condensation in loft

[Grimreaper1]

Hi all originally put long rambling post in building forum and realized that's wrong place. Early 70's 4 bed detached with black bitumen felt under tiles and no ventilation. Never been prob before but we had bathroom renovation in summer (horrendous) with downlights and fan in loft ducting through soffit, suspect both causing but don't know who I can get to help with this am in Essex. Making me massively anxious as felt and trusses damp. Mostly dried out now but suspect will be back when cold returns.

 

[PrenticeBoyofDerry]

If you had standard downlights installed and no loft braces to support thermal insulation. It is possible that the insulation around the downlights has been removed, to offer the lamps and any connected transformers ventilation.
This would then have compromised the insulation barrier, it would be also worth checking that the inline extractor is not pumping moisture into the loft space.

 

[Grimreaper1]

Thanks I can't feel anything escaping around the ducting when fan is running and getting the condensation even if this bathroom not used. Could the ducting just be leaking water vapour from rising warm air or would that mostly be the uncovered downlights? This time of year at night before heating comes on we get some condensation on the double glazing too if it's still and frosty outside; Windows are all left open though. so as a family of 4 we are generating moisture but don't drape washing round house and use kitchen extractor. One other thought is that when our bathroom was done in the summer they buried the pipes for the wall hung basin in the thermal block wall (outside inner leaf). Not sure if insulated butt if not could condensation forming on the cold feed in the wall be causing a problem, make its way up to the loft etc?

Maybe we also need a dehumidifier in the house to cut down on condensation levels just don't know. Any more suggestions

 

[JohnD]

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