Condensation in light fitting

[bernardgreen]

A nieghbour's light fitting has failed with heavy tracking on the terminals due to damp in the fitting.

The light fitting is a shallow dome fitting in a bedroom on a low ceiling.

Round metal plate with lampholders and rose type terminals. Cover is an opel glass bowl secured to a central threaded stud welded to the center of the circular plate.

Cables pass through grommeted hole and plaster into the space above the lath and plaster.

Found the terminal block and cables have tracked due to moisture.

No signs of damp on the ceiling and roof was recently re-felted and slated.

I think the moisture is due to cold air from the roof spacecoming into the fitting through the cable hole. Inside the fitting it is meeting warm humid air from the bedroom and condensing the vapour.

A shallow IP65 ( or near ) fitting is one option but this is a bedroom.

Any suggestions please.

Bernard
Sharnbrook

 

[holmslaw]

..

 

[bernardgreen]

The re-roofing was done a year ago and it was only this week the RCCB started tripping.

What grade / type of mastic is suitable for use round PVC cabling. I have seen PVC made brittle when surrounded by mastic.

 

[RF Lighting]

Use mastic compound. Available from most wholesalers. It is designed for use on / with cables, and is non setting so it can be removed to work on the fitting if required.

If not super super silicone to the rescue!

 

[breezer]

or a dob of blu-tac