Can you fit this type of velux window on a flat roof ?

Would it need to be mounted on an angled plinth ?

many thanks

Usually yes – the flashings and seals are designed for a pitched roof but just build up frame to suit.

needs to be on a plinth and also with a reasonable slope or water will pool on the glass and run under seals, also if you ope it all the water trapped around the edge will run in and soak you.

Velux’s site will give you the minimum slope needed, sizes, etc.

Pretty sure the instructions on ours specified a minimum angle of dangle.
edit – slow at typing it seems…

Better to use a roof light designed for flat roofs.

Sunpipes? Save overheating the room and harsh light too.

15 degrees is min pitch so you’d need a kerb kit

Yep – you need one of these: http://www.velux.co.uk/products/flat-roof-windows/flat-roof-kerb
Prob need electric operation too as the window can end up being quite high.

More spendy….but would you consider a lantern-type skylight instead?

and another thing with fitting a roof window on a flat roof is it becomes a nice entry for a burglar, enter through roof window exit through door.