Glass Rooflight Fixed and Custom Sizes

Easy and Hassle-free Fitting

The rooflights we provide are easy for roofers or builders to install. To assist with installation, we supply a comprehensive, step-by-step guide along with technical support documentation.

Each rooflight can be conveniently installed on an insulated upstand with an anodized aluminum angle trim, which your roofer or builder can supply. The installation-related diagrams and information on this page are for general guidance only, as each project may vary in design and construction according to the architect’s drawings. Upstand dimensions and design may also vary based on the architect’s specifications and insulation requirements. If needed, your rooflight can be custom-designed at an additional cost to accommodate wider upstands with larger than 100mm overhangs.

General Installation and Measurement Guidelines

Our frameless rooflights are straightforward to install for any competent roofer or builder.

Below, you'll find a simple fitting guide outlining each step. For technical support, you can contact us via email or phone.

How to measure the opening

Before you can buy your rooflight, the first step is to take measurements of the structural opening where you want the rooflight to go. It is recommended that at least 5mm tolerances should be allowed all around the structural opening in order to let the rooflight’s bottom pane fit effortlessly into the opening.

For instance, if you purchased 1000mm x 1000mm rooflight from our drop down menu this will be the size of the top pane of glass that rests on top of the upstand. The bottom pane of glass will be 100mm smaller all around which would make the bottom pane 800mm x 800mm. You would make the structural opening 810mm x 810, upstrand width up to 65mm wide and height 150mm high in this example.

For all standard rooflight units, the top pane has a black 100mm boarder and a 100mm overhang all around. The top pane can be made bigger for bigger upstand width if required at an additional cost.

For clarity as another example, if you purchase a 1000mm by 2000mm from our drop-down menu on our website. For this size skylight the bottom pane that slots into the structural opening will be 100mm smaller all around making it 800mm x 1800mm which means your structural opening should be 810mm x 1810mm. Upstand width should be up to 65mm wide and 150mm high, allowing a 35mm lip on each side of the top pane as per diagram below. The diagrams below should give you further insights:

How to prepare your roof

The rooflight insulated glass unit (IGU) is mounted on a timber kerb, which your roofer or builder will prepare during the flat roof construction.

It is crucial that the timber upstand extends at least 150mm above the roof surface. Additionally, ensure that the pitch is a minimum of 6° to facilitate proper water drainage and prevent water from pooling on the glass surface.

How to install your rooflight

The last step required to finish the roof before you can install your roof light is to apply a roof covering to the upstand’s side, which makes it weatherproof (illustration below).

Just to quickly reiterate, it’s important to get the timber upstand protrude by at least 150mm above the roof – the pitch should be 6°, allowing rainwater to flow down with ease. Before sealing the product with silicone, water can be applied to test the flow off of water, if pooling occurs a higher pitch may be required.

Apply a reasonable amount of low modulus silicone to the Upstand’s top part according to the silicone supplier’s data sheet, after which you can place the top pane rooflight onto the top of the upstand . Apply pressure all around the 100mm overhang so that the silicone spreads evenly and seals any gaps. Finish the silicone with a silicone finishing tool.

Next, the bottom pane needs to be supported on all four sides after it is set in place with the aluminum angle fitted and bonded prior to the plasterboard. Secure the aluminum angle to the timber structure. Apply compatible structural silicone between the bottom aluminum angle trim’s surfaces and the bottom pane of glass according to the supplier’s data sheet, and firmly secure into place. Wipe away any excess silicone using a finishing tool. The aluminum angle can then covered with plasterboard.

The bottom and top panes of glass at this stage are fully supported. Only sealants compatible with the top of the upstand, glass, aluminum angle trim and setting blocks should be used. Sealants used should be compatible with Dowsil 3363. Dowsil 791 low modulus weather proofing silicone and Dowsil 895 Structural sealant are compatible with Dowsil 3363. Some sealant suppliers may require primer to be applied to surfaces.

Our rooflight systems are ideal for a variety of properties, ranging from single-storey flat roof extensions to fully developed residential areas. This frameless rooflight product is manufactured to the highest specifications with clear, uv protected glass as standard and a range of extra options. This means the rooflight supplied has exceptional thermal performance and noise reduction.

• Premium Quality

• 10 Years Warranty

• Price Beat Guarantee

• Easy Clean, blue/grey tint or Solar Glass Options

• Designed and manufactured in UK
• Suitable for Flat and pitched roofs
• Double Glazed
• UV Protection

• Exceptional Thermal Performance

• Easy Installation Guide

• Top Pane Glass: 6mm BS EN 12150 Toughened Glass

• Spacer Type: Black Warm Edge

• Air Gap/Spacer: Warm Edge Spacer bar Argon Gas Filled Structurally Bonded

• Bottom Glass Pane: 6mm Low EBS EN 12150 Toughened Glass

• Clear Glass

The first 7 sizes of clear glass options listed in the website drop-down menu can be delivered within 2-5 working days in most areas. For other sizes and specifications of flat rooflights, our standard delivery time in the London/M25 area is 7 to 10 working days, depending on your specifications. Delivery times in other locations may vary. Third-party transport services deliver to specific areas on designated days of the week, with deliveries occurring between 7 am and 6 pm, Monday to Friday. Some areas may not be eligible for delivery of this product based on third party delivery capabilities. 

After your order paperwork is processed, we will provide a delivery date within a few working days. Please ensure that labour is available at your premises to unload your product from the third-party delivery van, as drivers are not insured to do so. The recommended lift per person is 25kg.

The product is delivered in a specialist glazing vehicle without packaging, allowing for easy inspection upon delivery. We recommend arranging equipment and installation only after the item has been delivered. We are unable to deliver this product to Isle of Wight.