How is this water getting in – window frame leaking

I have relatively new windows (<10 years old), standard uPVC double glazed. I have just noticed that water is getting inside (see pictures below). Weirdly, the water seems to be seeping in from one of the joins rather than a seal. How on earth is it doing this? The joins on the outside of the frame appear to be sound. I have never seen this sort of frame leak like this. Thank you!

And closer up…

Drains blocked on the outside and your frames are full?

Have you tried taking off the inner beading around the sealed unit to have a look? Use a decent plastic tyre lever.

Drains blocked on the outside and your frames are full?

I did wonder that (they need cleaning – it’s on my todo list) but I don’t see how that could lead to the frames getting filled with water as they are set back from the gutters. I might have to get the ladders out when my wife gets home later and unblock them and see if it does solve the issue. I haven’t taken any beading off yet – I have only just noticed this today (not had access to the room for some time) so not had an opportunity to do it.

Looks like the glass to frame seal is allowing water into the frame that’s found a way out on the inside.

Ive seen it previously where both ends of a UPVC windowsill are masticked up this can cause a blockage or the sill filling and then seeping through the join with with the UPVC window unit.

One of my windows do that, only in high winds and driving rain. Its the seal between pane and frame. These are on large framed windows though.

had identical on some new windows last year, it required the installers to remove the glass unit and clear out the drains, and in one case add a 3rd drain to the 2 that were in the factory frame.  We had it on 2 of the windows in upstairs rooms that take the brunt of the weather.  Was a simple and quick job for the guys who knew exactly the issue, took about 2 hrs to do both, incl setting up ladders etc

Under the glass there should be some drain holes in the frame. This allows any water to get out and drip onto the cill where the frame is sitting on. That’s how they are designed so the glass doesn’t have to be a watertight seal to the outside world. A decorators scraper was the go to tool for removing beads when I was working with a window fitter.

It’s stopped raining now and the water has stopped coming in – so I think that confirms that the above comments are correct – thank you!

First comment about drains refers to the holes/slots drilled on the outside of t windows.  Water runs down glass into frame , then runs out of the holes at the bottom of the frame.  These are the ones that need to be checked to see if they are blocked, not your gutters 🙂

Windows are designed to drain through the frame, the outside seal is not completely water tight. They should either drain through drain holes on the front or through holes in the bottom that marry up with holes in the sill. Water then drains through the sill to holes in the bottom in the part that overhangs. Need to clean your drain holes.

Had all of my windows replaced last week, eleven of them. The previous ones were installed in ‘93/94, and were never very good, traffic noise was very pronounced and one in a little used bedroom might as well have been left open for all the good the double glazing was!
When the fitters took the old ones out it was clear what the issue was – there was no sealing between the frame and the window aperture in the wall, the frame was only slightly wider than the wall cavity! 😳

They squirted this expanding foam, SoundFoam into the space before fitting all the plastic trim around the frames, and the difference is remarkable, there’s very little audible traffic noise now, and at night it’s just silence.
The actual glass units are about a third thicker than the old ones, so that makes a difference as well.
Fortunately never had any issues with water leaking in through the old ones, because the prevailing winds are from the SW, and drive the rain hard against the back wall of the house.

I don’t think it’s likely I’ll get any issues with water coming through these…

The frames are made by Deceuninck in Calne, they’ve been there for years, and have a great reputation, the only reason I decided to have the windows from the company who fitted them was because it was Deceuninck making the frames.

Windows are designed to drain through the frame, the outside seal is not completely water tight. They should either drain through drain holes on the front or through holes in the bottom that marry up with holes in the sill. Water then drains through the sill to holes in the bottom in the part that overhangs. Need to clean your drain holes.

Hmmm, I can’t see any drain holes on the outside.

they’ve probably got drains in the bottom of the frame then, rather than the stuck on ones on the outside. Are they tightly masticed to the cill underneath? Could be the frame and the gap under the frame are entirely full of water. I took a door frame out of our kitchen like that recently.

Some drain holes can be very well hidden – in ‘folds’ of the moulding, or indeed as cuts on the bottom of the frame where it rests on the wall or a cill.