The most basic job of any safe is to stop a thief walking away with your valuable items or documents.

It's obvious why you'd want to protect jewellery and other precious items. But perhaps it's less crucial to securely store documents such as birth certificates and passports than it once was, since it's easy now to scan them and keep digital copies, but nevertheless it can be important to keep and protect the originals. Sometimes these might be genuinely irreplaceable, or have sentimental value, or simply be very inconvenient to lose. And it may be the digital backup itself that you're trying to protect, such as a portable hard drive or USB sticks.

All safes offer some degree of theft protection, but in the case of very cheap and basic models the level of protection is pretty low. Many of these can be opened with a basic tool such as a screwdriver, hammer or even in some cases a magnet. A skilled locksmith (or thief) can often do this in a few seconds. In contrast, a high quality safe will not be defeated by anyone but the most determined and professional of burglars.

Important documents and other valuables aren't just susceptible to theft, but also may be destroyed in a house fire. A good fire-rated safe can protect them.

Backup or sensitive data, stored on hard drives or USB memory sticks, can also be important enough to need protection from fire. You can find lockable fire-rated data storage containers, which can be portable containers or in the form of a filing cabinet. While they are lockable, some of these may be mainly designed to protect the hard drives from fire only, not theft – for maximum protection you'll need a good quality theft and fire-rated safe for your data, just like any other valuables.

Some safes also claim to be water-proof or water-resistant. Most safes with a good fire rating (even an in-floor safe, if correctly installed) should also be reasonably resistant to water ingress, for example if the house is temporarily flooded or if fire hoses spray the safe during a house fire. Look for independent verification of any claim around water resistance.

Firearms (rifles, shotguns and pistols) are subject to strict storage requirements by law. The specific requirements are broadly similar across Australia, but can vary a bit from state to state, and depend on various factors such as the type of firearms being stored. 

We strongly recommend that if you need a gun safe, you should check the laws in your state. A good safe retailer and installer, and fellow gun club members, can also give advice.

The applicable firearm safe storage laws in each state can be found here:

• Australian Capital Territory
• New South Wales
• Northern Territory
• Queensland
• South Australia
• Tasmania
• Western Australia
• Victoria

Ideally, a safe should be positioned:

• out of sight, such as in a wardrobe, under stairs, or in a basement
• in a corner, so that it's harder for a thief to get a good angle to lever the safe out
• on a concrete floor (or subfloor).

An in-floor or in-wall safe (where the door is flush with the floor or wall) is a much bigger installation job. The same points above still apply, but you'll have a lot more work to prepare the location and to avoid any electrical wiring or plumbing. An in-floor installation into concrete could require jackhammering out a cavity and concreting the safe into place. Generally, these installations might be best left to a professional.

Avoid installing the safe in a room with dampness problems, or where a humidifier might be often used. Safes are not always air tight and high humidity can affect and damage the contents, or cause the safe itself to rust over time. Even in a room with moderate humidity, putting some silica gel packets in the safe can be a good idea to help keep the contents dry.

In most cases the safe should be anchored (fastened with bolts) to the floor or wall, or both, using the bolts supplied with the safe for this purpose. These are typically expanding bolts for anchoring into concrete or masonry – that's the most secure method. If you have to anchor to a wooden floor or wall, aim to position the bolts into a joist or stud. You may need to use long coach bolts in this case, and possibly a steel reinforcing plate on the underside of the floor.

A very heavy safe may be secure enough without being anchored to the wall or floor – typically, this would apply for a safe that's too heavy to be lifted by two or three people, or be moved with a hand trolley. For a regular home safe, industry advice generally is to anchor any safe that weighs less than 300kg.

Specific weight minimums apply for freestanding gun safes. Gun safes below these weights must be anchored to the wall and/or floor. See the links above for specific state regulations. 

For challenging locations, complicated installation, or when installing a high-quality safe to protect very valuable items, professional safe installation is a good way to go. In fact, it may be a requirement of your insurer. The costs of professional installation will vary a lot depending on the circumstances, and will add at least a few hundred dollars (probably more) in addition to the cost of the safe itself.

• If you have just a few documents or a small amount of valuables to store, these can be put into "safe custody" in a secure envelope or small lockable container which is then kept in the bank or storage company's secure facility. You can typically access your items by visiting the relevant branch in person during business hours.
• Document storage envelopes usually don't allow you to store cash. For cash, a safe custody box may be required.
• The storage fees per envelope or container vary, but typically $100 or less per year for one envelope, and more for a box.
• The bank or storage company might not provide insurance as part of the service. Check with them as to any insurance and other terms and conditions. 

• For larger amounts of valuables, or larger individual items, a safe deposit box or vault might be needed. These range in size and are offered by some banks and specialty secure storage companies.
• Fees generally start at a few hundred dollars per year and can go into the thousands for larger volume storage. Not all bank branches or storage company locations have these facilities, so contact them to find out what's available.
• With this higher level of security (and fees to match), insurance cover for the contents of the deposit box may be included in the fee.
• Check the terms and conditions for what can be stored, access options and so on.

Mark Irvine from City Safes in Sydney says that when it comes to home safes, you very much get what you pay for. "Most of the really cheap safes that you see, I could open with a screwdriver in a few seconds," he says. "You can see videos online of some cheap safes being opened with a magnet. It's very easy once you know how."

He says that very cheap safes priced a few hundred dollars or less should be regarded as lockable boxes for keeping items safe from casual theft, rather than as true safes that can deter a determined burglar.

Likewise with gun safes, Irvine says that some cheaper models might meet the requirements of the law, but aren't really as strongly built as they could be. 

He advises that anyone looking to buy a decent quality safe with genuine cash and fire ratings should be looking to spend about $700 or more.

And if you have high-end valuables to protect and insure – such as very expensive jewellery or a lot of cash – talk to your insurer first, so that you know what type of safe their policy requires. Irvine has had several clients who had to tear out and replace their safes with better ones to meet their insurance company's requirements.

Katie Eggleton, National Hook, Legs, Protect & Safety Buyer for Bunnings, says that they are seeing a shift away from mechanical access safes and an increasing interest in digital safes. "Our customers want safes that don't just provide security from theft but also will protect their valuables from weather like fire and flooding," she says.

"Entry-level digital keypad safes around the $40 price point are popular, but it really depends on what level of security customers are looking for and what items need to be secured. Customers are willing to pay more for better security features such as thicker steel, stronger hinges and locking components within the door."

She says that safes that can protect valuables from fire and floods are becoming a priority for customers. "Particularly after major flooding or bushfire events is when we typically see an increase in demand for this type of safe."

Eggleton notes that the most common problem that customers report with safes is losing access, due to forgotten codes or lost keys, but that most suppliers offer a 24-hour help line that can assist with replacements for both keys and codes.