with the doors here. Fit a pull-out clothes rail instead. For drawers, choose short runners (e.g. 300 mm or 350 mm). Because the drawers are shallow anyway, a partial extension runner is often technically sufficient and saves installation space.

When the wardrobe is 180 cm or 201 cm high: At a height of 180 cm, there is limited room for double hanging tiers. Plan 3 to 4 drawers (height approx. 200 mm each) in the lower section, with a clothes rail above for shirts and jackets.

When the wardrobe is 236 cm high: Here, you can install two clothes rails one above the other (spaced approx. 100 cm to 110 cm apart) to double the hanging space for shorter garments. Alternatively, use the lower third for intensive drawer storage with up to 6 stacked drawers.

Installation and Fitting Notes

Retrofitting interior systems requires accurate workmanship. Deviations of even a millimetre can cause drawers to jam or runners to seize.

Required tools:

Cordless screwdriver with PZ or TX bits
Crosshead screwdriver (for fine adjustments)
Spirit level or set square
Tape measure (with mm markings)

Fitting steps for drawer runners in System 32:

Determine position: Count the holes in the drilled hole line from the bottom to ensure exactly the same height on both sides.
Position the runner: Place the carcass section of the runner into position. The front mounting hole of the runner is fastened in the first hole of the line (37 mm from the front edge).
Screw in place: Use Euro screws (5 x 13 mm), as these are designed specifically for 5 mm drill holes and provide a secure hold. Alternatively, if no pre-drilled holes exist, use chipboard screws (3.5 x 15 mm or 4 x 16 mm) and screw directly into the timber.
Insert the drawer: Mount the drawer onto the extended runners and lock it in place (via click mechanism or screws, depending on the system).
Adjustment: Modern undermount runners feature adjustment wheels for tilt and height on the front. Adjust these until the reveal gaps of the closed fronts are uniform (recommended gap size: 2 mm to 3 mm).

FAQ – Frequently Asked Questions About Wardrobe Interior Systems

What runner length do I need for an IKEA Pax wardrobe (58 cm depth)? For the deep Pax carcass (58 cm external dimension, approx. 56 cm internal dimension), you need drawer runners with a nominal length of 500 mm or 530 mm. Longer runners will hit the back panel.

Can I combine soft-close and push-to-open? No, on standard mechanical fittings these functions are mutually exclusive. Soft-close actively pulls the drawer shut over the final centimetres, whereas push-to-open relies on spring tension to push the drawer open when pressed.

How much clearance is needed between two drawers in a wardrobe? The clearance depends on the drawer front height plus the desired reveal gap. Usually, a gap of 2 mm to 3 mm between fronts is planned. For handleless systems, slightly more room may be necessary to allow the front to be pressed in to trigger the push mechanism.

Which screws should I use for clothes rail brackets? When fixing the rail bracket into the pre-drilled 32 mm hole line, use Euro screws (Ø 5 mm). If you need to position the bracket freely on the panel surface, use chipboard screws (Ø 3.5 mm or 4 mm, maximum length 15 mm for 18 mm thick side panels to prevent breaking through the board).

Why is my full extension runner sticking after installation? This is usually caused by an installation misalignment. If the internal width between carcass sides does not match the drawer width precisely (tolerance on ball-bearing runners is often just +/- 1 mm), the system will bind. Runners that are not installed perfectly level will also run unevenly.

Related Products & Categories

For professional installation or repairs to your wardrobe interior system, you will find the appropriate technical hardware in our specialist categories. Choose your fittings strictly according to your measured carcass depths and required load capacities: