flexi metal duct to ridge vent (Ed.)

[shedifice]

I was in the loft looking at the vent from the shower when I found another metal spiral wound duct pipe. This duct goes from the gable wall up to a ridge vent. there is no external vent on the gable so is this vent pipe for venting the cavity? never in my whole life seen a vent from a cavity piped to somewhere else. There is not one on the oposite end of the house. This is a rubish picture but it shows the duct going into the wall with made up brick above it.

 

[blup]

How does the pipe sit/connect to the gable/cavity

 

[Exedon]

That's almost certainly a length of 'Kopex' gas flue liner.
No old gas fire place on ground floor?

 

[Nige F]

That badly wrapped hair felt needs replacing with good tubular foam lagging

 

[JohnD]

How does the pipe sit/connect to the gable/cavity

I have something similar. There are precast concrete flue blocks built into the wall (no chimneybreast) and a flue pipe comes out of the top of the wall and rises to a ridge vent.

IIRC the cross-section of the flue in the wall, is smaller than is now required for gas fires, though the flue in the loft looks like 150mm dia.

 

[shedifice]

That badly wrapped hair felt needs replacing with good tubular foam lagging

I actually think that this is a gas pipe and not a water pipe! Its a new to us house and I am slowly trying to unpick 50ish years of bodges.

 

[shedifice]

I have something similar. There are precast concrete flue blocks built into the wall (no chimneybreast) and a flue pipe comes out of the top of the wall and rises to a ridge vent.

IIRC the cross-section of the flue in the wall, is smaller than is now required for gas fires, though the flue in the loft looks like 150mm dia.

Thanks for all the responses, I think JohnD has it. The gas boiler is at that end of the house. the boiler is now in an enclose walkway between the house and garage (but vented through the garage roof, but I can totally see it being vented up inside the wall that end in the past. I will get my endoscope camera out later.

The bathroom vent is a 100mm flexi that is just poked down into the eaves with no proper vent (cowboys) so I will repurpose the ridge vent for the bathroom outlet and blank off the in wall flue. But it might be a good route for some cables down to the ground floor!

L.