What has caused this after glazing replaced?

[Ltnman]

In July 2022 I had some popped double glazing changed. 15 months later the rubber seals on two of the 5 windows are starting to bulge. I keep pushing them back with a fingernail but it soon bulges again. How do I get them to stay in places and was it a faulty repair for the reason for the bulging. The windows are old and the beading is on the outside. The guy changed the glass without climbing a ladder. After he finished I found a blue packing piece on the lawn.

 

[ronniecabers]

If externally beaded then that's a ' wedge ' gasket and is designed to be removed , as the name suggests its wedged in. When it next pops out , get something like a wooden spoon handle and give it a firm push, it may be its just not locating on the groove correctly and in the changing heat conditions moving around and then popping out

 

[crank39]

Was the gasket replaced also or is it the original? Essentially it's because the gasket is too long and is being forced out, if the gasket has been replaced then its ALWAYS good practice to cut it long and force it in so when it inevitably shrinks then it doesn't pull away from the corners, IF it's the original gasket then it could be something as simple as each end hasn't been pushed into the corners enough and as a consequence is too long and is bulging out

 

[Ltnman]

Thanks for the answers. All the gaskets were changed from white to black around 6 or 7 years ago. I will try the spoon method later today and if that does not work will try pushing the gasket more into the corners by pulling back a length

 

[ahow35]

If the wedge gasket keeps popping out, then it could be too big for the gap. These seals are usually identified by the size of the gap that they push into but there is only a tiny difference (literally a mm) between each version. Could it be that the wrong size was fitted 6 years ago?

If you are using a 5mm wedge gasket, maybe try something like a 4mm.

If you can't measure the gap (its sometimes quite awkward) try measuring the solid piece of rubber directly in the middle of the gasket. You can then look at drawings of other wedge gaskets, work out what size you have, then find some a fraction smaller.