Upstand for roof lantern

[Notch7]

we are doing a build with a roof lantern the size we are having is 3.2x1.2m the manufacture only give the external measurements not the internal. The carpenter has constructed an upstand but the internal measurement is 96cm he said he does this so the plasterboard can be packed out and to allow adjustment to get the lantern square? But that of course makes the internal measurement a lot narrower. Is that correct?

No it's wrong.

The lantern will be square.

The thickness of the upstanding is determined by the lantern baseplate and you need the manufacturer to tell you what that is.

Is it Korniche?

 

[freddiemercurystwin]

it is a professional company, they supply most of the trade.

If they were professional they'd be able to tell you the sizes and all of their typical installation details, product data sheets etc would be available to anyone requiring them. It's no good getting all defensive, if we don't know the manufacturer or model then we're unable to help any more than we have.

 

[essex123456]

No it's wrong.

The lantern will be square.

The thickness of the upstanding is determined by the lantern baseplate and you need the manufacturer to tell you what that is.

Is it Korniche?

Hi yes it's a korniche, I have the data sheet but it didn't give internal and when I spoke to them the don't give the internal only external size.

 

[essex123456]

If they were professional they'd be able to tell you the sizes and all of their typical installation details, product data sheets etc would be available to anyone requiring them. It's no good getting all defensive, if we don't know the manufacturer or model then we're unable to help any more than we have.

They are professional it's made for trade korniche. For some reason they don't give internal size. I rang them up they only give external

 

[^woody^]

Internals are not given because the thickness of the upstand is discretionary. It could be a thin upstand, a thicker insulated panel or timber frame, or a section of glazed frame.

What should be given is details of the cill/plate width and fixing details, and from that you can work out the position and thickness of the upstand. There is normally a sectional drawing available to depict this.

I'd suggest that the upstand as built, is narrower than it could be.

 

[freddiemercurystwin]

https://www.korniche.co.uk/wp-content/uploads/2021/03/Korniche-Surveying-Guide.pdf

 

[essex123456]

Thanks for the replies. I understand about the thickness of the upstand being discretionary. I've attached a photo the white line is 70mm which is the minimum, silly question but is it possible to cut the upstand back to this? Particularly on the longer side? I'm trying to get as much light in as I can. I was a bit silly trusting the chippy.

 

[essex123456]

https://www.korniche.co.uk/wp-content/uploads/2021/03/Korniche-Surveying-Guide.pdf

Thanks I have seen that, my problem is the chippy has constructed it thicker than the 69mm minimum. I'm trying to maximize the light I get.