How to Install a Skylight in Your Home

Anyone looking to bring a warm and inviting feel to their space should consider installing residential skylights in their roof. These windows have the power to brighten up even the dimmest, darkest spaces, and they can even help you regulate the temperature in your home throughout the year. Surprisingly, adding a skylight is not all that complicated of a process, and you can actually do it yourself if you have the right skills, tools and knowledge. In this guide, we’ll go over the basics of skylight installation to help you master it. 

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What You’ll Need 

Luckily, installing a skylight doesn’t require any specialty tools, and you can get all the essentials at your local hardware store. In fact, you might already have some of these tools laying around. In addition to your skylight and flashing kit, you’ll also need the tools and supplies listed below. Depending on the scope of your project, installing the light could take between a few hours and a couple of days. 

tools and supplies youll need

  • Safety harness
  • Circular saw
  • Reciprocating saw
  • Measuring tape
  • Chalk line
  • Carpenter’s square
  • Utility knife
  • Flat pry-bar
  • Stud finder
  • Hammer
  • Drill
  • Level

Step-by-Step Guide to Installing a Skylight

Learning how to install a skylight may be a lengthy process for those who aren’t already familiar with some basic roofing concepts. We always recommend consulting with a professional if you are not comfortable with this level of DIY or working at heights. However, if you do decide to install a skylight yourself, you can expect to cover the following steps. 

tip before you begin

Tip: Before you begin, remember to check with your local building code to make sure you don’t need a permit to install your skylight.

Thoroughly read through the manufacturer’s instructions before you begin your installation, as it will vary depending on the style, size and type of skylight you choose. VELUX skylights, sun tunnels, etc. come with installation instructions that have step-by-step illustrations, making it easy to read and easy to install. You can also download a PDF version of the instructions.

Visit our installation page for information on how to install VELUX curb-mounted skylights, deck-mounted skylights, pan-flashed skylights and more. Note that each style of skylight comes in fixed, electric, manual and other styles, so be sure you’re referencing the correct installation guide. You can always reach out to us if you need help determining which instructions to use.

1. Plan Your Installation

The first step is to think through your plan and choose the right skylight. 

Be sure you have the right kind to suit your roof’s pitch and the construction of your home. Choose a curb-mounted skylight for lower-pitched roofs (those with a pitch between 0 and 60 degrees) and a deck-mounted skylight for higher-pitched roofs (those with a pitch between 14 and 85 degrees). For smaller spaces and challenging areas, consider installing a sun tunnel instead.

roof construction and skylight installation

Next, look at the ceiling where you plan to install the skylight. Take note of the way your home was constructed. Does it have rafters or trusses? The distance between your trusses or rafters will also determine how big or small your skylight can be. While rafters can usually be cut, it’s much harder to alter the size of trusses, so keep this in mind when sizing your skylight.

During this phase, you’ll also want to determine the location where you want the skylight to be placed inside your home. All of these factors will help you decide on the size and type of skylight required as well as the price. 

2. Cut and Frame a Rough Opening

The rough opening of your skylight is the opening on the interior of your home. It will help make the cutting process cleaner, easier and more accurate once you get onto the roof. If you opt to install the skylight in an attic or crawlspace where the walls are unfinished, you can skip any steps involving drywall. 

  • Locate and mark the rafters in your ceiling using a stud finder. Using your measuring tape and a pencil, mark where you want to cut the rough opening.
  • Using your marks as a guide, cut a rough opening in the drywall to expose the inside of the ceiling and the rafters. If there is any insulation or a rafter in the middle of the opening, be sure to remove it during this step. 
  • Next, frame the opening using the dimensions of your skylight. Install supports perpendicular to the roof deck and follow all building codes. The size and type of the lumber you use for the framing will depend on the manufacturer and model, so make sure to check the instructions for information. 
  • To create an outline you can use when cutting the opening on the roof, install a long screw at each corner of the opening. This will help you easily identify where the skylight will go when you’re on the roof.

using leveling tool on skylight opening

3. Prepare for Working on the Roof

If you don’t regularly work at heights, you’ll need to brush up on some roof safety rules. Working on the roof comes at risk of severe injuries and even death, so you want to eliminate any risk factors you can before proceeding.

  • Always wear a roof safety harness to protect you in the event of a fall and consider installing roof anchors for extra security. 
  • Wear high-traction shoes while working on the roof. Before heading up, make sure the bottoms of your shoes are clean.
  • Avoid roof work if it has recently rained or there is rain, snow or severe wind in the forecast. 
  • Avoid roof work if it’s hot out. It’s also not a good idea to work on the roof when it’s especially hot out, as some roofs can reach temperatures of 150 degrees or higher in the summer.
  • Clean the area where you’ll be working to ensure it is free of water, leaves and debris that could cause you to slip. 

4. Prepare and Cut the Opening

Now that you’re wearing your harness and working on a clear, dry day, you can go ahead and start the roof portion of the installation. If possible, recruit a helper to assist with handling materials and the skylight itself. 

  • Prepare the roof by removing all the shingles within the four screws as well as about six to 10 inches surrounding it. Snap a chalk line between the four screws or use a straight edge to mark exactly where you want to cut your opening.
  • If working with a curb-mounted style, you will need to build a curb according to the manufacturer’s instructions. The curb’s height should comply with building codes and be secure enough to transfer the skylight loads to the framing.
  • Using a circular saw, cut the opening following the chalk line. Have your helper hold onto the roof portions that are being cut so they don’t fall into your house and create a mess. 
  • Remove the roofing underlayment about six inches surrounding the opening to accommodate for the water shield.
  • Thoroughly sweep the area, making sure to clear away sawdust and dirt.

installing a skylight steps

5. Place and Seal the Skylight

Now it’s time to place and seal the skylight. Be sure to work in a flat, secure area while unboxing the skylight, keeping all the original pieces and parts neat and tidy nearby. Some skylights come with multiple layers of surrounding materials to make them weatherproof. For example, VELUX skylights are sealed with deck seal, flashing and adhesive underlayment. This creates multiple layers of protection against leaks and seals out wind and debris.

  • With help from your partner, place the skylight over the opening and center it. Rest the bottom edge of the skylight against the sill and carefully lower it into the opening. Have your partner help you balance the skylight as you place it.
  • Nail the flange into place using the nails provided in the original packaging. If not provided, use 1.25-inch galvanized roofing nails.
  • Install the ice and water shield underlayment around the frame of the skylight. Cut slits in the corners of the shield so it wraps around the corners of the skylight. Be sure to install the membrane over the flange, allowing it to extend about six inches past the skylight’s edge on each side. Secure the membrane to the sides of the skylight and the roof deck to create a water-tight seal.

6. Install Flashing and Connect the Solar Panel

The flashing is the part of the skylight that helps keep the surface dry without the help of less reliable sealants which could damage your roof. This is an important step in helping to keep your skylight completely water-tight, so make sure to follow the directions closely.

  • Using roofing nails, nail shingles to the bottom part of the ice and water shield.
  • Place the sill flashing (the U-shaped flashing pieces that come with your skylight) at the bottom edge of the skylight. 
  • Nail the flashing into place and secure it with roofing nails. For fixed skylights, be sure to pull the rubber gasket at the bottom of the skylight over the side of the sill flashing to allow for proper drainage.
  • Install the side flashing and shingles. From the bottom up, nail in shingles and flashing all the way up the sides of the skylight. Nail each step piece with two nails.
  • If you’re installing a solar skylight, the next step is to attach the solar panel to the bottom of the skylight. Your skylight’s installation instructions will explain exactly how to attach the solar unit.
  • Replace the cladding around the body of the skylight and install the saddle flashing around the top of the skylight. 
  • Next, interweave the top flashing with the underlayment that covers the roof deck. Place the flashing under a seam or make a cut in the flashing to divert water to the top of the shingles.
  • Finish shingling the top of the skylight, ensuring there’s enough of a gap between the top of the flashing and the bottom of the shingles.

skylight on dark roof

7. Repair the Drywall

If you installed your skylight in a room with finished walls, you’ll want to patch things back up so it looks clean and neat. This step involves repairing the interior rough opening and fixing the drywall. You can skip it if you installed your skylight in an unfinished room.

  • Back inside, make sure there is a smooth transition between the skylight’s sheetrock groove and the framing members. You may have to cut shims to fill the gaps.
  • Replace any insulation you removed when creating the rough opening.
  • Install the screen and accessories. Electric skylights may require some wiring at this point, which should be done by a qualified electrician.
  • Repair the drywall. At this point, you can begin to repair the drywall and replace the portions you removed. Finally, finish it off with a fresh coat of paint.
In Need of a Sun Tunnel? We Have Those, too!

Hiring a Professional

While today’s skylights are designed to be fairly straightforward and easy to install, it’s always a good idea to rely on a professional if you aren’t comfortable with roofing or drywall. The great thing about these skylights is they’re approachable enough that virtually all general contractors and roofing professionals will be able to install them for you relatively quickly. 

We’re Here to Help

At Skylights for Less, we’re here to make the entire skylight installation process simple and painless, from selecting the perfect skylight for your home to installing it and maintaining it well into the future. Whether you have questions about installation or are looking for a specific instruction guide, our team of skylight experts are always available to help. Reach out to us with questions


Image Credits

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