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Installation Guide


When it comes to windows, a vertical one lets in less natural light than a window on the roof. Skylights offer an interesting solution to a room. Many people want to install a skylight on the roof, as part of a home improvement upgrade. If you too have decided that a new skylight may add to your home, installing one is definitely a great decision.

Some benefits of installing skylights in a room

  • Saving on energy costs
  • The improved resale value of the home
  • Makes the room feel bigger
  • Makes the room lighter 

Skylights need to meet local codes for load, wind resistance and other factors. That is one reason why usually skylights are installed by professionals. They have the equipment needed to deal with working on the roof and installing the skylight kits. They also know how to follow the process through and through, from drilling a hole in your ceiling to ensuring the skylight's ice and water shield is in place.

Still, if you think you have what it takes to work on top of the roof, drill a hole in the ceiling and use a circular saw among other equipment needed to equip a skylight in your home, then it is possible to install one on your own.

A competent trade person can easily install our skylight.

We can proudly guarantee the quality of our products, but the installation sequences and use of appropriate materials must not be underestimated. Mistakes and poor installations can lead to various issues. Therefore we feel obligated to provide a step-by-step installation guide.

Instructions and diagrams provided on this page are for guidance for installers to achieve sound installation. 

But sometimes, the design of the up-stand and dimensions can vary based on the architect's approved drawings and insulation requirements.

Step-by-Step Skylight Installation

The up-stand opening should allow for 5mm tolerances on each side to allow the bottom pane of the skylight to fit smoothly into the space. For example: if your quoted size skylight is 400mm by 400mm, we recommend the opening to be 410mm by 410mm.

Please remember that the top glass of our product is stepped by 100mm all around.

If the quoted size of the skylight is 400mm by 400mm, the top panel will be 200mm more extensive on each side, 600mm by 600mm.

The pitch should be at least 5 degrees to avoid water pooling in the middle of the glass.

Before sealing the product with silicone, we advise running water and testing the water flows; no pooling occurs.

Good quality timber upstands must protrude 150mm above the roof level.

  • You can apply your roof covering material to the side of the upstand to make it weatherproof. Once the weathering of the up-stand is completed, you are ready to install the skylight.
  • As mentioned, the upstand opening should allow for a 5mm tolerance on each side.
  • We recommend the skylight support shown in yellow on the diagram to be 25mm by 50mm(2” by 1”) timber.
  • Ensure all areas where the silicone is applied are clean and dry.
  • Apply foam rope on the top of the supporting wood (25mm by 50mm ); this is very important. This will prevent pressure on the bottom glass pane.
  • Apply reasonably weatherproof sealant on top of the upstand. We recommend good quality weatherproof sealant.
  • Position the skylight with suction cups.
  • Apply weatherproof silicone on the underside of the overhang

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


  • There is only one difference between the installation of our flat roof skylights and pitched roof skylights. Namely, on the pitched roofs there are tiles, which have to be sealed to the up-stand using lead flashing tape. We recommend 450mm flashing to be wrapped around your up-stand sealing it to your roof tiles.
  • Our Skylights can be installed at a maximum pitch of 45 degrees.

Flashing Installation Guidance  

  1. Installing the flashing - prepare your flashing kit for installation along the window sill. This is the first line of defence against potential leaks. Ensure a strip of the self-adhesive membrane is applied properly on each side, and then cut enough to fold over the edges of the skylight. The goal is to have the barrier with the width of the skylight sill. Nail down the sheathing on all sides by using the roofing nailer.
  2. Sealing the edges - you are not done with the sealing just yet. Cut strips of roofing paper or self-adhesive membrane to cover the flanges just a few inches beyond the edges. Affix the bottom flashing piece first, then the sides and then the top. Lift the roofing nails that would get in the way with a pry bar, but be careful not to damage the shingles. The goal is to create another barrier against leaks, at least 6 inches from the corner of the skylight. It is an important task to go through before installing the sill and step flashing.
  3. Installing sill flashing - your skylight should come with a piece of flashing that you install on the bottom sill. Once it slides in place, secure every corner with a roofing nailer. Finally, install each roof shingle in place. The sill flashing should be covered in the process. Note that you will only install this on the bottom of the skylight.
  4. Get to the step flashing - the next step of the process is to get each side equipped with step flashing. Usually, you will start at the bottom and work up. Put the L-shaped step flashing piece at the bottom of the skylight. Nail it in and cover it with a shingle. Afterwards, install the next step flashing to overlap the top half by just a few inches and put the next shingle piece in place. You will go through these steps on each side till you get to the top corners.
  5. Counterflashing - counterflashing should click into place nicely over where you installed the step flashing. This is a very important step so make sure everything fits in nicely. It will guarantee that snow and rain will not get under the edge of the roof window. It usually surrounds or goes on each side of the skylight.
  6. Saddle flashing - this is similar to sill flashing, with the only difference being that it goes on the top part. The way you install it is by sliding it in place under the shingles. Use roofing nails to secure it and then reinstall the top half of the shingles as before.
  7. You are pretty much done - with the shingles, flashing and fixed skylights, you are almost done. All you have to do is double check if it looks good on the inside. If you have a type of skylight that opens, test it to ensure it is smooth.

All of these steps may sound simple, but for anyone with a lack of expertise, it is best to contact professional skylight installers to deal with the job.

Common skylight installation challenges

  • Installing skylights to a truss-framed roof - it is still possible to fit skylights to a truss-framed roof. However, you may need to settle for smaller skylight size, because of the limited space between the beams of each truss.
  • Installing skylights in an attic - if a room has an attic above it, you can build a light shaft. It is a frame that tunnels the light from the skylight to the room below. Ensure the most light comes through by flaring the shaft on all four sides.
  • Installing on a metal roof - if you have a corrugated metal roof, you have to position the skylight below the roofing lap and align it well with the grooves on the fins.
  • Becoming a heat trap - if there is strong sunlight in your area on hot days, you should get shades or blinds. Another alternative is to have a ventilating skylight, which allows the hot air to escape. Vented skylights

Frequently Asked Questions about the Installation of Rooflights

Do all skylights leak after some time?

This was more of an issue in the past when leaking skylights were common. Nowadays, designs feature improved sill flashing for almost no chance of leaking. As long as the installers follow the right steps during installation, saddle flashing comes with a guarantee against any water infiltration.

For example, if your roof has rafters, you should consider doubling the rafters on the side and nailing a double-headed sill to the top and bottom parts of the opening.

How to install a skylight on a flat roof?

The roof does not need a slope to support skylights. The installers simply need to be careful in how they build the curb. It needs a slight angle so water can run off to the sides. Skylights with curved glasses work just as well.

How to install a skylight on a tile roof

Usually, curb-mounted skylights work ideally for tiled roofs. Before establishing the skylight, a contractor will build a curb around the roof opening and then weave the flashing into the shingles.