Flat Roof Skylight - Frameless Triple Glazed Rooflight - Flat Roof Window - Roof Lantern - 11 Sizes in Stock

Frameless Flat Roof Skylights - Triple Glazed Rooflights & Flat Roof Windows

Our frameless flat roof skylights bring natural light into extensions, kitchens, stairwells and garden rooms. Each rooflight is a triple glazed, 20mm argon-filled unit with 6mm toughened glass and a U-value of 0.7 W/m²K, giving a sleek, frameless flat roof window that sits on a timber upstand. 11 sizes are in stock in Cardiff for same day dispatch, with next day delivery available. Sizes are listed as external, with the internal opening shown alongside.

Flat Roof Skylight Sizes (External & Internal)

Triple Glazed Rooflight Specification

[Superior Thermal Efficiency] Triple-glazed with a U-value of 0.7 W/m²K, featuring 20mm argon-filled and thermal super spacer technology to minimise heat loss and enhance insulation keeping you nice and warm in the winter and suitably cool in the summer

[Toughened Safety Glass] Constructed with 6mm toughened glass (laminated glass on 2000mm x 1000mm models), ensuring durability, strength, and compliance with BSEN1279 standards

[Natural Light Optimisation Self-cleaning glass]  With 72.6% light transmittance brightens interiors while maintaining clarity and reducing glare, improving overall visibility and ambiance, Great for use in stair wells, ground floor extensions where natural light is limited.

Skylight Timber Upstands & Structural Glazing Tape

OPTIONAL ADD ON TIMBER UPSTAND - PREMADE TO SIZE

Our timber up stands come pre-made from C24 structural grade CLS timber faced with 12mm OSB Sheet, featuring a pre-made 1:40 fall for rain water run off. Simply fix down to your flat roof. weatherproof with your selected roof type ie. EPDM rubber roof and then install the flat roof lantern as per instructions. Typical height 150mm running down to 140mm, 130mm or 125mm depending on the size.. 75mm Thick, hollow allowing you to insulated to achieve Part-L building regs compliance with your own insulation & to face the internal skin with chosen board ie. plasterboard etc.

Also consider our roof lantern structural spacer tape, a must for installation ensuring long term performance and warranty protection. 

Bring natural light into your home with our premium frameless skylights.

Crafted from toughened safety glass with a polished edge finish, these skylights combine strength, style, and performance. Available in a range of standard sizes, they are suitable for both flat and pitched roofs, making them a versatile choice for any property.

Engineered with triple-glazed units, argon-filled cavities, and thermal super spacer technology, our skylights deliver exceptional insulation while maximising light transmission. Designed to enhance interiors with brightness and warmth, they offer a sleek, contemporary solution that’s as efficient as it is elegant. 100mm UV Printed black  border meaning non fading with beveled edges.




Should be installed with 1:40 fall for rain water run off ie. over 1000mm, 25mm fall.







TECHNICAL SPECIFICATIONS

• Internal Size: As Quoted in the Product (200mm smaller then external dimensions, UV printed black border 100mm deep around all 4 sides)
• Glazing: Triple Glazed
  
  Top Layer: 6mm Toughened Safety Glass (PVB Laminated on 2000mm x 1000mm)

Insulated Cavity: 20mm spacer 90% Argon Filled

Middle Layer: 5mm Thermally Toughened

Insulated Cavity: 14mm spacer  90% Argon Filled

Bottom Layer: 6mm Low-E Toughened Glass

• Weight: 52kg/m²
• U-value: 0.72 W/m²K
• Self-Cleaning Glass
• Glass Type: Clear Tint
• Pitch: up to 45 degrees Max
• Thermally Efficient Argon Gas Filled
• Visible Light Transmittance: 73%
• Visible Light Reflectance: 18% in; 15% out
• Solar Energy Reflectance: 28.6%
• Quick and Easy Installation
• Strong, Secure and Durable - Toughened / Laminated

 




ALL ROOF LANTERNS MUST BE CHECKED ON DELIVERY. ANY DAMAGES MUST BE REJECTED AND SENT BACK WITH THE COURIER. CLAIMS WILL NOT BE ACCEPTED FOR DAMAGES AFTER THIS POINT.

Skylight, Rooflight, Flat Roof Window or Roof Lantern?

These are all names for a glazed unit that lets daylight in through a flat roof. A flat glass skylight - also called a rooflight or flat roof window - sits almost flush with the roof for a clean, minimal look, while a traditional roof lantern is pitched and framed. Our frameless flat roof skylights give you more glass and less frame, at a lower price than a pitched roof lantern.

How to Measure for a Flat Roof Skylight

Our skylight sizes are external - the full size of the glass unit that sits on your upstand. The internal opening is 200mm smaller in each direction, so a 1200 x 1200mm external rooflight suits a 1000 x 1000mm internal opening. Measure your roof opening timber to timber, then add 200mm to the width and the length to choose your size.