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How-To Install a Tubular Skylight or Light Tunnel

Construction How-To, Lighting, Windows & Doors September 20, 2006 Sonia


By Monte Burch

 

Tubular skylights bring natural light indoors.

 

 

 

 

Roof mounted skylights have been used for many years to bring the sun into our buildings, and a wide range of skylights are available. These days, tubular skylights can capture more sun than traditional skylights, even for small areas, and also provide more versatility. These units are also a basic do-it-yourself project and are available in a wide range of sizes and brands, such as Velux, Solatube, Sun-Dome, Sun Pipe and Sun-Tek.

While many skylights are more complicated, you can install a sun tube, such as the Sun-Tek Sun Tube shown in this article, in less than an afternoon. Instructions and everything you need come with the kit, including special leak-proof roof sealant. Sun-Tek’s tubes consist of three parts, a sun-dome for the roof, a tube to channel the light, and a diffusing system to disperse the light evenly.

As many have discovered, a simple skylight is often not the answer. It can provide light, but the light intensity changes with the amount and direction of the sun. You can have a “hotspot” of light on bright sunny days. Sun tubes eliminate this problem, providing evenly dispersed light throughout the area. And, they can also be used to direct light down through an attic and into a small area, such as a narrow hallway, even a dressing closet. They can also be used to provide natural light in a bathroom, and still maintain privacy.

The first step in installation is to mark the opening for the cut-out. Measure carefully, making sure the opening is square, then drive screws up through the roof sheathing and shingles at each corner of the opening.

The first step in installation is to mark the opening for the cut-out. Measure carefully, making sure the opening is square, then drive screws up through the roof sheathing and shingles at each corner of the opening.

 

A Close Look at the Tube

The Sun-Tek’s tubular skylights are available as single units, with tube sizes of 10, 14 and 21 inches and with tube length ranging from 10 to 30 feet, depending on the unit chosen. They can illuminate an area of 150 to 450 square feet. The one-piece seamless construction of the tube creates a completely leak-proof unit, and the exterior dome is made of super-tough polycarbonate that is impervious to hail and tree branches. The dome blocks 99-percent of damaging UV rays, so it is easy on carpeting and furniture. The tube is made of reflective aluminum to enhance reflectivity. Each unit comes with two elbows (15 inches in length when straightened) and one straight piece. Straight connectors are 22 inches long. In most instances additional straight connectors are needed. Also included in each kit is the diffuser lens, one tube of STS 1000 Sun-Tek butyl sealant, 10 yards of generic duct tape, and a galvanized steel (22-inch gauge) roof collar that can be used by the homeowner in the event they cut the roof opening too large. Extension connectors are available, as well as light kits that allow you to use the units for night-time lighting.

The company also offers multiple-tube units, called Sun-Tek Spyder Systems, which are available with two or four tubes and a single dome skylight. These are more complicated to layout and design, as well as to install. However, they do allow for much more dispersal of light by spreading out the tubes and diffuser. For instance the Model Quad 10-inch provides four tubes, each with light capabilities of 150 square feet.