DIY – How to install a skylight

Set up
How to install a a skylight can vary but this is our take on it in the hope it may be of some use to the DIYer.

Set up all appropriate drop sheets for the job. If it is going to be a “messy” job place drop sheet divides between the rooms and or close the appropriate doors.

Locating the position of the skylight installation

NOTE: Always check the final skylight location before making final larger cuts.

How to install a skylight on a tile roof – When locating a tile roof skylight it usually easier to measure off the walls to the desired location. Line the location up with something outside and then mirror the same measurements once on the roof. (You can place a marker on the gutter if that helps you keep the correct starting point). Before getting on the roof take note of any light fittings or ceiling fittings that may help you with your location when looking inside roof. (Even turn on the lights as this can be like a beacon of correct location, then simply measure how far off the light the skylight needs to be.) Once you have measured out the approximate location of the skylight, kick up the tiles and check your location from the top. When you are happy with location with regard to truss, baton and tile lines drill a small 1/8 hole so you can easily locate it from the bottom when cutting in the ceiling surround

How to install a skylight on a colorbond roof – When locating on a color-bond roof it is usually easier to access the manhole and locate it from within the roof cavity. Simply measure off a light fitting to locate where you need to be. (if there are down lights in the house be sure to turn them on as they are a great help) Once you have drilled a hole locating the ceiling surround, drill another corresponding hole above that in the color-bond roof, locating the position of the top flashing. It helps to drill a larger roof screw threw the roof sheet to help you locate your position once on top of the roof.

Cutting in the skylight ceiling surround

Round – Cut yourself a smaller peep hole before you cut around the perimeter of the section to check for power or light leads that could be present. Once you happy that the section is free of hazards and clear for the surround to fit, cut out the measured section. NOTE: check light fittings, that may be close by, are firmly secured as they can wriggle loose
with vigorous cutting or sawing. Once all this has been checked and completed you are free to fit the skylight ceiling surround using the appropriate fixings.

Square/ Rectangular – Cut yourself a smaller peep hole before you cut around the perimeter of the section to check for power or light leads that could be present. Once you happy that the section is free of hazards and clear for the surround to fit, cut out the measured section. NOTE: check light fittings, that may be close by, are firmly secured as they can wriggle loose with vigorous cutting or sawing. Once all this has been checked and completed you are free to fit the ceiling surround using the appropriate fixings.

How to Install a Skylight Flashing

Depending on roof type you will have to make various cuts to suit the roof you are on.

How install a skylight flashing that is corrugated.

Installing a corrugated skylight flashing is a relatively straightforward process. Here are the steps to follow:

1. Gather the necessary tools and materials: You will need a corrugated skylight flashing kit, a tape measure, a pencil, a hacking knife, a utility knife, a drill with a metal bit, roofing screws, roofing sealant, and a ladder.

2. Measure, mark and cut the skylight opening: Use a tape measure to determine the dimensions of the skylight opening on your roof. Mark these measurements on the roof using a pencil. An old chisel can be used as a hacking knife in conjunction with a hammer. Then score and shape the roof sheet to make your opening.

3. Trim the flashing: Using tin snips, cut the corrugated skylight flashing to match the dimensions of the skylight opening.

4. Position the flashing: Place the flashing over the skylight opening, ensuring that it is centered and aligned properly. The flashing should extend beyond the edges of the skylight opening. On a corrugated sheet you will have to turn up the valleys on the bottom cut so driving rain will not cause any leakage.

5. Secure the flashing: Insert the skylight flashing under the roof sheet at the top and over the cut out. Use a drill with a metal bit to create pilot holes through the flashing and into the roof. Insert roofing screws into the pilot holes and tighten them to secure the flashing in place. Make sure to space the screws evenly along the edges of the flashing.

6. Apply roofing sealant: Apply a generous amount of roofing sealant around the edges of the flashing, both on top of the flashing and underneath it. This will help create a watertight seal and prevent any leaks.

7. Inspect and clean up: Once the flashing is securely installed, inspect it for any gaps or areas that may need additional sealant.

It is important to note that these are general guidelines, and the specific installation process may vary depending on instructions and the type of skylight flashing you are using.

Attaching the replacement skylight shaft

On the roof – Before placing the skylight dome on the skylight the shaft has to be dropped down to the opening below. This can be fixed either with clips to the lip of the skylight flashing (flexi shaft) or with a bead of silicone and a lining of silver tape (foil shaft). Once the top is secured and trimmed etc. fix the replacement skylight dome on the skylight with the appropriate screws and washers provided.

Inside – Make sure you pull the skylight shaft as taught as possible and free of any creases as possible as this will increase the amount of reflected light travelling down the shaft. NOTE: never have more than a 45 degree angle on your Skylight shaft. If there needs to be more than that than you have positioned it incorrectly. This sort of angle will not reflect the required amount of light to make the skylight shine to its full potential.

How to install a replacement skylight diffuser

The diffuser should always be placed in the surround with the rough side facing down as the prisms refract more light over a larger area. If the replacement skylight diffuser is not prismatic then obviously this does not apply. Diffuser have a certain amount of flexibility in their material. This allow you to bend and twist them slighly in order you get a tight fit in the skylight ceiling insert.

If you have any other questions on how to install a skylight please call Skybrite on 1300 186 262.