Hi I have at present a summer house at the bottom of the garden and the previous owner used scaffolding boards for decking and when it rains they are leathal to walk on so I have just had some new decking. These are my questions, 1) can I just lay the decking ontop of the old S/Bs and if so would it create problems later on , like retaing water between the two boards and causing them to rot . 2) Or should I rip up the S/Bs and start afresh