DIY Installation Guide

How to Measure and Specify Your Insulated Roller Garage Door

When you're fitting a new insulated roller garage door yourself, getting the dimensions right is the most important step. Because all of our SeceuroGlide, Samson, GDO, and Gliderol roller doors are made to measure, you can order a door that perfectly fits your specific garage opening.

One of the main practical benefits of a roller door is the flexibility in how you fit it. You can install them behind the brickwork (internally), directly between the brickwork reveals, or even on the outside of the garage.

We've put this guide together to walk you through exactly what measurements you need for each installation type, so you get a perfect fit the first time.

* Please note: The diagram below shows a typical aluminium insulated roller door fitted with an optional full hood cover. For Hormann Rollmatic and Garador insulated roller doors, measuring is based on the daylight opening sizes, so please refer to those specific product pages.

Understanding Your Width Dimensions

When buying a double-skinned, aluminium insulated roller door, the measurement you use to order is the Overall Guide Width. This is your drive-through width (the physical hole in the wall) PLUS the width of the two aluminium side guides.

For example: If your brickwork opening is 2500mm wide and you are fitting the door behind the brickwork with standard 75mm guides, your Ordering Width is 2650mm (2500mm + 75mm + 75mm). If you need the larger 90mm guides, your Ordering Width becomes 2680mm. Always double-check your chosen guide sizes when working out your final order dimensions.

Guide Width Options (SeceuroGlide 77mm Model Examples)

75mm Guide: The standard size for most 77mm insulated roller doors up to 3000mm wide.

90mm Guide: Supplied as standard for doors 3001mm or wider. These provide a deeper channel for the curtain to run in, giving the door much better stability against the wind. You can also request these as an optional extra on smaller doors if your garage is in a particularly exposed or draughty location.

Understanding Your Height Dimensions

The ordering height for a roller door is the Guide Height. This is the exact height of the vertical guide rails, running from the floor up to the bottom of the endplates (the heavy-duty brackets that hold the rolled-up curtain).

The total physical height of the complete unit will be your Guide Height PLUS the height of the endplate. Endplate sizes vary between manufacturers and usually get larger as the door gets taller, simply because a taller door creates a thicker curtain roll.

The diagram above shows the three different endplate sizes for the SeceuroGlide range, with the Compact 55mm roller door requiring the smallest headroom.

* Important note on hangdown: When a roller garage door is fully open, the bottom slat will still hang down into the opening by about 55mm. This means your actual drive-through height will be your Guide Height minus 55mm. If you drive a tall 4x4 or a van, please make sure you allow enough tolerance for this clearance.

Choosing Your Installation Position

1. Internal Face Fitting (Recommended)

Fitting the door to the inside face of the garage wall is the most common and practical approach. It keeps the guide rails and the curtain roll entirely hidden from the outside, giving you a clean visual finish from the driveway. Because the mechanical parts are tucked away behind the brickwork, this fitting method also leaves you with the maximum possible drive-through width and height.

2. In-Between Fitting

If you don't have enough headroom or side room inside, you can fit the door directly between the brickwork opening. You need to be much more precise with your measurements here. Always measure the width at the top, middle, and bottom of the opening, and use the smallest dimension.

* Always remember to allow for some fitting tolerance when ordering. The factory manufactures these doors to the exact millimetre dimensions you provide. You must deduct your own fitting tolerance (usually around 5mm to 10mm overall) from your smallest brickwork measurement. If you order the exact tight size of the opening, the frame will likely be too tight to physically fit into the brickwork.

If your brickwork isn't perfectly plumb, you might need to use packers behind the guides and endplates to square things up. Keep in mind that when fitting this way, the vertical guides and the curtain roll will be visible from the outside, so it's worth thinking about whether you want their colour to match or contrast with the main door panel.

3. External Face Fitting

Sometimes the only option is to fit the door to the outside face of the garage. If you are doing this, you must order the door with a full hood cover to protect the curtain, guides, and endplates from the weather. The control box receiver isn't waterproof, so that will still need to be wired up internally or placed inside a separate weatherproof housing.

* A crucial note on external fitting: Because the door rolls up, an externally fitted door means the 'inside' face of the curtain is what is displayed to the street. For this reason, we strongly advise against choosing laminate woodgrain finishes for external fits, as the back of the slats is usually just a flat painted colour. Always double-check the finish specifications with us if you're planning an external installation.