Flat Rooflight – Cheap Sale Prices!

Grey Tint Glass Currently Not Available. Blue Tint can be supplied. Sizes Cannot be Changed Once The Order Is Processed. Please note sizes selected above are the bottom pane glass size.

This item is made to order
All prices are subject to 20% VAT

Custom Size
Easy fit
Made to Measure
Exceptional Thermal Performance
Price Match Guarantee for like for like product
Argon gas filled Toughened Glass
Solar Protection

Our bespoke Rooflights are perfect for visually expanding areas and other closed-in dark spaces that can be transformed with daylight and sky views. The seamless design with no joints ensures protection from water accumulation and mould build up.

TGS Skylights let in twice as much light as vertical windows and will make a great impact on your living environment. High quality materials are used in manufacturing our rooflights to ensure the product is attractive and economical with excellent thermal performance. All our rooflights are custom made to customer specifications to meet the desired u value required to comply with building regulations. For CUSTOM Fixed, Electric or Manual Opening Rooflights and Roof Lanterns please click here or contact us.

Unlike some of our competitors, this stepped rooflight system once installed as per our fitting guide has been through independent RVA accredited testing and met the requirements for Air Permeability (EN12207) and Water Tightness (EN12208).

Please note the size advertised on our drop-down menu is the visible bottom pane glass size, the top pane of glass is 100mm bigger all around. Most competitors will supply a rooflight with visible glass 200mm smaller than what they advertise. When comparing prices please consider this rooflight we supply lets in more light as the visible glass is larger.

Price Match Guarantee

We want you to get the best price for your purchase. This is why we promise to match the prices of other UK retailers.

High Quality Materials

High quality materials from reputable suppliers such as Pilkington glass are used in manufacturing our rooflights to ensure the product is attractive and economical with excellent thermal performance.

Measuring & Installation Guide

Easy fit


Our roof light rooflight installation can easily be undertaken by competent builders/roofers and we provide simple step by step fitting guide and technical support to facilitate installation.
The Rooflight supplied can be installed directly on the Insulated Upstand supported by an anodized aluminium angle trim all around, supplied by the builder or roofer.

All information and diagrams on this page are for guidance only to install the rooflight we supply as each project may vary in design/construction as per architects’ drawings. Upstand design and dimensions can vary based on architects approved drawings and insulation requirements. The rooflight can be custom made to suit wider upstands with bigger than 100mm overhangs if required at additional cost.

Installation and Measuring Guide

Our rooflight installation can easily be undertaken by competent builders and roofers. We provide simple step by step fitting guide. For technical support please contact 0203 633 3224.
1. Measure the opening
2. Preparing your roof
3. Installing the rooflight

Measure the opening

The first step in purchasing your rooflight would be to measure the structural opening where the rooflight will be installed. You should allow for 5mm tolerances all around to allow the bottom pane of the rooflight to fit smoothly into the opening. As an example, if your tight opening measurements are 1010mm by 1010mm we would recommend you purchase a rooflight with a bottom pane of 1000mm by 1000mm so it slots in smoothly.

For standard units the top pane would have a black 100mm overhang all around on the top pane. This would make the overall size of the top pane 1200mm by 1200mm in this example. We can increase the size of the overhang if required if the upstand width is wider. The diagram below shows the sectional view of a double-glazed installed rooflight.

Preparing your roof

Structural glazing silicone is used to bond the double/triple glazed sealed units to the top pane to form a rooflight. The rooflight IGU is simply secured onto the timber kerb built by your roofer/builder as part of the roof construction.
The timber upstand should protrude 150mm above the roof. The pitch should be 6 degrees, sufficient to allow water to flow down.

Installing the rooflight

The final step to finish the roof before installing the rooflight is to apply your roof covering up to the side of the upstand to make it weatherproof as illustrated below.
The timber upstand should protrude at least 150mm above the roof and the pitch should be 6 degrees, sufficient to allow water to flow down. 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.

Bottom pane should be supported on 4 sides once set in place, the aluminium angle can be fitted before the plasterboard and covered with plasterboard or fitted after the plaster board. Alternatively, a timber batten with aluminium strip on the top can be fitted to support the rooflight.

Apply adequate compatible low modulus silicone as per silicone supplier’s data sheet to the top of the Upstand firmly placing the rooflight onto the upstand. Pressure should be applied all around the 100mm overhang to ensure the silicone spreads and seals any gaps and then finish off the silicone all around with silicone tool. Once cured apply structural silicone as per supplier’s data sheet to the bottom aluminium angle trim flat surfaces firmly fitting them in place. Excess silicone should then be wiped away with a finishing tool. Dowsil 791 low modulus weather proofing silicone and Dowsil 895 Structural sealant are
compatible with Dowsil 3363. Setting blocks can be used to achieve sealant thickness required.
At this stage the bottom and top panes should be supported. Sealants compatible with the top of the upstand, aluminium angle trim, glass, setting blocks and Dowsil 3363 silicone should be used. Some sealant suppliers may require primer to be applied to surfaces.

Please note all rooflights are made to order and sizes can not be changed once glass is cut or toughened. We recommend the speciation, sizes and instructions are reviewed and understood by the installer before proceeding with an order.

Technical Information

Building regs and performance

The rooflight Stepped Insulated Glazed Units (IGU’s) we supply are suitable for single storey flat roof extensions to existing residential dwellings. As each project can vary with requirements, we suggest confirming building regulation requirements for the product with the architect, builder or building officer prior to placing an order to ensure compliance. The installer should undertake a risk assessment. For example, it may need to be obscure, triple glazed, bigger upstand, suitable for walking on, laminated, etc.

Standard units

Our standard units are double glazed with clear toughened glass top pane manufactured to BS EN 12150 and conform to BS EN 1279, 18mm argon-fill cavity structurally sealed with toughened Low-E glass to achieve a centre pane 1.1 u-value. Glass thickness for standard size units are 6mm toughened. Glass speciation and thickness will vary for larger units.

Triple and quad glazed units

Our triple and quad glazed options provide even higher performance ratings. 1.6 minimum U-value rating is currently required to comply with building regulations. The solar control layer prevents heat escaping and reflects interior heat back into the room

TGS Skylight Thermal Ratings

Optional Extras

Coloured boarders – If required we can paint any RAL colour to the boarder which is usually 100mm wide all around.

Pilkington Activ self cleaning glass – Applied coating breaks down dirt and washes away with rain water.

Pilkington Activ blue self cleaning glass – In addition to self cleaning properties the blue tint provides additional solar control performance by keeping internal temperatures cool whilst maintaining light transmission

Triple glazed skylights – achieving 0.9 centre pane U Value rating.

Privacy glass – We can apply a sandblasted frosted layer to make the skylight obscure.


The product is supplied with a manufacturer’s warranty. For warranty terms please see our terms and conditions.

Delivery & Lead Time

Standard manufacturing lead time for custom made flat roof skylights is 7–12 working days in the London area depending on the specification. Delivery will be made from 7am to 6pm We provide a delivery date within 3 days of processing the sale. National delivery lead times will vary. You would need to ensure labour is made available on site to off load the glass from the vehicle.

For this product we offer free London delivery. Delivery charges on the website apply to postcodes and counties below. If delivery is outside of these postcodes/counties, please contact us.

N, EN, E, IG, RM, SE, DA, SW, W, TW, EC, WC, NW, CM, CO, SB, SS, HA, UB, WD, SG, LU, HP, OX, MK, SL, GL, SN, RG, BS, GU, SP, SO, BA, KT, SM, CB, CR, BR, ME, CT, RH, TN, NN, LE, B, CV, WR, WS, N, NW, E, SE, SW, EC, W, PO (exc isle of White)

Bedfordshire, Berkshire, Buckinghamshire, East Sussex, Essex, Gloucestershire, Hampshire, Hertfordshire, Kent, Leicestershire, Middlesex, Northamptonshire, Oxfordshire. Surrey, Warwickshire, West midlands, West Sussex, Wiltshire, Worcestershire, London.