A Comprehensive Guide to Velux Skylight Installation

Installing a Velux skylight is a transformative home improvement project that can flood your living space with natural light, improve ventilation, and even enhance your overall well-being. While the prospect is exciting, a successful Velux skylight installation requires careful planning, a clear understanding of the process, and a commitment to safety. This guide will walk you through everything you need to know, from initial considerations to the final finishing touches, ensuring your project is a resounding success.

The first and most critical step in any Velux skylight installation is planning and preparation. Rushing this phase can lead to costly mistakes and potential damage to your home. Begin by assessing your goals. Are you looking for more light, better air circulation, or a view of the sky? Your objective will influence the type of skylight you choose. Velux offers a range of models, including fixed skylights that do not open, and ventilating skylights that can be manual, solar-powered, or operated by remote control. Solar-powered models are particularly popular as they eliminate the need for complex electrical wiring.

Next, you must determine the ideal location for the skylight. This involves going into your attic and identifying the spacing between your roof rafters. Velux skylights are designed to fit standard rafter spacing, but if your rafters are non-standard, you may need to order a special size or plan for structural modifications. It is absolutely crucial to check for any plumbing vents, electrical wiring, or HVAC ducts that might be obstructing the chosen spot. Furthermore, consider the roof’s pitch and the direction the skylight will face. A north-facing skylight provides consistent, cool light, while a south-facing one will deliver abundant light and solar heat gain, which can be desirable in colder climates but may require a shade or blind in warmer regions.

Once you have a plan, the next phase is gathering the necessary tools, materials, and safety equipment. A proper Velux skylight installation is not a simple DIY task for a beginner; it requires confidence working on a roof and inside an attic space.

• Tools: Tape measure, level, utility knife, reciprocating saw or circular saw, drill/driver, hammer, pry bar, chalk line, and a staple gun.
• Materials: The Velux skylight unit itself, the corresponding flashing kit (this is essential for a watertight seal), roofing nails/screws, and insulation.
• Safety Gear: This is non-negotiable. You will need a sturdy extension ladder, a certified roof harness system anchored to a secure point, safety glasses, gloves, and durable work boots.

Before making any cuts, it is wise to contact your local building department to inquire about necessary permits. Skylight installation often requires a permit to ensure the work meets building codes related to structural integrity and weatherproofing.

The actual installation process can be broken down into distinct stages. Remember, if at any point you feel unsure, it is best to stop and consult a professional roofing contractor. A Velux skylight installation is only successful if it is watertight and structurally sound.

1. Creating the Opening from Inside: From the attic, carefully mark the intended opening on the roof sheathing, ensuring it is centered between the rafters. Use a drill to create pilot holes at each corner from the inside out. These holes will be your guides on the roof.
2. Preparing the Roof: Safely ascend to the roof with your harness secured. Snap chalk lines between the pilot holes to outline the cut. Using your saw, carefully cut through the shingles and roof sheathing along the lines. Remove the cut section of sheathing and shingles.
3. Cutting the Rafters (if necessary): If the skylight width requires it, you may need to cut one or more rafters. This is a critical structural step. You must install double headers (strong horizontal supports) above and below the skylight opening to redistribute the load. This is a step where professional help is highly recommended.
4. Installing the Curb or Mounting the Frame: Some Velux models are designed for curb mounting, where a wooden frame (curb) is built first, while others are direct-to-deck mounted. Follow the manufacturer’s instructions precisely. For a curb-mounted skylight, the curb must be perfectly level and square before it is securely fastened to the roof deck.
5. Applying the Flashing: The Velux flashing kit is a multi-part system designed to integrate seamlessly with your roof. It typically consists of a bottom apron, side flashing, and a top flashing that sits under the shingles above the skylight. Each layer must be installed in the correct order and sealed properly according to the instructions. This is the most important step for preventing leaks.
6. Setting the Skylight: Once the curb and flashing are prepared, the skylight unit is carefully placed onto the curb. It is then secured with the provided fasteners. Ensure the unit is level and operates smoothly if it is a venting model.
7. Finishing the Interior: Back inside the attic, you will need to frame the rough opening with lumber to create a shaft (or lightwell) that directs the light down into the room. This shaft must be properly insulated and vapor-barriered to prevent heat loss and condensation. Finally, the interior drywall is installed and finished, and the optional pre-fabricated Velux trim kit is attached for a clean, professional look.

Even with meticulous planning, you may encounter challenges during your Velux skylight installation. One common issue is discovering rotten roof decking once the shingles are removed. This must be repaired before proceeding. Another challenge is unexpected rain. Always check the weather forecast and have a heavy-duty tarp on hand to cover the opening overnight. Condensation can also be a concern; proper insulation and ventilation around the skylight shaft are key to mitigating this. If your roof has a very steep pitch or is made of a material like clay tile or slate, the complexity of the installation increases significantly, and hiring a professional is strongly advised.

For those who prefer to leave it to the experts, hiring a certified Velux installer is an excellent option. These professionals are trained specifically in Velux skylight installation and are familiar with the products and best practices. They can often handle the entire process, including obtaining permits, and typically offer warranties on their workmanship, providing valuable peace of mind.

A well-executed Velux skylight installation is more than just a home upgrade; it is an investment in your quality of life. The influx of natural light can make rooms feel larger and more inviting, reduce reliance on artificial lighting during the day, and has been shown to boost mood and productivity. By thoroughly planning your project, prioritizing safety, and following precise installation steps, you can successfully add this beautiful and functional feature to your home. Whether you tackle it yourself or hire a pro, the result will be a brighter, more airy living space for years to come.