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

Highseal Manufacturing Company

Aluminium tilt and turn window
Aluminium square external sash available on aluminium windows
Pencil round external sash available on aluminium windows

Aluminium windows 25% more thermally efficient

  The aluminium products are strong and secure, they come with multi-point locking and internal beading, and are backed by a 10-year product guarantee.  

Each double-glazed unit has a u-value of 1.3 while the triple-glazed units are 0.8.  Building regulations currently stipulate a u-value of 1.6.  

Our aluminium products come in different colour options: Pure White and Anthracite Grey.  They can be supplied in different colours inside and out.

Non-standard colours available upon request.

Two external sash and outer frame designs: pencil round and square.

Casement Window

Casement windows are available in a "flush sash" for ultimate clean, modern aesthetics.


Just like the aluminium bi-fold doors they are 25% more thermally efficient than the competition.

Tilt and Turn

This design offers style and practicality opening slightly inward in "tilt" mode.


Allows fresh air in securely, or opening fully inwards in "turn" mode to make cleaning and maintenance easier

Warm, Wide Span Bi-Folding Doors for Modern Living

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.  

Also 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.  

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

Aluminium bi-folding doors, anthracetic grey. Highseal manufacturing manufactures aluminium products. Highseal manufactures aluminium products at their factory in Scunthorpe, North Lincolnshire. This alumnium product is available to trade, commercial, DIY and retail.

Technical Data

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.  

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 

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. 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.  

Aluminium hardware and sizes available on Highseal aluminium products

Meet the next generation of Aluminium Patio Doors to meet the growing demands for the patio market. Sleek, Stylish and offering flawless operation. The Warmcore patio door utilities the same innovative full-width thermal core technology like our bi-folding doors.

Aluminium products available, this picture shows the patio layers. Highseal manufacturing manufactures aluminium products. Highseal manufactures aluminium products at their factory in Scunthorpe, North Lincolnshire. This alumnium product is available to trade, commercial, DIY and retail.


Super Smooth 10 Wheel Roller

A unique, high-quality wheel-set with each sash running on 10 self-leveling rollers to give you ultra-smooth reliable performance. 

Innovative Bi-Directional Lock

Designed to our exacting specifications, a bi-directional lock creates a tangible sense of security homeowners love.

Exceptional Thermal Performance

The Warmcore full-width thermal core in the sashes give a double glazed U-value of 1.4 and triple glazed U-value of 1.0 - coupling market-leading thermal performance with the desirability and consumer appeal of aluminium. 

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

 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. 


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