Quality Windows, Doors, Bi-Fold Doors and Conservatories to the Trade

Highseal Manufacturing Company

We manufacture beautiful, strong and "Secured by Design" WarmCore Aluminium folding sliding doors in a range of sizes, from 1 to 7 sashes.

The profile contains a hidden orange thermal core which makes the doors 25% more thermally efficient than traditional Aluminum systems.  

Triple glazing provides ultimate thermal performance.  

The doors stack neatly, with inward or outward opening, and can be supplied up to 6m wide.  

This innovative design comes with a choice of sash options and handle finishes, and different colours, styles and configuration options to help you choose the perfect warm, secure and beautiful WarmCore door for your home.  

Each set of bi-fold doors comes complete with a 10-year product guarantee, supported by the ERA Five Star security guarantee.  

Bi-fold doors from Highseal Manufacturing Company

The flexible system enables you to split the door sashes in whichever way suits your home.  You can have all the bi-fold doors sashes fold to the right or to the left or have them split in any combination of your choice.  A popular configuration is to have a single door at one end called a traffic door; this allows you to leave the majority of the door sashes locked in place whilst using the single door for everyday use.  Another option is to have the door sashes meet in the middle or at one end; this could then be used as a set of French doors.  The flexibility enables you to use your bi-fold in a way that suits your lifestyle, for example when entertaining. 

Attention has been paid to how the doors look when stacked open, something that is often overlooked on traditional door systems.  When the doors are in the open position, all the sashes are neatly stacked and aligned with each other using discreet magnets to remain perfectly parallel; this prevents sashes from clattering when in the open position. They are available in a choice of 4 hard-wearing powder coated finishes, and you can choose a different colour for the interior and the exterior at no extra cost.  There is also a choice of 4 external Aluminium designs for the door sashes, 4 threshold options and a choice of 3 beautiful handle finishes. 

Bi-fold doors from Highseal Manufacturing Company

WarmCore door handles are gracefully curved around door sashes when open, tucking into the glass reveal and allowing the door sashes to fold perfectly flat, and are made to last for at least 10 years.  The anodised finishes are ideal for use in coastal or exposed locations and are available in 3 hard-wearing finishes.  Choose the perfect match to complement your door - Satin Silver, Brushed Graphite or Matt Black. 

Highseal Manufacturing Company Windows and Doors
Highseal Manufacturing Company Windows and Doors
Highseal Manufacturing Company Windows and Doors

WarmCore powder coated colours available: Anthracite Grey, Heritage Cream, Jet Black or Pure White.  You can select a colour for each side of your door at no extra cost. As demonstrated, our example shows a Pure White exterior and Jet Black interior.  What you choose relies only on your your creativity and this defines the architectural style of your home.  With a choice of 4 external Aluminium door sash designs to help personalise your door or to compliment the style of your existing windows.  Sash styles available: Chamfered, Pencil Round, Decorative and Square. 

B-fold doors from Highseal Manufacturing Company

WarmCore comes with a range of threshold options including ultra low Part M compliant Aluminium thresholds that help avoid trip hazards; alternatively you could have a step down from your door opening.  There is also a choice of sills available (to view the threshold options please click on the PDF file).  The options available: outer frame, 120mm integrated sill, 150mm sill or low Aluminium threshold. 

The WarmCore door combination ranges from a single or French door, from 2-door to 7-door bi-fold.  

The unique 5-point lock is designed to run the full length of the door sash to the high strength hinges and rollers.  Each element of the WarmCore door combines to ensure optimum security.  The WarmCore's Aluminium construction, custom-made roller assemblies sitting deep within the top and bottom tracks, and extruded aluminium hinges, make the doors inherently strong and secure.  Added security features, such as integral dog bolts, bind the door sashes together when closed protecting them against forced entry.  A custom-designed door lock, not available on any other door system, uses a 5-point locking system with 3 opposed hook locks and twin shoot bolts, that engage fully into the Aluminium top and bottom tracks helping to keep you and your family safe and secure. Every WarmCore is independently certified to PAS24:2012, the benchmark in enhanced security performance requirements for doorsets and windows in the UK.  You can upgrade to laminate glass for extra peace of mind. 

Highseal Manufacturing Company Bi-Folding Doors

Glass options available; standard low-e glass, celsius glass, triple glazed or laminated. Triple-glazing provides 75% more thermal performance than standard double-glazed Aluminium bi-folds. Choosing 44mm triple-glazing increases the whole door U-Value rating from 1.4 to 1.0, compared to the standard 28mm double-glazing. Celsius glass is a high performance and easy clean glass, available as an optional upgrade.


This high performance glass utilises a low-e and solar control coating with an Argon filled cavity to limit the amount of UV and heat that passes through the glazed unit, giving the ultimate in thermal control whatever the weather. Easy clean technology has also been added to reduce maintenance requirements. The coating lasts the lifetime of the glass; dirt and grime simply wash off with normal rain rather than sticking to the glass.  This also provides 58% Heat reflection and 73% UV protection. 

Fixings: Stainless Steel to resist corrosion and tough extruded Aluminium hinges. Quad-wheeled track rollers are precision engineered to perform perfectly every time.  High-strength rollers have a 200 Kgs load capacity but WarmCore still ensures a smooth operation.  Tested over 50,000 cycles, the precision components ensure years of trouble-free and reliable operation. The 10-year guarantee covers materials, surface finish and operation. Triple weather-sealing on all sash interlocks ensures exceptional weather performance, keeping drafts and wind-driven rain outside. Run-through rubber gaskets create continuous weather-seals helping WarmCore to comfortably exceed the requirements of BS6375-1: the classification for weather tightness on windows and doors.

  • Max door width: 600mm

  • Max door height: 2400mm

  • Max sash width: 1000mm

  • Max load per sah:100kg

  • Frame and sash sightline: 129mm

  • Low threshol and sash sightline: 109mm

  • Sash to sash sightline: 156mm 


Fair Share Group Limited - Highsealfsg

26 Hebden Road, Scunthorpe, North Lincolnshire, DN15 8DT United Kingdom

Phone Us

+44 (0)1724  859  326

Send a Fax

+44 (0)1724  845  576