Outside cladding reduced broadband speed

[lettice]

Have a friend who moved into a house a few months back that has outside block plaster/paint cladding over brick and their phone cable was channelled down the edge of it.
They noticed that their broadband speed was half the speed of their neighbours, all similar properties and layout.
They had a openreach engineer who checked the line with a house visit and said they could not improve it.
During last week, they had sky q fitted and the engineer mentioned something to him that his cladding was inhibiting the phone line and looked slightly damp with condensation.
At that point my friend eased out the phone line cable and re nailed it to brick, just next to where the sky engineer put the sky q cables.
His line immediately increased in speed.
After a few days and he mentioned a reset by sky, he now has the same line speed as his neighbours.

He showed me the cladding today and where the phone line was touching it.
Did not think that slight condensation would have such a big effect.

Nice to hear a sky engineer going the extra mile with advice like that.
Not sure why the openreach engineer could not have seen that or run a new cable from pole to premises.

[AvoriazSkier]

Only thing I can think of is that the moisture altered the capacitance of the line which might have affected line speed. I'm just a lowly physicist so don't know much about wave propagation in copper pairs.

[The Realist]

Moisture or water ingress will decrease line speeds up and down.

[BurnIT]

Also I would think that if the twisted pair were "squeezed" by the cladding the insulation between them could have deteriated and moving it could have allowed separation again.