GDO Pro 20mm Horizontal Rib with Square Porthole Window (32 Colour Options) garage door Steel GDO

GDO Pro 20mm Horizontal Rib Side Hinged Doors with Square Porthole Windows

The GDO Pro 20mm Horizontal Rib with square porthole windows combines contemporary styling with the thermal and security benefits of a modern insulated doorset. Moving away from standard steel designs, this premium UK manufactured side hinged garage door features a striking vertical arrangement of four square windows, offering a unique architectural finish while welcoming natural light into your garage.

Distinctive Horizontal Rib and Porthole Design

The aesthetic of this door is defined by its clean, evenly spaced horizontal ribbed panels, which visually widen the appearance of the garage opening. This is perfectly contrasted by a modern vertical column of four square porthole windows integrated into the active door leaf. This contemporary window arrangement is ideal for allowing daylight into the garage without compromising privacy or security. The heavy duty steel panels are finished in a highly durable stipple effect powder coating, available in 32 standard colours, including white as standard. For maximum versatility, custom RAL colours are available upon request to perfectly match your home's exterior.

Advanced Double Skinned Insulation

Unlike basic single skin steel doors, the Pro 20mm doorset is engineered with an advanced 20mm deep insulated core. Twin steel outer skins are bonded to a central thermal core, providing exceptional structural rigidity while significantly reducing heat loss and draughts. This thermal efficiency makes the door an excellent investment for integral garages, home workshops, gyms, or any space that requires a comfortable, well regulated internal temperature all year round.

High Security Operation

Security is a primary focus of the Pro 20mm range. The active door leaf features a standard lever handle operating a reliable deadlock, while the inactive leaf is held firmly in place by concealed shoot bolts positioned at the top and bottom of the panel. For taller double leaf doors (over 1600mm high), an optional three point security locking upgrade is available to provide maximum resistance against forced entry.

Pre-Assembled for Effortless Installation

Designed to eliminate the complexity of on site assembly, the GDO Pro 20mm is delivered as a complete, pre-assembled unit. Both insulated door panels are factory hung within a rigid box section aluminium sub frame. All essential hardware, including handles and colour matched 3-way adjustable hinges, are pre-fitted at the factory. Installers simply secure the outer frame and the standard included floor threshold into the structural opening, drastically reducing fitting time and ensuring perfect panel alignment from the start.

Key Features and Benefits

• Unique Window Design: Four square porthole windows arranged vertically in the active leaf for a striking modern aesthetic and natural light.
• Made to Measure: Custom manufactured to your exact opening dimensions at no extra cost.
• 20mm Insulated Panels: Double skinned steel bonded to a thermal core for superior strength and temperature regulation.
• Pre Assembled Frame: Factory fitted within an aluminium sub frame for the easiest possible on site installation.
• Security As Standard: Concealed shoot bolts, robust deadlocks, and an optional three point locking upgrade for taller doors.
• 32 Colour Options: Durable powder coated stipple finishes, with special RAL colours available on request.
• Flexible Configurations: 50:50 or 1/3-2/3 split designs with your choice of left or right active leaf opening (outward opening standard, inward on request).
• UK Manufactured: Built to high engineering standards in the UK, complete with a standard floor threshold.

When you are ready to order, simply choose the 'up to' size that covers your opening, and then enter your exact structural measurements into the ordering fields. From there, you can configure your door using the options provided. If you have any special requirements, such as needing the doors to open inwards, or if you just want to check the latest pricing and specifications, please feel free to email or call our team.

Factory Fitted Sub Frame
To ensure the easiest possible installation, your GDO Pro 20 doorset is delivered fully assembled with the aluminium fixing sub frame factory fitted as standard. This all in one construction guarantees accurate panel alignment straight out of the factory.

3 Point Locking
For an added level of security, a three point locking system featuring twin hood locks is available as an optional upgrade.
Please note: Minimum height over frame required is 1600mm.

Hinges
All heavy duty hinges come colour matched to your chosen door finish and are fully adjustable in three directions, allowing for fine tuning and perfect alignment of the door leaves on site.

Seals
Double seals fitted to both the door leaf and the frame help to protect your garage interior against the weather, while effectively limiting dust and debris from entering the space.

Handle Options
Customise the look of your doorset by selecting from our premium handle finishes. Options are available in Bronze effect (dark brown appearance), Gold effect, or Satin effect to perfectly complement your chosen door colour.

Window Placement and Glazing Choice
The distinctive square porthole windows are typically arranged vertically within the active door leaf. However, when placing your order, you can specify exactly which leaf you would prefer the windows to be positioned in to best suit your property's exterior. Additionally, you can choose between clear glazing for maximum light transmission or stippled glazing for increased privacy.

Door Split Configurations
To perfectly match your driveway and daily access needs, this doorset is available in two distinct configurations: a symmetrical 50:50 split, or an asymmetrical 1/3 and 2/3 split. You can also specify whether you require the active (primary opening) leaf to be on the left or the right.

Matching Pedestrian Side Doors
If your garage features a separate side entrance, we offer matching pedestrian doors built to the exact same high quality, double skinned insulated specification as your main garage doors. Available in widths up to 1320mm and heights up to 2340mm, these side doors feature the same vertical rib design, handle options, and robust deadlock arrangement, ensuring a perfectly consistent aesthetic across your property.

Door Stays
Friction door stays are now fitted as standard at no extra charge, preventing the doors from blowing shut in the wind.

Colour Options
Personalise your garage door with a choice of 32 colour options. The paint finish features a highly durable powder coat ripple texture, providing an attractive appearance alongside excellent resilience against the British weather.

Choose from the classic low gloss solid colours below:

STANDARD FOC COLOURS:
White RAL9016
Black RAL9005
Grey RAL7016

PREMIUM COLOURS:
Signal Grey RAL7004
Dusty Grey RAL7037
Traffic Grey RAL7042
Light Grey RAL7035
Window Grey RAL7040
Basalt Grey RAL7012
Pebble Grey RAL7032
Iron Grey RAL7011
Slate Grey RAL7015
Graphite Grey RAL7024
Agate Grey RAL7038
Black Grey RAL7021
Steel Blue RAL5011
Cobalt Blue RAL5013
Sky Blue RAL5015
Gentian Blue RAL5010
Signal Blue RAL5005
Light Blue RAL5012
Moss Green RAL6005
Fir Green RAL6009
Chartwell Green BS14 C 35
Ruby Red RAL3003
Traffic Red RAL3020
Chocolate Brown RAL8017
Clay Brown RAL8003
Mahogany Brown RAL8016
Light Ivory RAL1015
Cream RAL9001
Traffic Yellow RAL1023

The GDO Pro 20 insulated side hinged garage door combines a striking contemporary aesthetic with modern engineering, delivering exceptional performance for everyday use. Proudly made in the UK, this double skinned doorset offers superb thermal efficiency and robust security.

Square Porthole Window Design
This specific doorset features a striking vertical arrangement of four square porthole windows. The windows are double glazed using a durable, scratch resistant polymer material rather than standard glass, ensuring maximum safety and weight efficiency. The window frames are colour matched to your chosen door finish to maintain a seamless, premium appearance.

3 Point Locking
For an added level of security, three point locking with twin hood locks is available as an option.
Minimum height over frame required is 1600mm.

Hinges
All hinges come colour matched to the door panel and are fully adjustable in three directions for ease of alignment of the leaves during installation.

Seals
Double seals fitted to both the door leaf and the frame help protect your garage interior against the weather and effectively limit dust and debris from entering the space.

Handle Options
Customise the look of your doorset by selecting from our premium handle finishes. Options are available in Bronze effect (dark brown appearance), Gold effect, or Satin effect to perfectly complement your chosen door colour.

Door Stays
Friction door stays are now fitted as standard at no extra charge, preventing the doors from blowing shut in the wind.

Colour Options
Available in a choice of 32 colour options, the paint finish is a highly durable powder coat ripple texture giving an attractive appearance alongside excellent resilience.

Choose from the classic low gloss solid colours below:

STANDARD FOC COLOURS:
White RAL9016
Black RAL9005
Grey RAL7016

PREMIUM COLOURS:
Signal Grey RAL7004
Dusty Grey RAL7037
Traffic Grey RAL7042
Light Grey RAL7035
Window Grey RAL7040
Basalt Grey RAL7012
Pebble Grey RAL7032
Iron Grey RAL7011
Slate Grey RAL7015
Graphite Grey RAL7024
Agate Grey RAL7038
Black Grey RAL7021
Steel Blue RAL5011
Cobalt Blue RAL5013
Sky Blue RAL5015
Gentian Blue RAL5010
Signal Blue RAL5005
Light Blue RAL5012
Moss Green RAL6005
Fir Green RAL6009
Chartwell Green BS14 C 35
Ruby Red RAL3003
Traffic Red RAL3020
Chocolate Brown RAL8017
Clay Brown RAL8003
Mahogany Brown RAL8016
Light Ivory RAL1015
Cream RAL9001
Traffic Yellow RAL1023

One of the biggest advantages of the GDO Pro 20 insulated side hinged garage door is that it is delivered fully pre assembled. The insulated door leaves come factory hung within their heavy duty aluminium sub frame, eliminating the need for complex assembly on site. This "all in one" approach significantly reduces installation time and ensures factory accurate tolerances from the start.

While full, detailed manufacturer fitting instructions are provided with the door, the standard installation process follows these key steps:

1. Preparation and Checking

Before removing your old garage door, carefully measure your new GDO Pro 20 doorset and check it against your structural opening to ensure it will fit. Make sure the floor where the threshold will sit is solid and completely level; an uneven floor can cause the doors to catch or prevent the weather seals from working effectively.

2. Positioning the Doorset

Because the doors and frame are pre-assembled, they should be offered into the structural opening as one complete unit. Keep the door leaves closed and locked during this stage to keep the frame rigid. Use plastic packers or timber wedges between the aluminium frame and the brickwork to hold the doorset securely in place. Use a high quality spirit level to ensure the frame is perfectly plumb, square, and level.

3. Fixing the Frame

Once you are completely satisfied that the frame is perfectly upright and square, drill through the aluminium fixing sub frame and into the structural opening. Secure the frame using appropriate masonry frame fixings (not supplied). It is important not to over tighten the fixings, as this can bow the aluminium frame and pinch the door leaves.

4. Securing the Threshold

The doorset features a built in threshold that must be firmly fixed to the floor. Ensure a line of sealant is applied beneath the threshold before final fixing to prevent water from tracking underneath into the garage.

5. Testing and Final Adjustments

Once the frame is fully secured, unlock and open the door leaves to check their operation. They should swing smoothly without catching. If slight adjustments are needed due to the opening being slightly out of square, the GDO Pro 20 features heavy duty 3-way adjustable hinges. These allow you to finely tune the position of the door leaves in three directions for a perfect, even gap and smooth lock engagement.

6. Perimeter Sealing

Finally, once the door is operating perfectly, apply a high quality exterior silicone sealant around the entire perimeter gap between the aluminium frame and the brickwork to ensure the installation is completely weather tight.

Please note: We always recommend downloading and reading the full official installation manual prior to beginning work.

Installation instructions can be found here

GDO Pro 20 Warranty & Guarantee

The GDO Pro 20 side hinged garage door is manufactured in the UK to exacting engineering standards. To provide you with complete peace of mind, your doorset is backed by a comprehensive manufacturer's warranty. To ensure the validity of these guarantees, the door must be installed, operated, and maintained in accordance with the supplied manufacturer instructions.

10-Year Safe and Reliable Operation

The main structure of the GDO Pro 20 door is covered by a 10-year warranty ensuring safe and reliable operation. This provides long-term confidence in the core structural integrity and safety of your garage doorset.

2-Year Hardware and Component Guarantee

A 2-year warranty is provided on all moving and mechanical parts under normal daily use (defined by the manufacturer as up to 5 open/close operations per day). This comprehensive cover includes all primary hardware such as hinges, locking mechanisms, shoot bolts, and handles.

2-Year Factory Paint Finish

The factory-applied powder coat colour finishes are covered by a 2-year warranty against primary paint failure. Please note: As is standard with steel door manufacturing, the rolling and pressing process may cause slight natural distortion which can become apparent under certain lighting, and minor cosmetic blemishes are considered normal. The internal rear face of the door is not designed to have the exact same uniform cosmetic finish as the exterior.

Coastal and Estuary Exclusions

Please be aware that any steel doors fitted within 250 metres of the coastline (where the beach ends and the land begins) or directly adjacent to an inland estuary are strictly exempt from the paint finish warranty due to the highly corrosive saline environment.

Key Warranty Conditions and Exclusions

• Inspection upon Delivery: Goods must be carefully inspected upon arrival. Any transport damage or missing items must be reported within 48 hours of receipt. By proceeding to install the garage door, you acknowledge and accept its visual condition; no claims for cosmetic damage can be accepted once the item has been installed.
• General Maintenance: The door panel must be kept clean and free from impact damage. Any accidental areas of paint damage must be dressed with touch-up paint as soon as possible to prevent corrosion. Regular cleaning and light lubrication of the moving parts is required.
• Warranty Invalidation: Improper installation, structural modifications, repairs by non-qualified individuals, or damage caused by severe external influences (such as fire, flooding, alkaline solutions, bird droppings, or abnormal atmospheric pollution) will completely invalidate the warranty.

Always remember to allow for some fitting tolerance when ordering. In a perfect world we would recommend about 10mm all round, meaning you measure the width and height and then take 10mm off the smallest dimensions all round and this gives the Ordering Sizes. In real world apertures the floor is often not level and the aperture not totally square so please make sure you allow enough tolerance to cater for any out of square dimensions.

Minimum & Maximum Ordering Sizes