Velux on kitchen roof

[jackg]

The exsting windows are small and on one side only so the room is dark.
Trusses are 400mm. I have seen pictures with Velux spanning 2-3 trusses but with no noggins.
So do Velux make bespoke windows such as 400 wide, as the std ones are 550 minimum, or is it best to span more than one truss?

 

[Bonni]

If on a new roof I'm building, I double up the rafters on either side of the rafter that's cut and trimmed because of the velux.

With existing plasterboard and roof tiles in place, doubling rafters would be nigh on impossible without removing plasterboard or roofing material. Would not doubling up be an issue? Doubt it but not 100% sure. So a velux spanning across a rafter, the rafter just needs cut and trimmed. Trimmed means a horizontal noggin between the two rafters to attach the cut rafter to (a trimmer at the top and a trimmer at the bottom).

The reveal at the top of the velux should be as horizontal as possible, and the bottom reveal as vertical as possible to allow maximum light in.

And an external trim kit that's suitable for the size of velux, the tiles, and pitch.

 

[catlad]

Depending what size you already have you could increase it to the largest size in that range 55 x 120
Velux also so do combi flashing kits so you could have two side by side.

 

[PMV Maintenance]

Hi, You would need to remove at least one rafter allowing (based upon 400mm gap) giving you a width of 857mm approx. fit an MK width VELUX window as minimum (height depends on space) You will need to add extra rafters either one inside (new width 800 approx) and one outside. this needs to be supported top and bottom either to wall plate and apex or to purling supports (Poss structural engineers drawing required for complex roof designs) Rafters need bolting and double trimmers top and bottom with mechanical fixings, timber to match existing spaced to allow maximum plasterboard spread and insulation. Building Control will need to be informed and project signed off, if in a conservation area this will also need to be checked. Planning required if it overlooks a neighbour on left or right of property. Also it cannot be sited next to a flue pipe.
Regards Phil.