My roof is leaking - how do I know if it’s a major problem?

My roof is leaking - how do I know if it’s a major problem?

Most people are alerted to a problem by a leaking roof. Repair seems the best option, but may not be successful in the long term. These are some things you can check:

  • Start from inside the house and see where the water is coming in. If it’s around a window or on a junction with the wall or soffit then it may be a problem with flashing in which case a simple roof repair is possible.
     
  • Have you had somebody walking on the roof recently? (eg installing a TV ariel). Roofs should be treated as fragile and any contractor needs a roofing ladder. Cracked tiles cause leaks – in this case again, roof repairs should cure the problem.
     
  • Sometimes moisture in the loft space is actually condensation, caused by inadequate ventilation. This is most common in new houses and can be cured by introducing better ventilation through the roof spaces – roof replacement should not be required. Condensation will only form in cold weather – so if you have persistent damp this is not the answer.
     
  • Are there tiles missing? Tiles should not fall off a roof. If you are finding that this is happening there may well be a problem with the fixings. The most vulnerable tiles are those around the perimeter of the roof – the verge and the top course and eaves. If you are losing tiles here then that indicates a problem with the fixings of the roof and you may have to consider re-roofing.
     
  • Is there a lot of moss or mould growth on the outside of the roof? Tiles can be forced apart by vegetation, allowing water in. Roofing repair in this situation would involve a chemical treatment of the roof to kill the moss – high pressure cleaning is not recommended as it can crack tiles.
     
  • Is the underlay rotting? Roofs rely on the underlay and the tiles working together to keep water out. If there is a single tear in the underlay then you may be able to patch it, but if it is worn out and rotting it will need replacement. This will involve a new roof as it is not possible just to replace the underlay.
     
  • Is mortar falling off the roof? Older roofs used mortar bedding for the tiles – if this starts to break down then it may be an indication that the roof is reaching the end of its life. Roofing repairs in this situation involve replacing all the mortar. This is a relatively simple process, but expensive because you will need scaffolding, and that is often the most costly part of the project. More modern roofs benefit from a dry-fix system (see later section) to prevent this problem.