Secondly the penetration and watering can test. I’ve run about 5 litres of water from a watering can without the rose into each - about 30 seconds - and taken photos from the inside. There are 3 suspect areas - one on one side and 2 close together on the other. You can see that it’s coming through the vertical joints which are clearly not right (at least I hope you can, it’s hard to get a good photo)Ok massive thanks for helping by the way. I’ve taken loads of photos and rerun the watering can test.
Firstly the roof. There was a bit of rain last night hence slightly wet. Hopefully you can see that the sides have a “lip” to prevent water run off, this is sealed with some sort of rubbery sealant. The gutter is at the back.
If you look at the fascia you can see where water has run through in one place, this is near where the water penetrates the building. It happens on the other side but you can’t see the water as well so no picture.