Why can the ceiling look fine while the wall behind it is soaked?
Water runs along the framing and down inside the wall cavity before it reaches the surface of the ceiling or the wall. The paint can look sound while the insulation and the framing below it hold water, because the finish is the last thing the water reaches.
A wet cavity is typically dark and cold when you touch the wall, and it can smell damp even when the room looks dry. A moisture reading inside the cavity is the only dependable test, and the crew takes it from the attic side and, where needed, through a small opening in the wall.
Water in a wall cavity also drains down to the bottom plate and onto the floor below. The crew checks the bottom of each wall in the room below the leak, so the path is followed to its end and not stopped at the first stain.
Can I climb into the attic to look for the leak myself?
You can look from the attic hatch with a torch, but do not walk on the attic floor without boards across the joists, and do not go onto the roof. The insulation hides the joists, and a foot can go through the ceiling below. Look, photograph and report what you see.
The most useful things to note from the attic are the wet insulation, the dark stains on the sheathing or rafters and the position of any gap in the roof boards. Note where the wet area sits relative to the chimney, the vents and the edges of the roof, because those points are the usual suspects.
Do not disturb the insulation or push a stick into it to find the water. Describe what you see to the line and let the crew access the attic safely, because that avoids spreading wet material across the ceiling below.
Does the roof need to be repaired before the house can be dried?
The entry point should be closed before the drying is finished, because drying with an open roof means more water will keep coming in. A temporary cover is often the first step, and the permanent repair is made by a roofer after the crew has recorded the damage.
The crew does not repair the roof itself, but it tells you when water is still entering. A leak that keeps running after the attic is dry means the entry point has not been closed, and the drying plan cannot finish until it has been.
A roofer should carry out any permanent repair. The Municipality's permitting rules may apply to roof work, so ask the roofer whether a permit is needed. The crew's written record of the entry point and the damage is useful to the roofer and to the insurer.
What happens to a ceiling that has been wet for days?
A ceiling that has been wet for days can sag, separate from its fixings or stain through in a way that shows a clear tide line. Plaster that is soaked can crack and fall, and drywall loses its strength when wet, so the crew assesses the ceiling before anything is done to it.
Drywall that is soaked is removed and replaced rather than dried, because the paper facing and the gypsum core lose their strength and their shape. Plaster on lath can sometimes be dried in place if it is sound, but the crew tests it by pressing gently and checking whether it moves or cracks.
The ceiling is repaired after the framing has been confirmed dry. Repairs to the finish, such as paint, texture and the ceiling itself, are a separate scope that is explained and approved once the building is dry.
How does snow and ice on the roof affect a leak?
Snow that melts on a warm part of the roof and refreezes at the cold eave can build up enough ice to force water back under the covering. The water then runs in at the eave and down the outside wall, where it often goes unnoticed until the stain reaches the room.
The leak often appears at a point the owner did not expect, such as a corner of the room under the eave or a wall that faces the snow. The crew checks the eave and the top of the outside wall first, because that is where the water tends to enter in a thaw.
Clearing snow from the eaves, keeping the attic ventilated and sealing gaps around the penetrations all reduce the chance of this kind of leak. A roofer or a contractor who works on the attic can advise on what applies to the house.
