won't dry

I decided to skim one wall of my bedroom which had some new wall lights and sockets moved around. I PVA'd and bonded the chased walls first then applied PVA to the entire wall and skim coated it with Thistle Multi finish once the PVA was tacky. I have attached before and after pictures (don't...

Hi, We have had this patch taken back to the brick, it’s been PVA’d twice with other treatments on this occasion. It’s not coming from outside, above or below. A company called Britainia have checked it out. It’s only ever that patch, nowhere else. Short of knocking the whole wall down any...