Woodlap Brown Fence Panel 6ftx2ft Dip TreatedDip treatment is the most common method of applying preservative to timber in bulk. With this technique, all the wooden components that will make up the shed are dipped into a tank of either water-based or solvent-based preservative before the panels are put together. Dip treating achieves a similar result to brushing or spraying the preservative on to the shed, but is carried out in advance at the factory ? saving buyers time and effort. The dip-treating process is quicker, simpler and less expensive to carry out than pressure-treating. Labour and storage costs are lower, making this type of shed popular and affordable.