Water ingress - where could the problem be?

AlCapwn

My parents live in a maisonette on 2nd floor and there is another house on top. In December 2020 following a period of heavy rain, water started entering one of the rooms, with water dripping from the white window trim and surrounding areas.

Landlord has done a bunch of work to try and fix the problem - they redid the above house balcony which is directly above the bedroom, they applied waterproofing paint and did tests with coloured water to try and trigger the problem.

A few days ago, again after a period of heavy rain, water started dripping again from the same place, so basically back to square 1. 

Back in summer 2020, they did some work which involved attaching scaffolding to the building and left behind holes which were not filled after work finished. Could this be the source of the problem? I can't find much information about it but it's a hole directly above the window area and surely can't be good for the building? They are called putlock holes according to Google

Couple of pictures - you can see internal damaged area in 2nd picture.

Murmansk

I can't make sense of the first picture really BUT where the window frame meets the building there's a gap and I suspect with heavy rain and a wind blowing in the right direction water could get in there - whether it's blown in by the wind or flowing in, encouraged by the wind, after it's run down the wall.

AlCapwn

Hi, where are you seeing a gap? I did do an inspection of the area and as far as I could tell, they have put sealent(?) in the right places.

The first picture is me trying to figure out how deep the hole is using an extendable mirror

Murmansk

I've highlighted the gap on your photo

AlCapwn

Ok thank you. I haven't gone to my parents for a while but will check this when I do.

Interestingly the next bedroom also has the same problem from the window trim and plastered areas above it. I don't know if it's sloppy work on both window replacements or something else but I will definitely check this.

sol2017

I'm not an expert so only sharing my experience. Had a similar issue with water entering from the top of the windows and it was due to blocked gutter above. Water was overflowing into the wall cavity and pooling on the top of window frames. It was fine after clearing the gutter. Until Sunday when rain downpipe above those same windows got dislodged in storm and same issue again... (gutter doctor booked).