The short answer
A roof needs prompt repair when water is getting in or the structure is shifting. The clearest signs are missing or slipped tiles, damp stains or drips on ceilings, daylight visible through the roof from the loft, and a sagging ridge or slope. Moss, faded colour and general weathering are signs of age, and they can usually wait for a planned survey.
Missing, slipped or broken tiles and slates
The most obvious sign is visible from the street. A gap in the covering, a tile sitting proud of its neighbours, or fragments on the ground after a windy night all mean the layer beneath is now doing the work of keeping out the rain. That layer is the underlay, a sheet laid under the battens, and it is designed as a back-up and not as the main defence.
One slipped slate or tile is a small job. It becomes more pressing when it sits above a valley, a chimney or a bedroom, because rain then has a short path to the timbers. Several tiles slipping in the same area can point to failing fixings, and our page on how a slipped tile is fixed explains the repair. Take photographs from the ground rather than climbing up for a closer look.
Cracked tiles are easy to overlook. A crack lets water through slowly, and it may show only as a damp patch in the loft weeks later. Roofers find these by looking at the roof from close up, which is one reason a survey beats a glance from the street.
Stains, drips and damp inside the house
Internal signs often arrive before anything shows outside. A brown or yellow ring on a ceiling, paint that blisters or peels, wallpaper lifting near a chimney breast, or a drip during rain are all signs that water is already through the roof. A stain that grows after each downpour and shrinks as the ceiling dries is a strong clue.
The loft is the next place to look. A torch will show dark patches on rafters, damp or flattened insulation, and a musty smell. Wet insulation loses much of its value, so a small leak can push up heating bills before anyone notices it.
Do not assume the stain sits under the fault. Water runs along timber and underlay and comes out some way from where it entered. A stain can also come from condensation or a leaking pipe, so check those too. If the stain is spreading, or the ceiling bulges, make the room safe and move belongings first. A bulging ceiling can hold a surprising amount of water and may fall. While you wait for a roofer, the steps in emergency roof leak help limit the damage.
Daylight, sagging and movement
Standing in the loft on a bright day and seeing pinpricks of light means there are gaps in the covering. Where the gap is small it may be a worn nail hole, but light coming through at a ridge or along a hip often points to missing mortar or a failed ridge tile. Rain driven by wind will use any gap it finds.
A sagging roof line deserves more attention than a leak. If the ridge dips, a slope looks wavy, or a chimney appears to lean, the cause may be rotted timbers, a failed purlin, or a wall that has moved. A purlin is the horizontal beam that supports the rafters partway down the slope. This is a structural matter, and it needs a proper inspection promptly, not a patch.
Doors and windows that start to jam in an upstairs room can be another sign of movement, though they have many other possible causes. Raise any combination of sagging and new cracks with a roofer or a structural engineer rather than guessing.
Gutters, flashings and lead
Water does not only enter through the tiles. Gutters that overflow in ordinary rain, sag between brackets or leave green streaks down the wall are telling you that water is landing where it should not. Overflowing water soaks the fascia and the eaves timbers, and these rot quietly.
Flashings are the metal weatherings, usually lead, that seal a roof against a chimney or wall. Look for lead that has lifted, split or slipped, and for gaps in the mortar line that holds it. They are among the most common places for a leak to start, and the repair is often small if caught early.
Many older Bath terraces hide the roof behind a parapet wall and drain it through a lead-lined gutter. If you see staining on the wall below a parapet, or water marks on the top-floor ceiling, mention the gutter when you call. It is a detail that needs a roofer who knows how to work in lead.
Signs of age that can usually wait
Not every worn roof is an emergency. Moss on a north-facing slope, faded tiles, and a general softening of the colour are signs of weathering. They are worth watching and worth a survey, but they do not by themselves mean water is coming in. Moss can hold moisture against the covering, so it is worth removing carefully. Ask a roofer which cleaning method suits yours, since rough methods can harm soft tiles.
Lifespans depend on the material and how it has been looked after, and a roofer can tell you where your own roof sits in the typical range. If several worn signs appear together, a planned repair or a partial re-cover may make sense, and our roof repair guide goes through how that decision is made.
What to do next
Take dated photographs from the ground and inside the loft, note when the problem appears, and place a bucket or towels where water is coming in. Do not climb onto the roof. Some jobs are suitable for a careful owner, and our page on DIY roof repair separates those from the ones that are not.
Call 01225 285181, send a WhatsApp, or fill in the web form. A leak gets made safe before anything else, and the visit includes a free survey with pictures of your roof. Our full roof repairs service covers the rest, and a fixed price follows in writing.
