A 10-inch solar tube suits smaller rooms, and a 14-inch tube suits larger rooms and longer tube runs. Solatube rates its 10-inch model for spaces up to 200 square feet and its 14-inch model for spaces up to 300 square feet, and Lyons Roofing says a 14-inch tube delivers approximately 50 percent more light. Length and bends reduce output somewhat, so the right size depends on the room, the run from roof to ceiling, and the roof type. Lyons Roofing has served Arizona roofs since 1993, licensed under AZ ROC# 348074, with general liability and workers compensation coverage on every project. The BBB has awarded us its Ethics Award and an A+ rating, reflected in our active A+ BBB accreditation for our Phoenix office and A+ BBB accreditation for our Tucson office. Angi recognizes us as a top-rated, repeated Super Service Award winner through our top-rated Phoenix Angi profile and top-rated Tucson Angi profile. Thousands of verified five-star reviews appear on our Phoenix Google reviews and Tucson Google reviews. As an ARCA member in good standing, we meet the industry standards governing professional roofing in Arizona. We install solar tubular lights on tile, shingle, flat, and foam roofs, so call 602-638-3135 (Phoenix) or 520-900-1442 (Tucson) to size a solar tube for your home.
What Is a Solar Tube, and Why Does Size Matter?
A solar tube, also called a tubular skylight or sun tunnel, is a roof-mounted dome and a reflective tube that carries daylight into a room. The Whole Building Design Guide’s light tube technote describes the parts: a transparent, UV- and impact-resistant dome with a flashing base, the tube itself, and a ceiling-level diffuser assembly that transfers sunlight to the interior.
Diameter sets how much daylight reaches the room. The same technote lists Solatube in 10-inch, 14-inch, and 21-inch sizes and says each tube needs a circular opening in the roof of 9 to 21 inches. Velux offers its Sun Tunnel in 10-inch and 14-inch diameters, with a 22-inch size used mainly for commercial work, so 10 and 14 inches are the two sizes most homeowners compare.
10-Inch vs 14-Inch Solar Tube at a Glance
| Feature | 10-Inch Tube | 14-Inch Tube |
|---|---|---|
| Solatube model (example) | 160 DS | 290 DS |
| Tube diameter | About 10 inches (250 mm) | About 14 inches (350 mm) |
| Rated room size | Spaces up to 200 square feet | Spaces up to 300 square feet |
| Light coverage area | About 150 to 200 square feet | About 250 to 300 square feet |
| Potential tube length | About 20 feet | About 30 feet |
| Lyons Roofing guidance | Suits smaller rooms such as bathrooms, closets, and laundry rooms | Delivers approximately 50 percent more light and suits larger spaces |
The figures come from Solatube’s 160 DS product and 290 DS product. Lyons Roofing installs solar tubular lights from Solatube and other proven brands, so ratings for another brand may differ.
How Much More Light Does a 14-Inch Tube Give?
Lyons Roofing’s solar tubular lights say a 14-inch tube delivers approximately 50 percent more light than a 10-inch tube. Solatube’s coverage ratings show a similar step at the top of each range, from up to 200 square feet for the 160 DS to up to 300 square feet for the 290 DS.
Geometry tells a different story. A 14-inch opening has about 1.96 times the area of a 10-inch opening, because area grows with the square of the diameter. The rated coverage area grows more slowly than the opening, so use the coverage rating, not the dome diameter, to size a room, and let an installer confirm the fit.
Which Size Fits Which Room?
Sizing guides agree on the general pattern and differ at the margins. This table compares what each source says:
| Source | 10-Inch Guidance | 14-Inch Guidance |
|---|---|---|
| Solatube (160 DS and 290 DS) | Spaces up to 200 square feet; coverage about 150 to 200 square feet | Spaces up to 300 square feet; coverage about 250 to 300 square feet |
| Solatube Australia (metric ratings) | About 19 square meters, roughly 205 square feet | About 28 square meters, roughly 300 square feet |
| A Texas Hill Country roofing contractor | Rooms under 150 square feet | Rooms of 150 to 300 square feet |
| Lyons Roofing | Smaller rooms such as bathrooms, closets, and laundry rooms | About 50 percent more light for larger spaces |
Solatube Australia’s sizing blog adds two practical rules: choose the larger unit if your room falls between sizes, and expect that the shape of the room and the dome’s position on the roof affect the result. It also notes that its estimates assume the dome sits in the direct path of the sun.
- Bathrooms, closets, laundry rooms, and hallways: Lyons Roofing points to a 10-inch tube for these smaller spaces.
- Rooms near 150 to 200 square feet: The guides overlap here, so measure the room and the tube run before you decide.
- Rooms from 200 to 300 square feet: Solatube’s 14-inch model is rated for this range.
- Larger spaces: Some installers use more than one tube for a larger room, and a roofer can compare layouts.
Tube Length, Bends, and Ceiling Height
Light loses strength as it travels. Lyons Roofing notes that tube length and bends reduce output somewhat, and Solatube Australia says there will be some loss of light the longer the tubing, so it is probably better to choose the larger unit when the tube spans a long distance.
The coverage figures also assume a typical setup. Solatube Australia states that its estimates assume an average tube length of 1.82 meters (about 6 feet) and a ceiling height of 2.4 meters (about 8 feet). Solatube lists a potential tube length of about 20 feet for the 160 DS and about 30 feet for the 290 DS, so a long run is possible but trims the light the room receives.
Sizing a Solar Tube?
Roof-Matched Flashing | Workmanship Guarantee | AZ ROC# 348074 | Call 602-638-3135 (Phoenix) or 520-900-1442 (Tucson)
Which Roofs Can Take a Solar Tube?
Lyons Roofing installs solar tubular lights on tile, shingle, flat, and foam roofs. The roof type decides how the installer flashes the dome, and the flashing is what keeps the penetration watertight.
| Roof Type | What the Installer Matches | Related Lyons Service |
|---|---|---|
| Tile | Flashing made for tile, since Lyons notes that leaks often come from generic flashing on tile roofs | Residential tile roof repairs |
| Shingle | Flashing and waterproofing matched to the shingle roof at the penetration | Residential shingle roof repair |
| Flat | A membrane-compatible flashing base that works with the existing waterproofing layer | Residential flat roof repair |
| Foam | A membrane-compatible flashing base that works with the existing waterproofing layer | Spray foam roofing |
If you are weighing a solar tube against a skylight, our guide to alternatives to skylights compares the two, and our skylight installation and repair covers the other option. Our post on the benefits of solar tube lights lists the tradeoffs, including no light after dark and no sky view or ventilation, and our guide to skylights and solar tubes during roof installations explains why a new roof is a natural time to add one.
Permits, Flashing, and Leak Prevention
A solar tube cuts a hole in the roof, so the permit and the flashing both matter. Tucson’s permit exemptions says that installing skylights, light tubes, or new roof vents requires a permit and that penetrations must be flashed and sealed per building code. The City of Phoenix guide How to Obtain a Residential Building Permit (Rev. 2/20) does not address light tubes, so ask your city’s building department before work starts, because rules change.
Leaks trace to the installation, not the size. Our post on whether solar tubular lights are prone to leaking says they should not leak when installed correctly and maintained well, and lists improper installation, weather or storm damage, aging lights, and old roofing as the usual causes. It advises hiring an experienced, licensed roofer, and the Lyons solar tube page adds that each installation includes proper flashing and waterproofing at the roof penetration.
If you already have a skylight that leaks, our post on what to do about a leaking skylight explains how to rule out condensation, check the glass seal and the flashing, and decide when to call a roofer.
DIY vs. Professional: What You Can Measure and What Needs a Roofer
| Task | Homeowner | Professional Roofer |
|---|---|---|
| Measure the room | Yes | Yes, with the room shape and dome position in mind |
| Estimate the tube run from roof to ceiling | Partly, if the attic is safely reachable | Yes, including any bends |
| Match the size to a coverage rating | Yes, using the table above | Yes, and confirm it against site conditions |
| Cut the roof opening and flash and seal the dome | No, since NRCA recommends that an experienced roofing contractor handle roof system repairs | Yes, with flashing matched to the roof material |
| Check the permit requirement | Yes, with the city | Yes |
| Inspect the dome and flashing after storms | From the ground or a window | Yes, with a hands-on check |
NRCA does not recommend that homeowners or property management personnel attempt roof system repairs and recommends retaining an experienced roofing contractor. A new roof penetration changes the waterproofing in the same way, which is why we treat a solar tube as roof work, not a ceiling fixture.
How to Choose Your Solar Tube Size in Six Steps
- Measure the room. Multiply length by width to get square footage.
- Note the room’s purpose. Bathrooms, closets, laundry rooms, and hallways point to a 10-inch tube, and larger living spaces point to a 14-inch tube.
- Estimate the run. Measure from the roof deck to the ceiling and count any bends, since both reduce light.
- Compare the coverage rating. Use the manufacturer’s published figure for the specific model, and choose the larger unit if the room falls between sizes.
- Confirm the roof type. Tile, shingle, flat, and foam roofs each need flashing matched to the material.
- Check the permit. Ask your city’s building department, and have a roofer confirm the size and placement on site.
A residential roof inspection before installation confirms the condition of the roof around the planned opening, and a solar attic fan from the same crew can pair with a tube when the attic also needs ventilation.
What Arizona Sun, Heat, and Monsoons Mean for a Solar Tube
Arizona has plenty of daylight to carry. July sunshine averages reach 85% of daylight hours in Phoenix and 78% in Tucson, and December sunshine averages still reach 77% in Phoenix and 79% in Tucson. Solatube Australia notes that in winter, when the sun sits lower in the sky, you might want a larger option.
Heat is the other half of the question. Phoenix averaged 111 days a year at or above 100 degrees from 1991 to 2020, and summer 2026 ranked as the second hottest on record in Phoenix, averaging 97 degrees. Our guide on whether skylights make your home hotter in the summer says skylights can warm a home in the Southwest, while our solar tube guidance describes tubes as bringing in daylight without that added heat.
Monsoon rain tests the flashing. Sky Harbor finished the 2026 monsoon at 2.48 inches against a 2.43-inch normal, and NWS normals show Tucson receiving about 5.5 of its roughly 10.6 inches of annual rain in July through September, per the Tucson monthly normals. A dome that is flashed for the roof material, and a crew that stands behind the work, matter more in those months than the diameter.
Why Arizona Homeowners Choose Lyons Roofing
| What We Offer | What It Means for Your Solar Tube Project |
|---|---|
| A+ BBB Ethics Award, Phoenix roofing office | BBB Ethics Award winner, A+ rated, independently verifying honest, professional service |
| A+ BBB Ethics Award, Tucson roofing office | Both Arizona locations hold active A+ BBB accreditation and Ethics Award recognition |
| Top-rated Phoenix Angi profile, Repeated Super Service Award | Super Service Award recognition across the Phoenix metro for consistently high-quality roofing |
| Top-rated Tucson Angi profile, Repeated Super Service Award | Award-winning service recognition across both our Phoenix and Tucson roofing markets |
| Phoenix Google reviews, thousands of verified 5-star ratings | Among the most-reviewed roofing contractors in Arizona based on verified customer feedback |
| Tucson Google reviews, verified 5-star ratings | Consistent 5-star feedback from customers in both Arizona markets |
| ARCA member in good standing | Compliant with ARCA standards for installation, safety, and professional roofing conduct in Arizona |
| GreenSky financing available | Flexible financing options for property owners managing roofing project budgets |
| Licensed Under AZ ROC# 348074 | State-verified license, active and in good standing, verifiable at roc.az.gov |
| Fully Bonded and Insured (GL + Workers Comp) | Zero liability exposure for property owners, every project fully covered |
| In Business Since 1993, 30+ Years | Three decades of experience with Arizona roofing systems in extreme desert conditions |
| Manufacturer Certified Installers | Work performed to manufacturer specifications, helping protect material warranties |
| Free Inspections and Written Assessments | A written assessment of your roof before any solar tube work begins |
| 24/7 Emergency Response | Available any time for roofing emergencies throughout our Arizona service area |
Frequently Asked Questions: Solar Tube Sizes in Arizona
What is the difference between a 10-inch and a 14-inch solar tube?
The differences are diameter, light output, and the room size each can serve. Solatube rates its 10-inch 160 DS for spaces up to 200 square feet and its 14-inch 290 DS for spaces up to 300 square feet, and Lyons Roofing says a 14-inch tube delivers approximately 50 percent more light. The 14-inch model also lists a longer potential tube run, about 30 feet against about 20 feet.
Which size is best for a bathroom, closet, or laundry room?
Lyons Roofing says a 10-inch tube suits smaller rooms such as bathrooms, closets, and laundry rooms, and it lists hallways among typical candidates for a solar tube.
How large a room can a 14-inch solar tube light?
Solatube rates its 14-inch 290 DS for spaces up to 300 square feet, with a light coverage area of about 250 to 300 square feet. Room shape, dome placement, tube length, and bends affect the result, so an installer should confirm the fit for your room.
How much more light does a 14-inch tube give than a 10-inch tube?
Lyons Roofing says approximately 50 percent more. Solatube’s published coverage figures show a similar step at the top of each range, from up to 200 square feet for the 160 DS to up to 300 square feet for the 290 DS. A 14-inch opening has about 1.96 times the area of a 10-inch opening, but the coverage rating is the better guide for choosing a size.
Should I choose the larger size if my room falls between two sizes?
Solatube Australia suggests the larger unit when a room falls between sizes and when the tube spans a long distance. The installer’s measurements at your home make the final call.
Can I install two 10-inch tubes instead of one 14-inch tube?
Some installers use multiple tubes for a larger room. Two tubes mean two roof openings to flash and seal, so a roofer can compare the layouts for your room and roof type before you decide.
How long can a solar tube run be, and do bends matter?
Solatube lists a potential tube length of about 20 feet for the 10-inch 160 DS and about 30 feet for the 14-inch 290 DS. Lyons Roofing notes that length and bends reduce light output somewhat, and Solatube Australia notes some loss of light the longer the tubing runs, so a shorter, straighter run delivers more light at any size.
Which roof types can take a solar tube?
Lyons Roofing installs solar tubular lights on tile, shingle, flat, and foam roofs. Flat and foam installations use a membrane-compatible flashing base that works with the existing waterproofing layer.
How long does a solar tube installation take?
Lyons Roofing states that most residential solar tube installations are completed in two to four hours per unit.
Do solar tubes need a permit in Arizona?
It depends on the city. Tucson’s permit exemptions page says installing skylights, light tubes, or new roof vents requires a permit and that penetrations must be flashed and sealed per building code. The City of Phoenix residential permit guide does not address light tubes, so ask your city’s building department before work starts.
Do solar tubes leak?
Lyons Roofing says solar tube lights should not leak when installed correctly and maintained well, and that leaks usually trace to improper installation, weather or storm damage, aging lights, or old roofing past its lifespan. Lyons also notes that leaks often come from flashing that was not made for the specific roofing material, especially generic flashing on tile roofs.
Do solar tubes add heat in summer?
Lyons Roofing’s guides describe solar tubes as bringing in daylight without the added heat of skylights or windows. A Whole Building Design Guide technote adds that light tubes can help save cooling energy by reducing the need to remove heat from electric lighting, with actual results depending on climate.
Do solar tubes work at night?
No. Lyons Roofing notes that solar tubes provide no light after dark and no sky view or ventilation, so they work as a daytime light source.
What warranty comes with a Lyons Roofing solar tube installation?
Lyons Roofing states that the solar tube unit carries a manufacturer warranty and that its workmanship guarantee covers the roofing and flashing at the dome penetration.
How do I schedule a solar tube installation with Lyons Roofing?
Request an installation through the Lyons Roofing website or call our office. Our teams serve Phoenix, Tucson, and the surrounding communities, and installations include proper flashing and waterproofing to prevent leaks at the roof penetration.
When to Call Lyons Roofing
Call when you are choosing between sizes, when the tube run is long or bent, or when your roof is tile, flat, or foam and you want flashing matched to the material. Lyons Roofing installs solar tubular lights with most installations completed in two to four hours per unit, and the unit carries a manufacturer warranty while our workmanship guarantee covers the roofing and flashing at the dome. You can verify our license with the Arizona Registrar of Contractors, and if water is entering your home, our emergency roof service responds any time, day or night, at 602-638-3135 (Phoenix) or 520-900-1442 (Tucson).
Book Your Solar Tube Installation
AZ ROC# 348074 | Bonded and Insured | Workmanship Guarantee | Call 602-638-3135 (Phoenix) or 520-900-1442 (Tucson)