I decided to skim one wall in my bedroom as new electrics were being put in. I've put a before and after picture, my question is why is half the room still dark after 2 weeks? I bonded the chased parts out, PVA'd the entire wall and then used Thistle multi finish once the PVA was tacky. Is there any test other than the colour of the plaster to check if it is dry? Windows have been open for 2 weeks too! Any help is appreciated. (Don't mind the skirting board)