I have recently completed a garden bench from blockwork that was then finished with a light coloured K-Rend. The top of the bench has red cedar battens running along the top of it. After a bit of rain, I have now noticed that the tannin from the cedar has started to stain the render, what would be the best solution to deal with this:
a. Is there something I can use to clean the render?
b. Should I have sealed the red cedar with something previously to stop the tannin secretion?
c. Should I paint over the render with something to stop the tannin seeping into it?
Thanks
