Keeping valuables inside your house is a risk unless you have a very resilient safe or an advanced home security system. Keeping them in a safety deposit box at a bank works well unless you are concerned about a large-scale catastrophe that might cause banks to close.
In such a situation, burying your valuables in the back garden is a viable alternative, but you must take precautions to protect your things from moisture, insects and other things that might cause damage or degradation over time. PVC pipe capsules can protect your buried valuables inexpensively.
Cut a 45-cm (18-inch) or shorter length of 15-cm (6-inch) PVC pipe with a hacksaw. Make the length of pipe as small as you can while still accommodating the valuables you wish to store.
Rub the outside ends of the PVC pipe and the inside of two round PVC cap ends with steel wool or fine sandpaper. This will allow a secure bond when you seal the ends with PVC pipe cement.
Apply a generous amount of PVC pipe cement to the pipe end and the inside of one cap. Seal the end cap on the PVC pipe and allow it to dry according to the pipe cement manufacturer's directions.
Seal your valuables in vacuum bags with a packet of desiccant. Inexpensive vacuum hand pumps that work with special resealable bags are available from most department stores. Hardware and sporting good stores sell desiccant.
Pack your vacuum-sealed valuables in the PVC pipe. Fill the pipe tightly to avoid large air spaces. Add additional desiccant packets to the pipe.
Apply PVC pipe cement to the open end of the pipe and the inside of the remaining end cap. Seal the PVC capsule and allow the cement to dry.
Dig a hole at least 90 cm (36 inches) deep and slightly larger in diameter than the PVC pipe. An auger-style post hole digger works well.
Place the PVC capsule in the bottom of the hole. Fill the hole completely and stamp it down with your feet or a piece of scrap wood.
Mark the site of the hole with something you will not forget. Plant a perennial over the site or place a large rock next to it.
Make sure your marker is something that cannot easily be moved or destroyed. It should also fit its surroundings and not look out of place to a stranger. When opening your backyard safety deposit box, use a hacksaw to open the PVC capsule. Saw carefully around the end of the pipe, right next to the end cap.
Unlike a safety deposit box at a bank, there is no recourse if you forget where your valuables are buried in your backyard or if they are damaged in any way.