A good picket fence needs to be well constructed to ensure a long life and to look perfect in your front or back garden. Posts should be secure to hold the fence upright against the elements.
A good local company we have found to install fences in Gloucester, Cheltenham and Gloucestershire is "Cheltenham Town Tree And Landscaping Services" you can contact them via their website. http://www.cheltenhamtowntreeandlandscaping.co.uk
Other companies also install and repair picket and normal fences lots of these can be found on Why not Compare