blown DG

[Dwill]

Double glazing unit seems to have a blown seal, condensation in between the panes.

Are they repairable, is it worth it, best option?

Thanks :-)

[Invisible Man]

Recently had a fanlight go myself. Some say they are repairable but I am not convinced. Ours is being replaced.

[TheOldFellow]

This is a FAQ (frequently asked question). Some people say that you can drill holes in them and add desiccant. However the consensus is that you measure them up, and pop to your local glass supplier who will make a replacement for a reasonable sum. R.

[Andrew Gabriel]

Some will reassemble the existing glass with new desiccant spacing strips, providing the glass meets current safety regs for its location.

Common reason for failure is if the drains in the frame aren't working, and the sealed unit end's up sitting in a puddle in the frame. Whilst you have the sealed unit out, make sure water which gets in the frame can drain out. The units are normally sized to sit on glazing spacers, to make sure they are lifted clear of the drainage channels.

[Rick Hughes]

had 5 repaired last year .... al failed within 6 months .... won't repair again.

[Phil]

A local company advertises they can repair misted units without even removing them from the frame. Anyone know how they do that?

[dennis]

By imagination I would think. You need to replace the desiccant and reseal so I would say its not possible without taking it from the frame.

[Phil]

That's what I thought. too.

[Dwill]

Would they not be inserting some sort of gas that counters moisture?

[Alan Braggins]

How would you insert it in place? Drill through the frame and plug it afterwards? It might be technically possible, but I'm dubious.

[Phil]

Someone suggested to me that they drill a small hole in the glass itself. I reckon that would be very difficult/impossible.