I would not use particle board it falls apart when it gets wet. We used 3/4" plywood painted on all sides before we put it together, 2 coats of Behrs with the primer inside. On a side note used it today on 3 lawns worked great just have a few things to rearrange. The hose is to heavy to put on the front of the box everytime. I'm going to put it on the side so it can easily be put there between jobs and then arranged when dumping the load. Also have to seal the input around the discharge tube and build a access door to see how full the box is getting. I also installed bows in the top of the tarp to expand the room in the top of the trailer. I used 1/2" pvc with the clamps that come with them. Real cheap $9.50.