The upvc plastic coating on one of my external window sills is badly damaged. It has basically cracked and rotted away. The rest of the window is fine and I don't want to replace the whole window if I don't need to. Is there anything I can do to either repair this or cover it. Any suggestions would be greatly appreciated.
You could replace the cill, in order to do this the window frame and glass needs to be removed then refitted. A picture would be helpful.
If it was fitted properly and not screwed through the frame into it, then you can remove the cil without touching the window at all, you will need the remove a course of bricks below the cil and it then should drop down and slide out.
Is there nothing it can be re-covered with, like a stick on upvc coating, Ive seen lots of people asking for it but does it exist?
You could try vinyl wrap the stuff they use on cars. Like this. http://m.ebay.co.uk/itm/WHITE-Gloss-Vehicle-Wrap-Vinyl-610MM-X-1000MM-1-METER-/190596761775
They are clipped to the frame, there shouldn't be any screws used, so as I said remove bricks and it should drop down and slide out.
if you search - Replacing External Upvc Sill , on the Screwfix community web site should find a thread with loads of info in relation to this matter. There is a very good chance you could get the old cill off without removing window or a course of bricks from below, however depending how the cill has been fitted to frame (or if) and how tight the frame and cill are to brick work below will make the difference between easy job and right pain the backside. photo of window and underside of cill externally would help.
You do not know what you are talking about, you don't clip a cill to a window . You screw the cill to the window first then fix down with concrete screws using your level to make sure you don't bow the frame (Phil the paver) please read FENSA installing guide or the Plastic window federation guide. We supply and install cover trims for all upvc external cills if they are damaged or discoloured. Wise Designs In Glass Ltd.