Soggy Floor - help needed

[aldo]

[image]http://i749.photobucket.com/albums/xx135/Fred246/Floor1.jpg?t=1267500014[/image]
Thanks for your response- it is a removable section of floor-originally done (on the bottom)with 3/4 " plywood ribs on end and roughly 6" x 6" square plywood then glassed over. I followed chucks photo advice step by step, but still not working don't know what I am doing wrong.