Introduction
Vacuum storage bags are meant to save space, but many users find that they slowly puff back up after sealing, either immediately or over time. This wastes time, reduces storage space, and means that the items inside the bags aren’t fully protected, leading many people to wonder whether the bags themselves are faulty.
In most cases, vacuum storage bags will re-inflate because air is entering through a tiny gap in the zip seal, valve, or plastic material. That doesn’t necessarily mean the bag is faulty; these issues can usually be fixed with the right sealing, packing, and storage method. In this article, we will cover the most common reasons vacuum storage bags re-inflate, how to prevent this, and how to know if a bag is faulty.
The Most Common Reason Vacuum Storage Bags Re-Inflate
Vacuum bags work by creating an air tight seal, then removing the majority of the air from the bag, which creates a vacuum, reduces the physical volume of the bag, and protects the contents from exposure to damp and mould. If the seal is not air tight, the bag will naturally re-inflate. A large hole will re-inflate quickly, but a tiny hole may go unnoticed until after it’s put away, resulting in you not spotting that the bag has re-inflated until weeks or possibly months later. That’s why it’s always best to leave your sealed items for a day before moving them, to check whether the vacuum bag re-inflated overnight.
The most common cause of a vacuum storage bag air leak is a zip seal problem. Although it may appear to be sealed, tiny gaps in the zip seam can remain and lead to the vacuum bag seal not closing properly and air getting back into the bag.
The best way to avoid this is to make sure that the entire seal is lying flat before closing it, as wrinkles can create gaps in the seam. After zipping closed, run your finders over the seam twice to check that it’s fully closed, paying extra attention to both ends of the seam as this is where most people miss.
Other Reasons Vacuum Storage Bags Keep Re-Inflating
The reason your vacuum bag keeps filling with air could have nothing to do with your zip seam at all. If you want to know why your vacuum bag is not compressing or staying closed, these are the most likely culprits:
The vacuum bag is overfilled
Overfilling your bag will stop the seal from sitting flat, making it difficult for you to close it properly and increasing the likelihood of gaps in the seal allowing air to pass through. To prevent this, pack all items at the bottom of the bag and leave clear space near the zip so that the seal can lay flat before closing; we recommend a gap of at least 2cm between your items and the zip.
The value is loose or not closed properly
The valve is how air is removed from a sealed bag, and it’s part of the mechanism that keeps air from getting in. A vacuum storage bag with a valve leaking will re-inflate over time. Check if the cap on the valve is loose, cross-threaded, damaged, or not pressed down properly, to prevent this issue from occurring.
The vacuum bag has a hole
If there is a hole, even just a tiny puncture or tear anywhere on the bag, then there cannot be a vacuum seal and air will naturally get into the bag. This can be caused by packing items with sharp corners or edges, buckles, heels, zips or buttons, as well as dragging the bag across the floor. Please take care that nothing you pack can damage your bag, and that you lift the bag to move it and don’t place it against anything that might damage it.
The bag material is low quality or worn
Vacuum storage bags are made of plastic and will naturally experience wear and tear over time. Some bags may degrade after heavy use and need replacing, and low-quality bags will need replacing much sooner as they are more prone to stretching, cracks, and punctures.
Drastic temperature changes
When items become hot, they expand, including air that might be trapped inside the vacuum bags. If this happens, although unlikely, it can affect the seal on your bag and cause the bag to puff up or the seal to break.
How to Fix a Vacuum Storage Bag That Has Re-Inflated
For vacuum storage bags that won’t stay flat, that are leaking air, and that won’t seal, please read on for our vacuum bag troubleshooting guide:
Step 1: Empty and inspect the zip
Dirt or debris in the zip may stop it from sealing properly. Check for dust, fibres, threads and moisture by running a clean, dry cloth over the inside of the zip.
Step 2: Repack the bag properly
Rolled clothes may create air pockets. Clothes and other items should be folded neatly and packed evenly so that the bag can compress smoothly, avoiding bulky pressure points near the zip.
Step 3: Close the seal slowly
Run the slider from one end to the other slowly, and repeat in both directions. Then, press the seal with your fingers along the entire edge, paying extra attention to both ends to check for a complete seal.
Step 4: Check the valve
Make sure that the valve cap is clean, just as with the zip. Hold the vacuum nozzle firmly over the valve while removing air, then check the valve is screwed on or pressed shut correctly.
Step 5: Check for holes
Once the bag is sealed, press gently around the bag while listening for a faint hiss sound and looking for any signs of air movement in the bag. In particular, check corners, seams, and around the zips, buttons or harder objects that may be packed inside the bag.
Step 6: Use a temporary patch as a short-term fix
If your bag has a small hole in it, you may be able to use clear tape as a temporary patch to help deal with the puncture. We would always recommend replacing a bag once it sustains a puncture, however a patch can be a great short-term solution.
How to Prevent Vacuum Storage Bags Re-Inflating Again
To prevent vacuum bag air leaks, there are lots of changes you can make to how you use vacuum bags that are very easy to implement. We have provided a list of the best vacuum storage bag tips as follows:
- Avoid overfilling the bag by choosing the right size bag for the item you need to pack. Extra-large bags are perfect for duvets, pillows and bulky bedding.
- Avoid items that aren’t suitable for long-term vacuum storage, such as hard plastic, sharp items, heels, belt buckles, and toys. Not only could these damage the items, but they could also stretch and puncture the bags.
- When bags aren’t in use, avoid folding them on the same crease lines repeatedly as this can create rips in the plastic.
- Make sure clothes are completely dry before packing, and that bags are stored in a cool, dry place to avoid damage from damp and heat.
- Fold items neatly before packing to avoid creating air pockets that can expand in heat and burst the bags.
- Do not drag vacuum storage bags across the floor as repeated scrapes will scratch and eventually rupture the plastic material.
Are Re-Inflating Vacuum Storage Bags Faulty?
Vacuum storage bags are reusable and are designed for long-term storage without breaking. Packmate's vacuum bags are made from durable materials and should last for many years without issue, which is why we provide a lifetime guarantee on our bags.
Vacuum bags may let in some air over long periods as part of normal air seepage and this does not indicate a fault with the bag, however a bag that re-inflates within hours or overnight may have a sealing, valve, or puncture issue. If your bag re-inflates, follow the directions listed above as this is more likely to be the result of debris caught in the zip, loose valves, or user error, rather than a faulty bag.
However, there are clear signs that should tell you if your bag is faulty and in need of replacement.
When to replace vacuum storage bags:
- It re-inflates after repeated careful sealing
- The zip no longer clicks shut properly
- The valve is loose or damaged
- There are visible cracks, holes or stretched areas
- The plastic feels brittle or warped
- The bag has been reused many times and no longer holds compression
Frequently Asked Questions
Why does my vacuum storage bag re-inflate overnight?
Usually because the zip seal is not fully closed, the valve is not sealed properly, the bag is overfilled, or there is a tiny puncture letting air back in.
Is it normal for vacuum bags to let air in over time?
A small amount of air returning over weeks or months can be normal. Re-inflation within hours or a day usually means there is a leak or sealing issue.
Can overfilling cause vacuum bags to leak?
Yes. Overfilling puts pressure on the zip and seams, making it harder for the seal to stay closed.
How do I know if the valve is leaking?
Check that the valve cap is clean, tight and sitting flat. If the bag re-inflates even after the zip has been checked, the valve may be the issue.
Can I repair a vacuum storage bag with tape?
A small puncture can sometimes be patched temporarily with clear tape, but it is better to replace the bag if you need reliable long-term storage.
How long should vacuum storage bags stay compressed?
Good-quality bags should stay compressed for weeks or months when sealed correctly. For long-term storage, items should be checked, aired and resealed periodically.
Choosing Quality Vacuum Storage Bags
By taking the time to pack your items carefully, double-checking that zips and valves are sealed correctly, and taking steps to prevent punctures, your bags should last for years. Packmate’s vacuum bags are intended for heavy compression and long-term storage, and are designed to be sturdy and reliable. If you are having issues with your bags that you believe are caused by low-quality materials or cheap products, we recommend giving Packmate’s storage bags a try instead, for lasting space-saving and clothing protection.