Your roof is leaking right now: what to do in the first hour
The first hour is about limiting damage and gathering evidence, not about fixing the roof. Almost nothing useful happens up there in the rain.
Water is coming through the ceiling and the instinct is to stop it at the source. Resist that. In active rain, in the dark, or on a wet slope, going up is the single most dangerous thing you can do about this problem, and it is also the least effective — you cannot find an entry point on a roof that is running with water. The first hour has three jobs, and all three happen indoors or from the ground.
1. Deal with the water inside
Move what can be moved, and put a container under the drip. If the ceiling is bulging or sagging, that is a pocket of trapped water sitting on the back of the drywall, and it is heavier than it looks. A full bulge can bring down a sheet of plasterboard in one piece. The counter-intuitive but correct move is to relieve it deliberately: put a bucket underneath and pierce the lowest point of the bulge with a screwdriver so it drains in a controlled stream rather than collapsing. A small hole you made is a much cheaper repair than a ceiling that came down on its own.
If water is anywhere near a light fitting, a ceiling fan, or a socket, turn that circuit off at the panel before you go near it. Water tracks along the top of the ceiling and drops through whatever opening it finds, and a light fixture is an opening.
2. Find out what is above the wet spot
This is the part that actually saves you money, and it happens in the attic with a flashlight. The stain on the ceiling is where the water gave up; it is often several feet from where the water arrived, because it will run along a rafter or along the top of the insulation until something interrupts it.
Go up into the attic and look at the underside of the roof deck above and uphill of the wet area. You are looking for a wet trail, a shiny run mark on the timber, a dark patch on the plywood, or daylight. Follow it as far up the slope as it goes. What you want to end up with is the answer to a single question: what is directly above that point on the outside? A chimney, a skylight, a plumbing vent pipe, a valley, a wall junction, or nothing at all.
That answer is worth more than anything else you can collect, because it tells you which of the flashing details is the suspect — and because roofs very rarely leak through the middle of a clear slope.
3. Work out who you are calling
Not every ceiling leak is a roofer's job, and calling the wrong trade costs you a visit.
If water appears only when it rains, it is the roof. If it appears when somebody upstairs uses water and never otherwise, it is plumbing. If it appears on cold mornings with no rain for days, it is very likely condensation in the attic, and a roofer will find nothing wrong because nothing is wrong with the roof. If it appears during a thaw after snow, it is probably an ice dam, which is a heat problem wearing a roofing costume.
Take photographs while everything is still wet. Note the date, the weather, and whether there was wind and from which direction — wind-driven rain gets into things that ordinary rain never reaches, and a leak that only happens in a storm from one particular direction is a strong clue.
The temporary cover
A tarp over the affected area is the standard emergency measure and it is genuinely useful, but it belongs to somebody who does it for a living. Covering a roof means working on a slope, usually in bad weather, with a large sheet of plastic that behaves like a sail. This is exactly the situation that fall-protection rules exist for: professional roofers working at that height are required to have fall protection in place, and they have it because the risk is real and well documented. If a roof needs covering before it can be repaired, that is a call to make, not a Saturday project.
What not to do
Do not go up in the rain. Do not go up in the dark. Do not go up on a snowy or frosty roof at all. Do not squirt sealant into a suspected entry point from a ladder — sealant applied to the wrong side of a lap holds water against the joint instead of shedding it, and it makes the eventual proper repair harder and more expensive. And do not sign anything with somebody who knocked on your door offering to fix it today.
Frequently asked questions
Should I put a bucket under it or poke the ceiling?
Both, in that order. If the ceiling is bulging, put the bucket down first and then pierce the lowest point of the bulge so it drains in a controlled way. A bulge left alone can bring a whole sheet of drywall down, which is a much larger repair than the hole you made.
Can I find the leak from inside?
You can usually find the entry zone, which is what matters. Go into the attic with a flashlight and trace the wet run up the underside of the roof deck. The point where it stops going uphill tells you what is above it outside, and that is the information a roofer needs.
It is leaking but it hasn't rained. Is that possible?
Yes, and it is common. Warm humid air from the house condensing on cold roof sheathing can put enough water up there to soak a ceiling, and a hard freeze followed by a thaw releases it all at once. It looks exactly like a leak and no roof repair will fix it.
Is a tarp something I can put on myself?
We do not recommend it and we do not give instructions for it. Covering a roof means handling a large sail of plastic on a slope, usually in the weather that caused the problem. Professionals doing that work are required to use fall protection for a reason.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- NRCA. National Roofing Contractors Association
- US OSHA. 1926.501 — Duty to have fall protection (OSHA)