Stiff Velux Window

[Lex Foutish]

One of our Velux windows is difficult to open, at present. It feels like the wood has swollen or that it's just stiff. Should the moving parts be lubricated with something like WD40? Has anyone else had a similar problem?

 

[AlastairSC]

Lubricating the metal hinges and arms makes sense. Then get close enough to it to hear or see what parts might be rubbing when you open and close it a few times...