The old sill and rotten wood is removed from the frame and I packet in the parts of the frame that had go rotten with new timber. I then cut down to size a treated 3×4 inch timber, giving a slop away from the window and cutting a grove on the under side for water dispersal. I then use wooden trim around the glass and sealed with frame sealant. The sill was screwed on from inside the window using 120 mm screw.
Just needs frame sealant applied & top coat of gloss exterior paint. Look great and the customer didn’t need to purchase a new window. Job done at the fraction of the price!