Premium Steel Doors Manufactured in Britain
Premium Steel Doors Manufactured in Britain 
Steeldor thermal was developed to comply with door efficiency targets stipulated by the government in Part L of the updated Building Regulations. The leaf has an insulated, internal Rockwool core enabling it to achieve a U-value as low as 1.5 W/m2K, compliant with the guidance of 1.6 for new dwellings and 1.8 for new commercial buildings in England.
The UK government has committed to reducing carbon emissions and meeting its target of net-zero emissions by 2050. In line with this, several changes have been made to the building regulations to improve the energy efficiency of buildings. One such change is to Part L of the building regulations, which sets minimum standards for the U-values required for a steel door.
Fast quotes
Easy fit doors
10-15 day lead time*
Steel door experts
Single - up to 2.96m
Double - up to 2.96m
Single - up to 1.4m
Double - up to 2.7m
44mm deep leaf skin
EN1026:2000 to class 4 – 600Pa (113kmh) test pressure
EN1027:2000 to 150Pa for outward opening and 100Pa for inward
EN12211:2000 to 1200Pa (Class A3) 98 mph
Single - As low as 1.6 W/m2K
Double - As low as 1.5 W/m2K
BS 6375: Part 1: 2009 (test to EN1026:2000, EN1027:2000, EN12211:2000) to 1200 exposure rating
Up to 39dB rating.
Frames
Manufactured from lightweight, high tensile 1.5 mm thick ‘Rustec’ steel. Adjust 2-Fit side expander system that offers up to 12mm expansion to the structural opening.
Leaf
44mm door leaf thickness, fitted with a flush lipped astragal for added security. Comprising of 2 x 1.2mm ‘Rustec’ steel sheets, the leaf is internally bonded with a dutch fold stitch welded system providing greater stability and protection against de-lamination. Rockwool insulated core.
Door ironmongery
BS 7352 Grade 13 stainless steel, twin bearing template drilled butt hinges with integral high-security dog bolts are fitted as standard with CE marking. Other hardware on request.
Finish
Supplied inclusive of a powder-coated finish in a standard colour. Full range of RAL and BS colours available.
Options and upgrades
Available as PAS 24: 2016.
Single Door Installation
This video contains detailed, step-by-step instructions for the safe installation of a Strongdor Steeldor single door-set. Please pay particular attention to the safety instructions.
Double Door Installation
This video contains detailed, step-by-step instructions for the safe installation of a Strongdor Steeldor double door-set. Please pay particular attention to the safety instructions.
Speak to an expert now
01524 727000 Personnel Steel Doors & Emergency Exit Steel Doors
It is the customer’s responsibility to ensure all details within the sales quotation / sales order meet the exact specification and / or original enquiry and are compliant with current building regulations including location and method of installation.
We are here to help and advise only and cannot accept responsibility for discrepancies after the order is confirmed.
Strongdor Terms and Conditions
No, Strongdor are a supply only manufacturer and therefore unfortunately don't offer site surveys or installation. However we can recommend local installers in your area from our Doorfit Network, who will be happy to help.
Complete our quotation request form, mention you are looking for installation and we will put you in touch!
Purchase steel doors regularly? Speak to one of our account managers and request to set up an account today.
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