Hi All, I have replaced the bottom half of my bathroom walls with new villaboard and left the very top half of villaboard intact. The replaced villaboard extends just over my first top fixing of the shower rose and the rest is the original painted villaboard. I will tape the joints where they meet with specific waterproofing membrane but I want to know is there anyway of waterproofing the painted surface of the orginal villaboard? Is there a primer I can paint over it first before...

More...