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How to Waterproof Cardboard Boxes

How to Waterproof Cardboard Boxes

Cardboard is a thick (more than 0.2 mm) type of paper, the strength, and durability of which is due to its loose structure. It is a popular packaging material. Also, cardboard is widely used in printing, construction, and other industries. Its quality and features depend on the raw materials used and compliance with the manufacturing technology.

What is made of cardboard?

Different types of cardboard are used in:

  • quality of the packaging – boxes are made of cardboard and corrugated cardboard for any needs. Such packaging material differs in strength and shock-absorbing properties;
  • printing industry – for making covers;
  • construction – when creating a dry floor screed, to obtain heat and sound insulation layers. It is also part of the drywall.

Also, cardboard can be used in the manufacture of shoes, electrical devices, etc.

Cardboard and corrugated board are versatile materials that do not require special production costs. They are widely used in various industries. Their popularity is due to their good performance and comparatively low cost.

But cardboard is the same paper that can get wet when in contact with water and other liquids. How to make this material waterproof and water-resistant at home? We tried to find the most effective methods. Using them, you can endow cardboard or a thing made from it with waterproof properties.

This article will help you in creating homemade statues for your garden, dollhouses, postcards, preserving memorable and important papers, as well as boxes for wrapping gifts, and more. What could be even more interesting than creating a moisture-resistant layer on cardboard and products made from it?

5 ways to add a waterproof layer to cardboard

There are various ways to seal cardboard, but basically, you will have to cover every part of it that ever gets into water or even moisture, and do it completely and without even tiny gaps.

So you can seal it with waterproof liquids, or waterproof tapes (duct tape, clear packing tape, etc.), or use something like shrink wrap, or some other hard material.

The most water-resistant liquids will be permanent paints (acrylic, latex, enamels) and clear coatings such as polyurethane and epoxy resins, and even less waterproof such as thinned PVA adhesives and acrylic media, etc., will work reasonably well.

Many other pasty and other materials that are thicker or not intended for use as finishes/paints can work as well, but they will usually not be as smooth or thin.

Using PVA glue coating

One of the ways to give the cardboard the properties of moisture resistance is to cover the cardboard product with the word PVA glue. The use of PVA glue gives the cardboard a water resistance of class.

The cardboard can withstand several cycles of soaking in the rain or water and drying. For the cardboard to become waterproof, follow these steps.

Prepare your workplace. Cover the table or floor with plastic foil so as not to stain and place the cardboard product there.
Prepare a mixture of glue and water and apply the first coat to the corona surface.

Leave the cardboard to dry, apply a second coat of glue after a few hours, and check all the curves. Let the second coat dry.

To increase the waterproof properties of the cardboard, apply a third coat. Use a more concentrated solution of glue and water this time. Leave the cardboard for a day to dry completely and repeat everything. if you apply the glue correctly and in the right proportion, your cardboard is not afraid of rain and water.

Using fiberglass cover

Another way to give the board its moisture-resistant characteristics is to use fiberglass resin. This substance can be used not only for cardboard but for almost all the materials that you want to make moisture resistant.

To get started with cardboard and fiberglass resin, you need to prepare your work area. You can cover it with cling film, newspapers, or a sheet of plastic. Be sure to place a silicone mat under the cardboard. Once dry, the material can stick to anything it gets on. But it does not stick to silicone. Also wear protective gloves and clothing that you don’t mind ruining.

Now prepare a mixture of polyester resin with catalyst. Using a brush, apply the mixture to the cardboard. Make sure you cover all bends and joints tightly. Dry the cardboard within 24 hours and apply the resin mixture a second time. Leave it on for 24 hours and use water-resistant cardboard.

Using paraffin wax

Using paraffin is not the best solution to water exposure to cardboard, but many recommend it. Also, paraffin is used for waterproofing cardboard products. It can be used if you are afraid of using waterproof sprays and liquids.

Be sure to prepare your workplace. Prepare the solution. Take a saucepan, pour water on the bottom. Pour about 8 ounces of paraffin into a pot of water. Put the casserole on the fire and stir until the paraffin melts. The liquid is ready. It remains to apply a thin layer of paraffin to the cardboard with a brush and let it cool. Once the paraffin is dry, the second coat of wax can be applied.

Using Lacquer

To cover the cardboard from moisture, you can also use special liquids and sprays that are sold on the Internet. One of these sprays is Lacquer. This is a quick way to coat the cardboard and make it moisture resistant.

Prepare your workplace. It is best to cover cardboard outdoors, or in a well-ventilated room.

Spray on all sides and let the cardboard dry. This will take you a few hours. Once the cardboard is dry, you can repeat the procedure and apply a second coat of spray. You can repeat it a third time, so the layer will be even more durable.

Using the rubberized layer

Among all the available methods, it is worth noting the rubberized coating. This coating can be easily applied to cardboard products and will achieve the effect of water resistance.

Before you start, we would like to warn you that this material is toxic and therefore should only be handled outdoors.

Also, prepare your workplace, cover the surface with newspaper, plastic, or film.

Now take a brush and apply the product to the cardboard. make sure you apply the layer evenly. Dry the cardboard. Follow the instructions on the packaging and you can get the excellent waterproof properties of your cardboard product.

Comparison of Waterproofing Methods for Cardboard Boxes

The table below provides a comparison of different methods used to waterproof cardboard boxes. Waterproofing cardboard boxes is essential to protect the contents from moisture and ensure their integrity during transportation or storage. Various techniques are available to make cardboard boxes water-resistant, and this table highlights the key indicators of effectiveness for each method.

Waterproofing Method Cost Application Difficulty Durability Resistance to Water
Wax Coating Low Easy Fair Good
Plastic Liner Medium Moderate Good Excellent
Waterproof Sealant Medium Moderate Excellent Excellent
Thermal Lamination High Difficult Excellent Excellent

Explanation of the table:

  • Waterproofing Method: This column lists the different methods used to waterproof cardboard boxes.
  • Cost: This column indicates the approximate cost associated with each waterproofing method. It is categorized as low, medium, or high.
  • Application Difficulty: This column represents the level of difficulty involved in applying the waterproofing method, categorized as easy, moderate, or difficult.
  • Durability: This column assesses the longevity of the waterproofing effect provided by each method, categorized as fair, good, or excellent.
  • Resistance to Water: This column indicates the effectiveness of each method in terms of withstanding exposure to water, categorized as poor, good, or excellent.

Based on the table, we can make the following observations:

  • Wax coating is a cost-effective and relatively easy method to make cardboard boxes water-resistant. However, its durability is only fair, and it provides good resistance to water.
  • Plastic liner, though slightly more expensive and moderately difficult to apply, offers good durability and excellent resistance to water.
  • Waterproof sealant provides excellent durability and resistance to water, but it has a moderate cost and application difficulty.
  • Thermal lamination is the most expensive and difficult method to apply, but it offers excellent durability and resistance to water.

Consider these factors when choosing a waterproofing method for your cardboard boxes, depending on your budget, application requirements, and the level of protection needed.


What are the benefits of waterproofing cardboard boxes?

Waterproofing cardboard boxes provides protection against moisture, preventing damage to the contents of the box and extending its lifespan.

Which waterproofing methods are commonly used for cardboard boxes?

Commonly used waterproofing methods for cardboard boxes include using waterproof coatings, applying sealants, and using waterproof liners or bags.

Can I use regular paint to waterproof cardboard boxes?

Regular paint alone may not provide sufficient waterproofing for cardboard boxes. It is recommended to use specialized waterproof coatings or sealants specifically designed for this purpose.

How can I apply waterproof coatings to cardboard boxes?

To apply waterproof coatings to cardboard boxes, you can use a brush, roller, or spray application method. Follow the manufacturer’s instructions for the specific coating you are using.

What types of sealants can I use to waterproof cardboard boxes?

Silicone-based sealants or waterproof adhesive tapes are commonly used to seal the seams and edges of cardboard boxes, providing protection against moisture.

Are there any eco-friendly waterproofing options for cardboard boxes?

Yes, there are eco-friendly options available for waterproofing cardboard boxes. These include using water-based sealants or coatings that are non-toxic and environmentally friendly.

Can I reuse waterproofed cardboard boxes?

Yes, waterproofed cardboard boxes can be reused. However, it is important to assess the condition of the waterproofing before reuse and ensure that it is still effective.

Can I use plastic liners or bags to waterproof cardboard boxes?

Yes, using plastic liners or bags is an effective method to waterproof cardboard boxes. Simply place the items inside the plastic liner before placing them in the cardboard box.

Can I use wax to waterproof cardboard boxes?

While wax can provide some level of water resistance, it may not be the most effective method for waterproofing cardboard boxes. Specialized waterproof coatings or sealants are recommended for better results.

How long does waterproofing last on cardboard boxes?

The durability of waterproofing on cardboard boxes can vary depending on the method used, environmental conditions, and handling. It is recommended to periodically assess the waterproofing and reapply if necessary.

Are there any precautions I should take while waterproofing cardboard boxes?

When waterproofing cardboard boxes, ensure that the area is well-ventilated, and follow the safety instructions provided by the manufacturer of the waterproofing product. Additionally, avoid applying excessive moisture to the cardboard, as it can weaken the structure.

Final Words

Making cardboard waterproof is a complex process. Again, as discussed in the article, you cannot make the cardboard itself waterproof, but you can add another layer to make it waterproof.

Cardboard is not intended to be used as a waterproof material. Cardboard is paper and is susceptible to moisture and water. Constant exposure to water causes the cardboard to become wet with dirt. To expand the possibilities of cardboard and meet customer water resistance requirements, manufacturers have developed various methods of applying a waterproof coating to their products.

Having said that, there are some things you can do to make it as waterproof as possible.

Useful Video: Waterproofing a Cardboard Box

Laminate it with a thin plastic wrap. This will add weight and you need to make sure all edges are covered. Use wax. This will be the hardest to do as you will need multiple layers. You can waterproof it or paint it with epoxy. Waxing, or using a technique called cascading, which saturates the cardboard with a hot wax substance, will also make the waterproof cardboard.