What is this at the side of our house?

[RayOfFlight]

No damp in the house that I can see and not sure where the water is coming from?

@pigletjohn any idea?

it appears to be two pipes. Plastic or metal?

Are they cold? or same temperature as the wall?

Are they level or sloping?

Where do they go and what are they attached to?

Strange that it's right next to the clamp holding the top pipe onto the wall . I'd try removing the clamp ease the pipe away from the wall slightly - looks like plastic coming from a sink - and see if there is any hole in the pipe behind, against the wall.

Top plastic pipe has a hole in it where the clip is

Either that or a dog has peed up against it

Leaky pipes or gutter drip

Surely the top plastic pipe is leaking. There is no wetness above it.

How would I fix the pipe?

Temporary? Clean it and dry it, parcel tape.
Long term? Replace the pipe. They're cheap - like a tenner - and DIY shops are open around here at least.

"How would I fix the pipe?"

start by answering the questions.

Pretty sure it's coming from the plastic pipe - as people have said, a hole near the clip.

Looks like an overflow pipe to me. Would be best to trace it back to what is overflowing

Ectoplasm

It's not the overflow, that's a bit further across and seems to be working fine.

Plumber's putty in the short term probably.

A plumber would probably cut out the punctured bit and repair it with a coupling but that's a bit advanced for the moment I think!