Installing an angled skylight can dramatically change the look of your living space, bringing in natural light and creating a sense of openness. This project requires careful planning and execution but is manageable if you have solid do-it-yourself (DIY) home improvement experience.
In this guide, we’ll walk you through the process of installing an angled skylight. We’ll cover important considerations such as energy efficiency, maintenance, and building codes to ensure your skylight installation is smooth and long-lasting.
Planning Your Skylight Installation
First, think through how to set up your skylight project. Here’s what you should consider.
Assessing Structural Requirements
Before doing anything, assess your roof’s structure to ensure it can even support the skylight. Check for any electrical wiring, plumbing, or HVAC components that may need to be relocated. If necessary, consult a structural engineer to determine if you’ll need additional framing.
Choosing the Right Location
Select a location that maximizes natural light while avoiding potential obstructions. In attics or bonus rooms, skylights are typically installed in the sloped ceiling, just above the knee wall. This placement puts the sill about 5–6 feet above the floor, perfect for capturing natural light.
Determining the Best Angle
The best angle for a skylight depends on your location and the pitch of your roof. Generally, skylights should be installed at an angle equal to or greater than the latitude of your location plus 5–15 degrees. This ensures proper water drainage and optimal light throughout the year.
Obtaining Permits and Budgeting
You’ll likely need permits for installation. Your local building department can provide guidelines specific to skylights, ensuring compliance with regulations. Budget for this along with materials and potential contractors if you’re hiring professionals.
Tools and Materials Needed for a Skylight Installation
You’ll need these tools to complete the project:
- Caulking gun
- Drill/driver
- Drywall knife
- Drywall saw
- Hammer
- Reciprocating saw
- Roofing nails
- Safety equipment (goggles, gloves, harness)
- Tape measure
- Utility knife
You’ll also need these materials and hardware:
- 1/2-inch plywood
- 2×12 lumber for header
- 2×4 lumber
- Drywall
- Flashing kit
- Insulation
- Joint compound
- Paint
- Roofing felt
- Shingles
- Skylight unit
Steps for Installing the Skylight
We will provide the step-by-step process for installing a skylight below.
Step 1: Marking and Cutting the Rough Opening
To begin the installation, mark the rough opening on the ceiling and knee wall, positioning the bottom of the sill 38–44 inches above the floor. Align the side of the opening with the inside edge of a rafter. Cut along the marked lines using a drywall saw and remove the drywall from the rough opening.
![cutting the drywall for a new skylight](https://s42814.pcdn.co/wp-content/uploads/2019/12/skylight_01.jpg.optimal.jpg)
Step 2: Preparing the Roof
Once the interior is prepared, remove insulation from the opening area. Use a reciprocating saw to cut out the top plate of the knee wall and the rafter from the center of the opening. Build a perimeter frame around the sill area with 2-by-4s. From the roof, carefully remove shingles around the opening, saving them for later use.
![cutting the inside of a roof](https://s42814.pcdn.co/wp-content/uploads/2019/12/skylight_02.jpg.optimal.jpg)
Step 3: Installing the Skylight Frame
Cut out the rough opening from the inside using a reciprocating saw. Remove the sash from the skylight frame and pass it through the opening onto the roof. Set the frame in place and reinstall the sash to maintain squareness. Fasten the frame to the roof using 2-inch screws driven through the metal brackets on the sides of the frame.
![installation of a skylight frame into a roof](https://s42814.pcdn.co/wp-content/uploads/2019/12/skylight_05.jpg.optimal.jpg)
Step 4: Flashing and Weatherproofing
Weatherproofing is key to ensuring that your skylight is well-sealed against the elements. Staple 18-inch-wide strips of roofing felt around the skylight frame’s perimeter. Install sill flashing along the bottom of the skylight, and nail step flashing and roof shingles up each side of the skylight.
Cover the sash frame with aluminum counter-flashing. Install head flashing and cover with roofing felt, then replace the remaining roof shingles.
![installing the flashing and weatherproofing of the skylight on the roof](https://s42814.pcdn.co/wp-content/uploads/2019/12/skylight_07.jpg.optimal.jpg)
Step 5: Interior Finishing
With the exterior installation complete, you can finish the interior. Cut and install a 2-by-12 header above the skylight, ensuring it’s parallel to the floor. Cover the viewing shelf with 1/2-inch plywood followed by drywall.
![finishing the interior of a skylight by installing a wood header](https://s42814.pcdn.co/wp-content/uploads/2019/12/skylight_10.jpg.optimal.jpg)
Finish the exposed framing around the skylight with drywall. Apply metal corner bead, paper tape, and joint compound to the drywall. Paint the finished surfaces to match your interior.
![drilling drywall into the interior of the skylight](https://s42814.pcdn.co/wp-content/uploads/2019/12/skylight_12.jpg.optimal.jpg)
Maximizing Energy Efficiency With a Skylight
Energy-efficient skylights help reduce heating and cooling costs while providing ample natural light. Choose Energy Star-certified skylights with low-emissivity (low-e) coatings to minimize heat gain and loss. Look for double- or triple-pane glass options with argon or krypton gas fills for improved insulation. Use spray foam insulation or fiberglass batts to fill any gaps between the skylight frame and the rough opening.
For more energy efficiency, install shades or blinds designed for skylights. Automated systems that open and close based on sunlight help regulate indoor temperature effectively.
Calculating your potential energy savings can provide a clearer picture of your skylight’s long-term cost benefits. Some energy-efficient skylights may qualify for federal tax credits or local incentives. Check with your local government or energy provider for current offers.
Routine Skylight Cleaning Tips
Clean your skylight at least twice per year using a soft cloth or sponge and a mild, nonabrasive cleaner. Avoid using harsh chemicals or materials that could damage the glass or frame. Regularly inspect the skylight for any debris or obstructions that need to be cleared.
Watch for signs of leaks, condensation, or seal failure. Address any issues promptly to prevent water damage or energy loss. Monitor that the flashing remains intact and that there are no visible gaps around the skylight frame.
Meeting Building Regulations for a New Skylight
Check with your local building department for specific requirements regarding skylight installation, including egress regulations for habitable spaces. Meet all the local building codes to avoid potential fines and ensure your installation is safe.
Always use proper safety equipment, including a harness, when working on your roof. If you’re uncomfortable with heights or lack experience, hire a professional. Never work on the roof alone, and always check that your tools are securely fastened.