Internal windows/fanlights - how to do it (and regs)

[DavidA1982]

Hi all

I am putting a rear extension on the back of a typical 1930s detached house. The extension goes out 4m, and extends beyond the side wall of the house on the kitchen side by about 3m. It has a flat roof.

The kitchen part of the extension is very light: I've got 4.5m of bifolds and a 1.5x.2.2m roof lantern in that room. The living room part, however, is very dark. It is about 8m long, and the only source of light is a 2.3m wide bifold at the end.

Ideally I would put in a roof lantern in the living room to help, but it is already too late as the roof timbers have been put in place and the felt goes on today. The builder did say that if I can find a flat rooflight that is about 300mm wide by say 1500mm long he could fit two of them between the joists, but I can't seem to find a product that would be narrow enough.

The other option is to put in glass at the top of the stud wall that divides the kitchen and living room parts of the extension. Currently, we just have the studwork in place. I think a series of smallish glazed panels along that wall between the studs and above the noggings (which are just above head-height) would get lots of extra light in, and could look quite good. I have had a look and having double-glazing units made up at this size would be cheap - under £20 each, so for all four it would be under £100.

My question is - how do I actually fit them? I want a nice modern finish, with a sort-of frameless appearance. And are there any building regs (or, god forbid, planning permission) issues I need to consider?

Thanks

 

[chappers]

Just hold them in with thin battens the width of the reveals on each side and plasterboard over, so the whole thickness covers the black edging on the sealed units, then angle beads on the external corners and probably best with stop beads butting up to the glass and plaster the reveals.
As it's between kitchen and living check with BC if there are any fire requirement but there shouldn't be. After all you could have it open plan if you wanted

 

[daviddave]

Hi,
may be a glazing 300x1500 instead of the lantern on the living room?

 

[DavidA1982]

Thanks both. Chappers, that's really specific advice - thank you. I will ask the plasterer to do that.

David - that is what I am looking for - a thin, 300mm wide flat rooflight - I am not looking for a lantern. Unfortunately they seem to start at 600mm width!

 

[daviddave]

hi,

you should ask directly to a glazier to produce a 300x1500 mm insulated camera.

For the external pane use a 6mm tempered glass against hailstorm. For the internal pane use a layered glass 4.4

 

[JohnD]

OOI, what does a "insulated camera" look like? I have not heard of it.

 

[crank39]

OOI, what does a "insulated camera" look like? I have not heard of it.

 

[daviddave]

hi,
double glazing sorry...

 

[Gazman16]

View attachment 107059

Lol!

 

[DavidA1982]

hi,

you should ask directly to a glazier to produce a 300x1500 mm insulated camera.

For the external pane use a 6mm tempered glass against hailstorm. For the internal pane use a layered glass 4.4

Thanks Dave

I can get a double glazed sealed unit made up to the right size easily enough. It is the frame that I am struggling with! I don't think I can just use a normal window frame for a rooflight - can I?

 

[chappers]

No you can't, there are glazing bars out there but I don't know how they would work with felt, especially an already finished roof and particularly at flat roof pitches.
It's a shame as at the time of building the roof this would have been easy.
Probably best to go back to your original plan

 

[DavidA1982]

Thanks chappers. I spoke to the window fitter about it- he said he could simply fit a sealed unit on top of an upstand, with the top sheet of glass larger than the bottom (or something like that. Stuck down with industrial silicone, overlapping the roof covering.

If that is an acceptable way to do it then great.... But is it?!

 

[chappers]

Yep done that in the past myself. Get him to blacken the perimeter of inner pane with black silicone first . Then when the inside of the upstand is finished trim and scrape any excess silicone off. That way you wont see the edges of the plaster/plasterboard or the top edge of the upstand through the glass when viewed from above.

 

[DavidA1982]

Great - that's good to hear. Thanks for the tip, and giving me some comfort that this is a recognised technique. I was a bit concerned about the security issue as there is nothing mechanical fixing the pane to the building, but clearly silicone is tougher than I had realised!

 

[chappers]

yep the easiest way in would probably be to smash the glass. a solid 2" bed of silicone would be pretty strong