Over the summer I had my roof replaced and now my bathroom ceiling is sweating and no one took a shower. Could it be that the roof installer did something wrong?

If the ceiling is sweating, there is probably moisture from the air in the house condensing on the ceiling as it is a cool surface. The moisture could be from sources other than a shower:

* people breathing and sweating

* clothes or towels drying * water evaporating from a bath * moisture from appliances in the house, such as clothes dryers, dishwashers, cooktops/hobs * humid outside air Check the following:

* Are the main sources of moisture in the house extracted to outside the house? If so check these extracts are not leaking into the roof space. * Is the moisture coming from inside the room or is there a source in the ceiling, such as a leak, or condensation dripping off a cold surface? * Or is the roofspace not ventilated to allow any moisture to escape?

* Is there ceiling insulation that would help keep the ceiling as warm as the rest of the room? * If so was existing insulation disturbed during the roof installation and not replaced correctly? This would be a possible link beween the roof work and the sweating.