Solar tube leak repair starts with one question: is the water coming from outside, or forming inside the tube? Tubular skylights often drip from condensation that has nothing to do with the roof. When the leak is real, the cause is usually the flashing around the base, the dome or its seal, or shingles that weren't worked in around the unit correctly.
If your solar tube is dripping, call Cannon Roofing at (940) 627-1045, day or night, or tell us about it on our contact page.
How a solar tube is put together
A tubular skylight has three main parts: a clear dome on the roof, a reflective tube that runs through the attic, and a diffuser lens in the ceiling. The dome sits on a flashing base that is fitted into the shingles, with the upper part of the flashing tucked under the shingles above and the lower part lying over the shingles below. The tube sections are joined and taped, and many are wrapped with insulation where they pass through the attic.
Each of those joints is a place water can get in, or moisture can form.
Condensation or a true leak?
Getting this right first saves you from roof work that won't help.
Signs of condensation
- Drips or fogging with no rain, often on cold mornings
- Water beading on the inside of the diffuser or tube walls
- Problems worst in bathrooms, kitchens or laundry rooms where indoor humidity runs high
- An uninsulated tube running through a cold or very hot attic
Condensation happens when warm, moist indoor air meets a cold tube surface. In North Texas winters, the attic can be much colder than the room below, and the tube becomes a cold pipe running between them.
Signs of a true leak
- Drips that start during rain or right after it and stop in dry weather
- Water stains on the attic deck or insulation around the outside of the tube
- Leaks that get worse with wind from one direction
- A cracked, loose or hail-damaged dome visible from the ground
A simple way to tell them apart
Keep a short log for a couple of weeks: date, weather, time of day and whether water appeared. If drips line up with cold mornings and steamy showers, it's condensation. If they line up with rain, it's the roof or the unit.
Why solar tubes leak from outside
Flashing and shingle problems
The most common cause is the base. If the upper flashing sits on top of the shingles instead of under them, water runs straight beneath it. Relying on sealant instead of correct lapping works only until the sealant dries out. Nails through the flange can back out, and debris piling up on the upslope side can dam water against the base.
Dome failures
Hail can crack or craze plastic domes, and years of Texas sun make them brittle. The gasket or seal between the dome and the flashing base can shrink, split or shift, and fasteners holding the dome can loosen.
Tube joint issues
Tape at the tube joints can let go over time, letting condensation or small leaks run down the outside of the tube and appear at the ceiling ring, far from the real source.
Solar tube leak repair options a roofer uses
Once the cause is confirmed, the repair follows from it:
- Reset the flashing. The shingles around the base are lifted, the flashing is repositioned so it laps correctly, damaged shingles are replaced and fasteners go in the right spots.
- Replace the dome or seal. A cracked dome or failed gasket is swapped with a compatible part where one is available.
- Re-tape and insulate the tube. Joints are resealed and an insulated sleeve is added in the attic to cut condensation.
- Replace the unit. Older tubes with brittle domes and failing bases are often best replaced with a new unit and flashing kit, especially during a reroof.
For condensation, the fix is inside: insulating the tube, running bathroom exhaust fans longer and keeping humidity in check.
Solar tube repairs with Cannon Roofing
Our roof repair crews diagnose tubular skylight leaks from both sides, checking the dome, flashing and surrounding shingles on the roof and the tube, joints and insulation in the attic. You'll know whether you're dealing with a leak or condensation before any work is quoted. For conventional skylights, see our guide to skylight leak repair.
Cannon Roofing has been a Decatur roofing company since 1994. Our factory-trained technicians all carry the Technician Seal of Safety, so each one is background checked, drug tested and insured. We provide a free inspection and estimate, and our emergency line is open 24/7.
Frequently asked questions
Can I fix a leaking solar tube with caulk?
Caulk around the base can slow a leak briefly, but it won't correct flashing that is lapped the wrong way, and it can trap water under the shingles. A proper repair lifts the shingles and resets the flashing.
Should I remove my solar tube when I replace my roof?
Not necessarily. Many units can be removed and reinstalled with new flashing during a reroof. If the dome is brittle or the base is worn, replacing the unit at the same time usually makes more sense.
Why does my solar tube only drip in winter?
That pattern points strongly to condensation. Warm indoor air meets a cold tube in the attic and forms water. Insulating the tube and lowering indoor humidity usually solves it.
Want to know whether your solar tube is leaking or just sweating? Call Cannon Roofing at (940) 627-1045, we answer 24/7, and we'll inspect it from the roof and the attic, show you what we find and recommend the right fix. You can also reach us through our contact page.