Secondary Glazing experiment - will it work?

[dishman]

Ok, I have some old 1930s windows I would love to keep, but want to insulate a bit better.

Bog standard secondary glazing is an option and can be quite cheap, but often results in a bulky interior timber frame clad in gray aluminium.

The second option is more bespoke secondary glazing but this bumps the cost up a lot apparently.

I had discounted the diy option as being hit and miss. It would probably end up looking amateurish and be ineffective. Similar to clingfilm on the window, but only a bit better.

However, I noticed on all the windows, there is some timber detailing which results in a groove/square edge that runs around each window. This is about 15mm from the window. This is a natural frame to slot in a piece of polycarbonate sheeting. The groove width is only about 4mm wide....but should be just enough.

What are peoples thoughts as to the best way to fix the polycarbonate sheet in place? Would silicone around the 4mm groove and then some on the other side to seal it?

Or should I put some kind of rubber strip around the 4mm groove then seal the polycarbonate sheet in?

View media item 66486
That first groove is what I am talking about, it does not look much but it is just enough to hold something.

If I can get it looking good, I do not see why it would not work and look very nice...

Thoughts?

 

[Mikefromlondon]

Good idea, I would go for it, worth a try. But also keep some instruments at the ready in case of emergency escape in the event of fire or other mishaps. Silicone would be easier and less problamatic than trying to wedge a rubber gasket all around, choice is really yours.

 

[Gerrydelasel]

You don't need to seal it. An air-tight seal would make sense if the space between the panes was a vacuum, but in this case you're just trapping a layer of air, so if you seal it you will get condensation between the panes. The minute gaps should allow it to breath but still keep your warm inside air substantially separated from the cold outside glass. (If you still get condensation then you'll have to add more holes/gaps)

 

[JohnD]

I made my own dg on fixed wooden frames some years ago. You need to seal from the house side, where the warm moist air is, but not on the outdoor side, where the air is cold and dry. If the outside pane is fixed and puttied, drill the smallest possible hole at the bottom, sloping outwards so raindrops will not run it. This allows pressure equalisation with the weather. If you try to seal it perfectly, suction may draw in water. You can put a wisp of fibreglass insulation in the hole to keep dust and insects out. I also treated the hole with wood preserver in case it got damp.

Mine were (are) wooden frames so I used a wooden strip as there was no rebate, and quarter-round glazing bead painted or stained to match the window.

 

[dishman]

I had read that the window side should have ventilation. In fact I read that if you add secondary glazing, you should not add draught proofing on the windows for this reason.

I was thinking/hoping that because they are leaded windows, they may be draughty enough already without having to add extra vent holes.

 

[Gazman16]

I would go for self adhesive magnetic strips, It can then be removed fore cleaning etc.
Also if you want it to last toughened glass would be better than poly, Poly will scratch easily and go cloudy but would be the cheaper option to test.

 

[dishman]

I would go for self adhesive magnetic strips, It can then be removed fore cleaning etc.
Also if you want it to last toughened glass would be better than poly, Poly will scratch easily and go cloudy but would be the cheaper option to test.

Thanks for the though Gazman. Unfortunately as you may be able to glean from the image, the detailing on the wood frames means there are few flat edges which are a requirement for the magnetic strip type.

I considered glass, but it is so heavy, no more transparent than poly and if I get a good quality poly sheet with UV protection (and I am careful not to damage it) should not cloud over.

 

[Mikefromlondon]

Would the houses of the future not have windows at all. Windows could be made redundant. We won't have this double or triple glazing problems and we won't need curtail rails or poles, nor any curtains will be needed. Instead there will be large size LCD TV screen built into your wall, and a camera outside, so that you could see what was going on outside. You could even change between different cameras, or angles for a different image.

You could also have prerecorded screen images and pretend that your room is facing a nice sea side or shore with real waves and and the image changes its intensity according to real light conditions outside using external light sensors. This would give you a realistic effect what is outside, so when outside goes dull, the electronic window chooses an appropriate image to reflect that.

Imagine when your alarm clock goes off in the morning, what better to rise to than a yellow skies with a warm smile from the rising sun, and when dusk comes, you relax to a drink of coconut and palm trees and a setting sun with yellow clouds.

The heat from the LCD screen becomes useful to heat the room in winter, making CH radiators redundant too, and with special HAV you could have fresh air enter the room and in very cold weather, this HAV can also provide you with additional heat in winter and chilling air in hot summers.

When you are by the sea side, a fresh breeze coming in through the air grill could truly reflect your mood and as if you are almost by sea side. Sea breaze smells compressed in canister that can be made to discharges a minute spray every now and again, to make it seem real. The sound of sea gulls, and horn of a ship in the distance, Just a thought. Oh and of course when you are bored you can press a button on your electronic window and close its curtains and put on window come telly, and watch your favorite programmes. So this could be future of things to come. hum!!! may be not yet!!!