4 hours ago, Great_scot_selfbuild said:

Velux being cheaper than Fakro

Interesting. I'm not surprised that Fakro is highly desirable as I never had any problems, but they didn't then have the name. Architects might specify Velux without thought of any alternative.

 

That's quite a price difference / reversal though.

 

 

That's the back of my garage roof.

 

I used the " just start sheeting and see what happens approach" as it was rarely going to be seen. 

 

I cut the corrugated sheet where it landed and moved on. I used the standard keylite flashing supplied.

 

With some planning it should be possible to get the sheets to have equal gaps on both sides but for a shed I don't think anyone has ever noticed 

 

Edited August 29, 20251 yr by Iceverge

For reference I battened and counter battens the corrugated sheeting for ventilation. It happily made the roof lights more or less flush. 

 

I taped and staples the membrane appropriately over the flashing. Laid battles as required for the sheeting and cut it as square as I could to the edge. Seemed to work ok. 

11 hours ago, saveasteading said:

Architects might specify Velux without thought of any alternative.

 

Hasn't Velux become the generic name for rooflights, in the same way that Hoover has become the generic name for vacuum cleaners

3 hours ago, Bramco said:

generic name for rooflights

Yes, That was my implication. Velux, Catnic, Readymix, Celotex, and there must be many more I can't think of. 

19 hours ago, saveasteading said:

Interesting. I'm not surprised that Fakro is highly desirable as I never had any problems,

I sometimes specify Farkro on my drawings or Velux or equivalent. 

 

One thing to keep at the back of your mind is trickle ventilation if opting for the traditional route rather than a mechanical ventilation system or the like.