In tough economic times it is necessary to protect your valuables, particularly your cash. While banks, safety deposit boxes and other such institutions can provide protection for money in your personal checking and savings accounts, a more physical protection device is required to keep your cash-on-hand protected from both theft as well as disasters such as fire. Many fireproof safes are exorbitantly and prohibitively priced, making purchase of them impossible. Fortunately you can build your own fireproof safe out of less costly materials purchased at a local DIY centre. Making your own fireproof safe requires some basic carpentry know-how, as well as simple tools and materials.
Construct a box using standard 2.5 cm (1 inch) plywood cut to your specifications. Cut opposing sides of your box so they have equivalent dimensions and adjust side sizes to account for the additional 5 cm (2 inches) of board created by the thickness of the plywood. For example, if the side walls of your box are 40 cm x 40 cm (16 inches x 16 inches), cut the front and back walls 35 cm (14 inches) wide by 40 cm (16 inches) tall, and the bottom wall and top door 35 cm (14 inches) wide by 35 cm (14 inches) tall.
Construct your box by attaching the largest walls to the second largest walls using fire resistant 3.8 cm (1 1/2 inch) or 6 mm (1/4 inch) tack nails. When the front, back and side walls are attached to each other, slide and nail the bottom of the box in place. You should use sturdier materials for the walls of your safe if you are concerned with somebody smashing it in order to gain access to your cash.
Sand an edge of the top door piece so that it is gently sloped at approximately a 45-degree angle. This sanded edge will be on the inside of the door and it will prevent the door edge from catching on the box edge as you close the door at an angle.
Attach two fire resistant hinges to the same side of the door (interior) as the sanded edge. Most hinges are attached with screws that sink into the wall. This screws will be much longer than the 2.5 cm (1 inch) plywood door will be thick. Consequently, replace the screws with a fire resistant bolt-and-nut combination of equal thickness. Be sure to install the nuts on the inside of the box to provide maximum security.
Attach the hinges to the interior of the safe, replacing the screws with bolt-and-nut combos as you did in attaching it to the door. Ensure that the safe door is able to fit flush into the opening at the top of the box, with the exception of the hinge mechanisms which will have to be clear of the box edges somewhat to function properly. This will create a small gap between the lid and the rear edge of the box.
Line the inside and outside of your safe with fire resistant type X gypsum board. This can be done with precision on all of the sides of the box with the exception of the lid, on which it will be a decidedly imprecise procedure. First, account for the lip of the box when lining so that the lid can close adequately. Second, account for the hinges of the box, which need space to function properly.
Cut a square floating lid of type X gypsum board that is 7.5 to 10 cm (3 to 4 inches) shorter on each side than the exterior of each box side, accounting for both the thickness of the box walls itself as well as the interior box lining. For example, if your box is 40 cm (16 inches) long by 40 cm (16 inches) wide by 40 cm (16 inches) high, then your floating lid will be 30 to 32.5 cm (12 to 13 inches) wide by 30 to 32.5 cm (12 to 13 inches) wide so it fits snugly into the safe.
The floating lid will fit into the box and rest on top of any and all valuables inside the box, providing additional fire protection given the gap generated by the hinges. You may even affix a handle or other device for lifting and placing the lid inside the box.
Attach a fire-resistant lock bar to the outside of the box. Anchor the lock bar by drilling through all layers of the gypsum board and box wall so that it can be attached with a nut-and-bolt combo. Recognise that both the lock bar and lock will likely be destroyed in the case of a fire, so their primary function is to provide security all the times when there isn't a fire.
Secure the box with a fire-resistant lock.