Flat Roof Skylights, Rooflights and Windows

This high-performance, a non-opening frameless skylight is triple glazed with 6mm toughened, self-cleaning glass and a U Value.

  • Best prices and highest quality
  • UK stock. London and the surrounding areas within M25 - delivery is free of charge
  • 20 years warranty
  • Discount for bulk purchases.

Are you looking to make an impact on your living space by installing skylights? HiSky Limited provides a wide selection of flat roof skylights of exceptional quality to homeowners and business customers alike. We have various stock sizes of roof lanterns, electric opening rooflights, and flat roof lights, as well as manual opening rooflights. They are available in different sizes, ready to suit your needs.

Get in touch with us to buy flat rooflights: +44 7714 991494

What are Flat Glass Rooflights / Rooflights for flat roofs

A glass roof light is a roof skylight that is installed on your rooftop enabling natural light to enter the space through a translucent glass. It is usually used for ventilation and daylighting purposes. Our skylight range gives you twice as much light as vertical windows.

A rooflight adds value to a home and can completely transform a room. It has its advantages and disadvantages.

These days, more people are looking at this option to add more comfort and fresh air, as well as to make their places more energy efficient.

Why Choose Our Glass Skylights Service and our rooflights for flat roofs

  • Seamless design
  • Price match guarantee
  • Strict independent testing
  • High-quality durable materials
  • A wide range of standard rooflights with excellent thermal performance
  • Great variety of size combinations including standard sizes and bespoke sizes
  • Trained experts in glazing and glass
  • Next-day delivery for orders made by 1 pm; standard delivery time for other size and specification flat rooflights - 3-5 working days
  • Cost effective service

We offer a range of flat roof options for you. Think skylights for flat roofs with clear toughened glass top pane sealed with toughened Low-E glass, opening rooflights, fixed rooflights, and more, to achieve a centre pane 1.1 u-value. When installed the right way, rooflights look amazing and classy.

We work with the most professional and reliable suppliers in the market. That’s why the materials we use are of the best quality, capable of withstanding years of wear and tear. This way, not only do we help you achieve the desired aesthetic but we save you lots of money in the long run as well.

Benefits of Flat Skylights, Roof Lanterns, and Flat Roof Windows

Skylights open up the space, letting in tons of natural light for you to enjoy. At the same time, they add privacy.

Natural light brings your interior spaces to life in a way that a lamp simply can't. Discover the changing light of the seasons and the hours of the day anywhere with a rooflight.

Aside from enjoying the sunlight, there are other perks. Passing clouds, the moonlight, and weather changes get reflected, giving your living room a whole new look.

You can assemble a rooflight anywhere as long as there is a distance of 6 m or less between the ceiling and the roof. Home offices, bedrooms, and even bathrooms will do.

The new generation of rooflights now incorporates a slew of improvements to make installation a lot easier. Tube assembly takes half the time.

Solar Control Performance Enhancement and Maximum Light Transmission

Skylights come with special glazing that helps you control solar gain. It is typically made of plastic or glass and there are different types. Triple and double glazed skylights are commonplace.

A double glazed unit comes with two panes of glass. They are sealed with a clear argon gas. Triple glazing implies that the rooflight has three panels, which offers additional insulation not available in the double-glazed option.

While it seems that triple panes are the obvious winner due to their insulation abilities, this isn’t always the case. The reason is that this unit doesn’t let enough light in, so if you live in the British climate, you won’t be able to benefit from your skylight.

Yet, if you reside in a climate with intense sun, three panes of glass are your best bet. Blue or Grey tint glass can help reduce glare and heat build-up, as well as to improve UV protection.


As we deliver your package, we leave it up to you to organise the process of unloading. Since our driver is on their own, other people will be needed to pitch in to get the job done. We are not insured to off load and will not be held liable for broken skylights during the unloading process.

Flat Roof Construction: How to Measure the Opening for Your Flat Glass Skylight

Buying a skylight is just one of the steps you need to take before you can upgrade your room. The first thing you need to take care of is to measure the structural opening for the rooftop. When doing so, you should provide 5mm tolerances all around so that the bottom pane can fit in seamlessly. The top pane of standard units comes with a 100mm overhang all around.

So, if you select a size that says 1000mm x 1000mm rooflight, it reflects the size of the top pane of glass sitting on top of the upstand. Sometimes flat rooflight is fixed onto a timber kerb that is prepped by a builder ahead of time. You can ask for the top pane to be made bigger for an additional cost.

As for the bottom pane of glass, you can expect it to be smaller by 100 mm on both sides, which equals 800mm x 800mm.

The timber upstand should protrude at least 150mm above the roof. You need the pitch to be 5 degrees, which is considered sufficient to allow water to flow down in a breeze. It is important to install the skylight at the recommended pitch since this ensures that any water or dirt will be diverted away from the item, rather than pooling on the glass.

If you want the pitch to be completely flat, water will collect on the top of the rooflight glass, which won’t affect the performance or cause leaking issues. Rather, it means there will be visible water when looking up at the skylight.

If you do choose to install your skylight at a lower than the recommended pitch, we suggest pouring water over the top of your skylight before you begin. This will help you determine if the water flow drifts smoothly off from the unit before it is assembled.

As mentioned above, water could pool on the top of your glass if your skylight is installed completely flat, so you want to avoid that.

If you do choose the self-clean option, you should be aware that it works more effectively at pitches of 10 degrees or above.

Next, you have to smear the top part of the upstand with low modulus silicone as per the directions on the silicone supplier’s data sheet. Then you put the top pane rooflight ontop.

Now, when you use sealants, you need to ensure they are compatible with Dowsil 3363. Just so you know, the likes of Dowsil 791 low modulus weather proofing silicone and Dowsil 895 Structural sealant are okay to use with Dowsil 3363. To make sure the silicone spreads to all areas and fills any gaps evenly, you should exert pressure around the 100mm overhang.

And then, to finish the roof prior to installing the skylight, you need to put a roof covering to the side of the upstand to make it wheatherproof. Now, the bottom and top panes of glass should be fully supported.

Having Trouble Choosing a Roof Window or Skylight for a flat roof?

Don't worry, we are here to give you guidance on the things to watch out for. We'll help you to not only select the best pieces but also take measurements of the opening for your rooftop. And we have an installation guide in case you are interested.

It is important to note that all our units are made to order. Essentially, this means that once the glass is cut and toughened, we cannot make any more alterations to it. For this reason, we do advise that you review all the sizes and instructions well ahead of time before you place that order.

Frequently Asked Questions about Our Flat Roof Skylights

Can you put a VELUX window on a flat roof?

Yes, absolutely you can, however, we are not currently working with Velux at this moment. Still, we recommend calling us to double-check or to learn more about alternative options. In general, it is possible to install a Velux window on a flat roof, which can bring more natural daylight into a room.

Can you put a skylight on a flat roof?

Yes. There should be no doubt about it.

How long do flat roof lights last?

Depending on the type of glass you select, flat roof lights can withstand 15-20 years of wear and tear.

Roof lantern vs skylight - what’s the difference?

Skylights, or roof lights, are installed at the same angle as the roof. While roof lanterns add height to flat roofs and tend to be assembled at an angle. Skylights work for pitched roofs too but the same doesn’t apply to roof lanterns.

What size do I order?

Check out our size guide or consult our team of specialists if you are not sure what size of skylights you need to order. You can either take measurements yourself and submit them to our staff or let us come to your place to get the job done.

Do I require double or triple glazed?

It depends on your goals. Without a doubt, units with three panels offer more benefits in the winter since they are more energy efficient but they miss on solar gain during the rest of the year. These also let less sunlight in, which can be a deal breaker for some people.

Solar gain is basically the free heat you get from the sun as it hits your flat glass rooflight. So, if your home is situated in an area of intense sun, three panes of glass are the best option but if you happen to live in an area with less sunlight, you should consider the two-layer alternative. It suits the British climate better.

Do I have to maintain my flat skylight?

Yes. You need to do a little bit of maintenance throughout the year. For starters, you should keep the glass clean using some water and mild soap. Next, it’s recommended that you check the seals around the skylight for cracks and gaps. Also, clear your downspouts and gutters from debris to prevent leakages.

Can flat sky lights be used in commercial settings?

Yes. But keep in mind that glass flat roof lights and flat roof lanterns have their drawbacks, such as leakage accidents, safety issues, too much brightness, and excess heat.

Buy Our Skylights for Flat Roofs Today

Check out our wide range of roof lights and enhance any space in your home. With a few clicks, you can transform your home. Our customer support will help you with anything you don’t understand and offer guidance on your selection process. We are looking forward to partnering with you in this journey of yours.

Make a call now: +44 7714 991494