Keeping Your Belongings Dry – Controlling Humidity in Storage Units

Water droplets - keep your storage unit dry

Dampness and Humidity are one of the biggest threats to keeping items pristine in storage. Our storage facilities are warm and dry, but environment isnt the only way moisture can get in. Moisture can create environments that encourage mold growth and attract pests. Although you may have packed your items carefully, materials can rot and decay over time when constantly exposed to damp conditions. This also applies to other issues such as exposure to light and how things are stacked. Boxes that are strong and sturdy now can sag over time. Especially the case in damp conditions. Before you store your items long-term, you must take care to eliminate the possibility of moisture developing.

Conditions can vary markedly throughout New Zealand. This country has a sub-tropical environment meaning that areas can experience high humidity depending on prevailing winds and weather patterns. Areas in the upper North Island have higher levels of humidity throughout the year. The following graph shows the relative humidity in Auckland over one year. This shows relative humidity between around 60% to 100%. Anything over 70% is considered high. Wellington tends to sit between 55% and 85% over the year.

Relative Humidity in Auckland

Heat and moisture encourage the growth of bacteria and mildew, which can damage upholstery, clothing, and seasonal items very quickly. To help you store with confidence, here are some suggestions to handle this problem and manage dampness and humidity in storage units.

Choose A Warm and Dry Storage Unit

The easiest way to control this problem is to choose a storage facility where the storage areas are warm and dry. Storage units do not necessarily need to be climate controlled to achieve this. A suitable facility will maintain its temperature and humidity anyway. A good tip would be to visit the facility after a period of rain and assess suitability. If you are storing items long term, visit the site regularly during this time to make sure conditions have not changed. Our units do not have power provided and so you cannot run an air conditioner or dehumidifier but our facilities are well ventilated and we suggest the use of dehumidifying agents as suggested below.

Don't Ever Store Damp or Wet Items

Have a look through items such as clothing to make sure you haven’t inadvertently picked up a batch of damp washing or items that have been stored in the damp. Missing a damp towel can wreak havoc on your belongings. This is made worse when it is inside a sealed container. Damp items make it easier for mildew and mold to grow on your belongings. Any fabrics should be washed and carefully dried before storage. If you are storing sporting gear or camping equipment, to be sure that all your items are dry, wipe them down with a towel, lay them out in the sun on a clear day, or give them a once-over with a hairdryer. Make sure you remove any soil or mud. This extra step will save you from heartache when you decide to go camping in six months time and you get your tent out of storage.

Cleaning a tent

Consider using specialised cleaners on items such as leather couches and chairs as these can accumulate finger marks and food stains which can give rise to mould or staining over time.

Leather cleaner at the box shop

Keep Contents Dry with Desiccants

Keeping items dry helps them keep for longer. This is why dried foods such as fruit or dried meat keep for longer periods of time. Within food packets you will often find a sachet of silica gel. This is an agent that sucks the moisture out of the air. This is known as a desiccant. Hardware stores sell larger desiccant packs for larger containers or rooms. They may actually be described as storage-grade silica packs. You can also make your own desiccant with charcoal. To keep your belongings dry, simply place the store-bought silica gel packs in your containers or boxes before sealing them. It can also be helpful to place a few dehumidifying containers around the storage unit to aid with the moisture-control process.

Dessicant container - damp rid
Descicant packets for use in containers

To use charcoal and make your own desicant, wrap some charcoal BBQ briquettes with fabric and store them in a box. You can also place wrapped charcoal around the storage unit to absorb moisture and get rid of bad smells. Both charcoal and silica desiccants must be replaced every two months or as needed. If you feel dampness increasing, perhaps add some additional packs. Add a few drops of vanilla or aother scented oil to the charcoal to create a pleasant odour in the space.

Making charcoal desicants

Use a Vapour Barrier

Sometimes the items you are storing need extra support, install a vapour barrier where the most moisture can sneak in. For example, if a wall of the unit is cold place a polyethylene plastic sheet on the warm side of the storage wall or put the sheet on the ground to block moisture from effecting your carboard boxes or items such as mattresses. We also recommend that mattresses and other similar items such as couches are wrapped before storage. We have a range of products suitable for this task.

Mattress and other furiniture covers

Store Items Strategically

Store every item in a way that maximizes airflow to minimize the risk of mould forming. Keep items off the ground as much as possible as suggested above. Using wooden pallets or hanging items on a rack are two excellent ways to make it possible. Shelving can also improve airflow and some shelving uses wire shelves that really helps airflow around items.

Sheling with wire shelves for airflow

Wrap as many items as possible with a plastic sheet or blanket so that there is a barrier between the item and direct open air. This takes the concept of a vapor barrier and applies it to larger items like furniture and appliances. We sell furniture covers designed for each type of item in our box shop.

Kiwi Self Storage Box Shop
Mattress Covers
Dining Chair Covers

Make sure your containers are air tight and don't have any leaks. This will extend the life of your desiccants because humid air won't reach the items inside.

Use Vacuum Sealed Bags

Whenever you take moisture out of the air, you're reducing humidity levels. You can make even bigger gains by eliminating air altogether. Vacuum seal storage bags can protect small items and clothing from moisture by eliminating their contact with air for the duration of their storage in the bag.

Vacuum bags at the box shop

These storage bags can be found in our box shop or in your local hardware store and are incredibly useful to preserve many items that are prone to moisture damage. However, be absolutely certain that everything that you store in these bags is 100% dry so that they don't develop a musty smell after you retrieve them later. If you find the vacuum bag expands after you have sealed it, discard it as it has a leak and will let in moisture over time.

Check Your Items Over Time

Be sure to check on your items every couple of months to change out desiccants and to inspect boxes for leaks. By using these preventative measures, you can store items in humid areas, lower the risk of damage and increase your peace of mind.

We're Your Best Choice for Storage and Packaging Solutions!

Kiwi Self Storage is your convenient self-storage solution. As well as commercial or residential storage we can also advise on preparing items for storage. So, contact us to arrange come into one of our facilities or give our storage experts a call at:

Give us a call today on 0800 58 57 56 or Contact Us for more information.

You can also choose the box shop at facility nearest to you and click and collect your packaging materials within 2 hours. (Not all items are available at each location).


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Making Your Own Desicants
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