Condensation at top of internal soil pipe

[80sman]

I'm after some advice.

I have a property with 2 soil stacks; one on each side of the house. Both internal, they run straight from ground level up to the loft with the relevant connections.

Once in the loft the 2 soil stacks are joined by a horizontal soil pipe laid across the ceiling joists. In the middle of this is a single soil pipe that goes up to the apex of the roof and fits within a steel shroud. The vent is on top of the apex.

I'm getting rather significant moisture from condensation forming on the roof felt and steel shroud which is dripping down onto the insulation and plasterboard below. This is obviously much worse in winter and also after someone has a shower.

Is there anyway of modifying this to stop it happening.

The house was built in 1986.

Thanks

 

[Nige F]

Soil/vent pipes ? Fan vents surely- never seen s/vp's done like that

 

[80sman]

Definitely soil stack, there were no fans installed in bathrooms when we moved in 2 years ago. I'm pretty sure it must have been built that way as I wouldn't begin to know how you would get a complete length of soil pipe into the roof space.

I would hazard a guess that the majority of the estate must be the same as I've seen no soil stacks coming out of the roofs around here. We've all got what looks like a flu vent in concrete tile material on the apex of the roof. Thinking about it the steel shroud looks more like something fitted to a flu..... although it's definitely never been used as a flu as we have a chimney for the fire and the boiler has always been mounted in the utility room with the dreaded 10mm microbore routed all under the downstairs concrete floors.

 

[Nige F]

Simply wrapping with loft insulation - ideally a bagged, non itchy type. That should stop the cold surfaces condensating.

 

[80sman]

Thanks for the advice