Your Ceiling Is LEAKING In Winter… But Your Roof Might NOT Be the Problem, by The Roof Lab on YouTube. 7 min 46 s.
- Video length
- 7 min 46 s
- Time to do it
- 2 to 3 hours
- Difficulty
- Medium
- Steps
- 10
What you need
Steps
Note when the stain appears. A ceiling mark that shows up in freezing weather or during a thaw, with no rain, points to attic condensation rather than a shingle leak.
Go into the attic on a cold morning and check the underside of the roof deck and the nail tips for frost or dark damp patches. Frost means moist air is condensing there.
Rule out an outside leak. Look for lifted or missing shingles, gaps around flashing and chimneys, and ice dams at the eaves. If those look fine, keep looking inside.
Trace the moisture. Check whether a bathroom or kitchen exhaust fan blows into the attic, and whether its duct is loose or disconnected. Air from the house is the usual source.
Seal ceiling holes with caulk or spray foam. Work around light fittings, the attic hatch, plumbing pipes and wires where they pass up into the attic.
Clear the soffit vents. Pull insulation back and fit rigid baffles so air can travel from the eaves to the ridge without being blocked.
Run exhaust ducts all the way outside through the roof or wall, using insulated duct, and tape every joint. Never let a fan dump warm wet air into the attic.
Top up the insulation to the level recommended for your climate zone. Keep it even, with no gaps and no compressed patches over joists.
Keep indoor humidity down in winter. Run exhaust fans during showers and cooking, and aim for about 30 to 50 percent relative humidity.
Before paying for a new roof, ask the contractor what evidence shows where the water comes from and how the repair stops that source.
Tips and common mistakes
Adding more roof vents alone rarely fixes condensation if warm air still leaks into the attic.
A stain that appears during a thaw was probably fed by frost that built up weeks earlier.
Step only on ceiling joists, wear a dust mask, and take a torch so you can see the far corners.
Check the attic hatch lid too, since a loose or unsealed hatch lets a lot of moist air through.
Questions
Will a new roof stop my ceiling leaking in winter?
Only if the water is coming from outside. If warm air from your house is condensing on the cold roof deck, new shingles will not change anything.
How do I know if it is an ice dam instead?
Ice dams form at the eaves when heat escaping into the attic melts snow that then refreezes. Water backs up under the shingles. Air sealing and insulation are the real fix.
Is frost on the roof deck normal?
A light trace on a very cold day can happen. Thick frost, dripping or damp insulation means too much moisture is getting into the attic.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
