Wall paint bubbling on edge of window from lack of insulation, how to fix?

Question

Window and walls were done only a month ago. The only time it rained was once this week. What are these big blobs and could it be because of the light rain? Should I leave them or fix? Could it be because the window is pressed on the wall too much? I cant pop it with my fingers, and they not that squishy, the bubbled area is intact.

The bubbles right below the window rubber seal. I can see some dirt trapped in there, probably seaped through from outside.

opposite side, exterior, there is a gap between uPVC window and concrete, thats the way it was installed. no rubber seal like in the interior side. Could that be it? Would a rubber seal prevent the moisture?

Even if i were to repaint, it would be impossible seeing that the bubbles are coming from under the window where i cant reach. I read i could use a hypodermic needle and stick glue in there to make it stick, is that true?

Answer 1

What are these big blobs

Moisture has lifted the paint off the wall

and could it be because of the light rain?

Yes.

Should I leave them or fix?

Fix.

Could it be because the window is pressed on the wall too much?

No.

no rubber seal like in the interior side. Could that be it?

Yes.

Would a rubber seal prevent the moisture?

Any kind of exterior seal or sealant would. E.g. builders silicone, mastic etc. Before sealing it is necessary to remove any dirt and loose paint etc.

I read I could use a hypodermic needle and stick glue in there to make [bubbled paint] stick, is that true?

No.

Well you could, but it is unlikely to do any good. It is also likely to take longer than removing the loose paint, sanding and repainting.

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A well-made window opening has a sill that slopes outwards so that rain doesn't pool against the window. Your window opening may be badly constructed.