Anyone used pitched roof windows on a flat roof?

[AdTee]

I'm sending out for posi joist quotes and have decided for various reasons that I'd rather have several smaller rooflights than the large one originally spec'd (approx 3m x 1.6m).

I've looked at many options including standard opening and non-opening flat roof windows, and I've now started looking into using pitched rooflights on a sloping upstand. I asked Keylite who said 'A standard centre pivot roof window can be fitted to site formed, provided the site formed upstand is fabricated at a 15° fall across the roof window.' 

Does anyone have any experiences or thoughts on this idea, please?

Thanks

[Nickfromwales]

13 hours ago, AdTee said:

I'm sending out for posi joist quotes and have decided for various reasons that I'd rather have several smaller rooflights than the large one originally spec'd (approx 3m x 1.6m).

I've looked at many options including standard opening and non-opening flat roof windows, and I've now started looking into using pitched rooflights on a sloping upstand. I asked Keylite who said 'A standard centre pivot roof window can be fitted to site formed, provided the site formed upstand is fabricated at a 15° fall across the roof window.' 

Does anyone have any experiences or thoughts on this idea, please?

Thanks

Just meet the manufacturers installation criteria and you're good to go? Nothing stopping you at all.

 

Standard 'flat' non-openers are simple and robust, but tbh you'll prob want at least 1 to be openable.

 

Not sure how the light would travel through multiples of sloped units vs one big central lantern, but that's your choice of course. Also consider lighting plans and how this arrangement would affect that.

[AdTee]

On 10/07/2025 at 10:48, Nickfromwales said:

Just meet the manufacturers installation criteria and you're good to go? Nothing stopping you at all.

 

Standard 'flat' non-openers are simple and robust, but tbh you'll prob want at least 1 to be openable.

 

Not sure how the light would travel through multiples of sloped units vs one big central lantern, but that's your choice of course. Also consider lighting plans and how this arrangement would affect that.

Useful advice, thanks very much.