A stain with no rain: probably not the roof
If it is a pipe or an AC drain it is still running, and the EPA's 24 to 48 hour drying window applies to whatever is already wet.
What is probably happening
- A plumbing leak: a supply line, a toilet seal or a shower pan above the stain.
- An air conditioner in the attic with a blocked condensate drain or a rusted drain pan. This is common in summer.
- Condensation in the attic in cold weather, dripping off nails or ducts, which looks exactly like a leak.
- An old roof leak that has already dried, leaving a brown ring that is not growing.
Do this in the next five minutes
- Press the stain. Damp means active. Dry and not growing means an old event.
- Mark the edge of the stain with a pencil and date it so you can see if it grows.
- Check what is directly above: a bathroom, a water heater, an attic air handler. Run each fixture and watch.
- Look in the attic with a flashlight for a wet spot, a full drain pan, or frost and drips on the underside of the roof deck.
- If it is wet and there is a fixture above, shut the water off to that fixture and call a plumber.
- If it is the AC pan, switch the system off at the thermostat and call an HVAC company.
Do not
- Do not book a roofer first for a dry-weather stain. A roof leak needs rain or melting snow to run.
- Do not paint over a stain that is still damp. It will come back and you will have lost the evidence.
- Do not ignore attic frost or damp insulation in winter. That is warm indoor air leaking into the attic, the same problem that causes ice dams.
Who to call
A licensed plumber, or an HVAC company if it is the AC
A roofer can only fix rain. If nothing has come from the sky, the water came from a pipe, an appliance or condensation.
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What it should cost
$75 to $600
A roof inspection to rule the roof in or out, national range
Source: Angi, roof repair cost, updated August 2026. View source
National published range, not a quote for your job. The full cost table for this trade is on the plumbing page.
Ask this contractor, on the phone, before anyone comes out
Tap each one as you ask it.
- What is directly above this stain in my house, and have you checked that first?
- Is the stain active or historic in your view, and how did you test that?
- If you find it is the roof after all, what does your inspection fee cover?
End the call if
- A roofer who quotes a roof repair for a stain that has never grown in rain.
- Anyone who suggests a whole roof replacement from a single ceiling stain without an attic inspection.